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FAILED: patch "[PATCH] platform/x86: ideapad-laptop: use usleep_range() for EC" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 5808c34216954cd832bd4b8bc52dfa287049122b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062034-morbidity-saddling-e68c@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5808c34216954cd832bd4b8bc52dfa287049122b Mon Sep 17 00:00:00 2001 From: Rong Zhang <i(a)rong.moe> Date: Mon, 26 May 2025 04:18:07 +0800 Subject: [PATCH] platform/x86: ideapad-laptop: use usleep_range() for EC polling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It was reported that ideapad-laptop sometimes causes some recent (since 2024) Lenovo ThinkBook models shut down when: - suspending/resuming - closing/opening the lid - (dis)connecting a charger - reading/writing some sysfs properties, e.g., fan_mode, touchpad - pressing down some Fn keys, e.g., Brightness Up/Down (Fn+F5/F6) - (seldom) loading the kmod The issue has existed since the launch day of such models, and there have been some out-of-tree workarounds (see Link:) for the issue. One disables some functionalities, while another one simply shortens IDEAPAD_EC_TIMEOUT. The disabled functionalities have read_ec_data() in their call chains, which calls schedule() between each poll. It turns out that these models suffer from the indeterminacy of schedule() because of their low tolerance for being polled too frequently. Sometimes schedule() returns too soon due to the lack of ready tasks, causing the margin between two polls to be too short. In this case, the command is somehow aborted, and too many subsequent polls (they poll for "nothing!") may eventually break the state machine in the EC, resulting in a hard shutdown. This explains why shortening IDEAPAD_EC_TIMEOUT works around the issue - it reduces the total number of polls sent to the EC. Even when it doesn't lead to a shutdown, frequent polls may also disturb the ongoing operation and notably delay (+ 10-20ms) the availability of EC response. This phenomenon is unlikely to be exclusive to the models mentioned above, so dropping the schedule() manner should also slightly improve the responsiveness of various models. Fix these issues by migrating to usleep_range(150, 300). The interval is chosen to add some margin to the minimal 50us and considering EC responses are usually available after 150-2500us based on my test. It should be enough to fix these issues on all models subject to the EC bug without introducing latency on other models. Tested on ThinkBook 14 G7+ ASP and solved both issues. No regression was introduced in the test on a model without the EC bug (ThinkBook X IMH, thanks Eric). Link: https://github.com/ty2/ideapad-laptop-tb2024g6plus/commit/6c5db18c9e8109873… Link: https://github.com/ferstar/ideapad-laptop-tb/commit/42d1e68e5009529d31bd23f… Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218771 Fixes: 6a09f21dd1e2 ("ideapad: add ACPI helpers") Cc: stable(a)vger.kernel.org Tested-by: Felix Yan <felixonmars(a)archlinux.org> Tested-by: Eric Long <i(a)hack3r.moe> Tested-by: Jianfei Zhang <zhangjianfei3(a)gmail.com> Tested-by: Mingcong Bai <jeffbai(a)aosc.io> Tested-by: Minh Le <minhld139(a)gmail.com> Tested-by: Sicheng Zhu <Emmet_Z(a)outlook.com> Signed-off-by: Rong Zhang <i(a)rong.moe> Link: https://lore.kernel.org/r/20250525201833.37939-1-i@rong.moe Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c index ede483573fe0..b5e4da6a6779 100644 --- a/drivers/platform/x86/ideapad-laptop.c +++ b/drivers/platform/x86/ideapad-laptop.c @@ -15,6 +15,7 @@ #include <linux/bug.h> #include <linux/cleanup.h> #include <linux/debugfs.h> +#include <linux/delay.h> #include <linux/device.h> #include <linux/dmi.h> #include <linux/i8042.h> @@ -267,6 +268,20 @@ static void ideapad_shared_exit(struct ideapad_private *priv) */ #define IDEAPAD_EC_TIMEOUT 200 /* in ms */ +/* + * Some models (e.g., ThinkBook since 2024) have a low tolerance for being + * polled too frequently. Doing so may break the state machine in the EC, + * resulting in a hard shutdown. + * + * It is also observed that frequent polls may disturb the ongoing operation + * and notably delay the availability of EC response. + * + * These values are used as the delay before the first poll and the interval + * between subsequent polls to solve the above issues. + */ +#define IDEAPAD_EC_POLL_MIN_US 150 +#define IDEAPAD_EC_POLL_MAX_US 300 + static int eval_int(acpi_handle handle, const char *name, unsigned long *res) { unsigned long long result; @@ -383,7 +398,7 @@ static int read_ec_data(acpi_handle handle, unsigned long cmd, unsigned long *da end_jiffies = jiffies + msecs_to_jiffies(IDEAPAD_EC_TIMEOUT) + 1; while (time_before(jiffies, end_jiffies)) { - schedule(); + usleep_range(IDEAPAD_EC_POLL_MIN_US, IDEAPAD_EC_POLL_MAX_US); err = eval_vpcr(handle, 1, &val); if (err) @@ -414,7 +429,7 @@ static int write_ec_cmd(acpi_handle handle, unsigned long cmd, unsigned long dat end_jiffies = jiffies + msecs_to_jiffies(IDEAPAD_EC_TIMEOUT) + 1; while (time_before(jiffies, end_jiffies)) { - schedule(); + usleep_range(IDEAPAD_EC_POLL_MIN_US, IDEAPAD_EC_POLL_MAX_US); err = eval_vpcr(handle, 1, &val); if (err)

2 weeks, 2 days

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FAILED: patch "[PATCH] platform/x86: ideapad-laptop: use usleep_range() for EC" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 5808c34216954cd832bd4b8bc52dfa287049122b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062033-fedora-humbly-2cc5@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5808c34216954cd832bd4b8bc52dfa287049122b Mon Sep 17 00:00:00 2001 From: Rong Zhang <i(a)rong.moe> Date: Mon, 26 May 2025 04:18:07 +0800 Subject: [PATCH] platform/x86: ideapad-laptop: use usleep_range() for EC polling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It was reported that ideapad-laptop sometimes causes some recent (since 2024) Lenovo ThinkBook models shut down when: - suspending/resuming - closing/opening the lid - (dis)connecting a charger - reading/writing some sysfs properties, e.g., fan_mode, touchpad - pressing down some Fn keys, e.g., Brightness Up/Down (Fn+F5/F6) - (seldom) loading the kmod The issue has existed since the launch day of such models, and there have been some out-of-tree workarounds (see Link:) for the issue. One disables some functionalities, while another one simply shortens IDEAPAD_EC_TIMEOUT. The disabled functionalities have read_ec_data() in their call chains, which calls schedule() between each poll. It turns out that these models suffer from the indeterminacy of schedule() because of their low tolerance for being polled too frequently. Sometimes schedule() returns too soon due to the lack of ready tasks, causing the margin between two polls to be too short. In this case, the command is somehow aborted, and too many subsequent polls (they poll for "nothing!") may eventually break the state machine in the EC, resulting in a hard shutdown. This explains why shortening IDEAPAD_EC_TIMEOUT works around the issue - it reduces the total number of polls sent to the EC. Even when it doesn't lead to a shutdown, frequent polls may also disturb the ongoing operation and notably delay (+ 10-20ms) the availability of EC response. This phenomenon is unlikely to be exclusive to the models mentioned above, so dropping the schedule() manner should also slightly improve the responsiveness of various models. Fix these issues by migrating to usleep_range(150, 300). The interval is chosen to add some margin to the minimal 50us and considering EC responses are usually available after 150-2500us based on my test. It should be enough to fix these issues on all models subject to the EC bug without introducing latency on other models. Tested on ThinkBook 14 G7+ ASP and solved both issues. No regression was introduced in the test on a model without the EC bug (ThinkBook X IMH, thanks Eric). Link: https://github.com/ty2/ideapad-laptop-tb2024g6plus/commit/6c5db18c9e8109873… Link: https://github.com/ferstar/ideapad-laptop-tb/commit/42d1e68e5009529d31bd23f… Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218771 Fixes: 6a09f21dd1e2 ("ideapad: add ACPI helpers") Cc: stable(a)vger.kernel.org Tested-by: Felix Yan <felixonmars(a)archlinux.org> Tested-by: Eric Long <i(a)hack3r.moe> Tested-by: Jianfei Zhang <zhangjianfei3(a)gmail.com> Tested-by: Mingcong Bai <jeffbai(a)aosc.io> Tested-by: Minh Le <minhld139(a)gmail.com> Tested-by: Sicheng Zhu <Emmet_Z(a)outlook.com> Signed-off-by: Rong Zhang <i(a)rong.moe> Link: https://lore.kernel.org/r/20250525201833.37939-1-i@rong.moe Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c index ede483573fe0..b5e4da6a6779 100644 --- a/drivers/platform/x86/ideapad-laptop.c +++ b/drivers/platform/x86/ideapad-laptop.c @@ -15,6 +15,7 @@ #include <linux/bug.h> #include <linux/cleanup.h> #include <linux/debugfs.h> +#include <linux/delay.h> #include <linux/device.h> #include <linux/dmi.h> #include <linux/i8042.h> @@ -267,6 +268,20 @@ static void ideapad_shared_exit(struct ideapad_private *priv) */ #define IDEAPAD_EC_TIMEOUT 200 /* in ms */ +/* + * Some models (e.g., ThinkBook since 2024) have a low tolerance for being + * polled too frequently. Doing so may break the state machine in the EC, + * resulting in a hard shutdown. + * + * It is also observed that frequent polls may disturb the ongoing operation + * and notably delay the availability of EC response. + * + * These values are used as the delay before the first poll and the interval + * between subsequent polls to solve the above issues. + */ +#define IDEAPAD_EC_POLL_MIN_US 150 +#define IDEAPAD_EC_POLL_MAX_US 300 + static int eval_int(acpi_handle handle, const char *name, unsigned long *res) { unsigned long long result; @@ -383,7 +398,7 @@ static int read_ec_data(acpi_handle handle, unsigned long cmd, unsigned long *da end_jiffies = jiffies + msecs_to_jiffies(IDEAPAD_EC_TIMEOUT) + 1; while (time_before(jiffies, end_jiffies)) { - schedule(); + usleep_range(IDEAPAD_EC_POLL_MIN_US, IDEAPAD_EC_POLL_MAX_US); err = eval_vpcr(handle, 1, &val); if (err) @@ -414,7 +429,7 @@ static int write_ec_cmd(acpi_handle handle, unsigned long cmd, unsigned long dat end_jiffies = jiffies + msecs_to_jiffies(IDEAPAD_EC_TIMEOUT) + 1; while (time_before(jiffies, end_jiffies)) { - schedule(); + usleep_range(IDEAPAD_EC_POLL_MIN_US, IDEAPAD_EC_POLL_MAX_US); err = eval_vpcr(handle, 1, &val); if (err)

2 weeks, 2 days

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FAILED: patch "[PATCH] x86/its: explicitly manage permissions for ITS pages" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x a82b26451de126a5ae130361081986bc459afe9b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062014-smuggler-flip-4aaf@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a82b26451de126a5ae130361081986bc459afe9b Mon Sep 17 00:00:00 2001 From: "Peter Zijlstra (Intel)" <peterz(a)infradead.org> Date: Tue, 3 Jun 2025 14:14:44 +0300 Subject: [PATCH] x86/its: explicitly manage permissions for ITS pages execmem_alloc() sets permissions differently depending on the kernel configuration, CPU support for PSE and whether a page is allocated before or after mark_rodata_ro(). Add tracking for pages allocated for ITS when patching the core kernel and make sure the permissions for ITS pages are explicitly managed for both kernel and module allocations. Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Co-developed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Reviewed-by: Nikolay Borisov <nik.borisov(a)suse.com> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-5-rppt@kernel.org diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index b50fe6ce4655..6455f7f751b3 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -116,6 +116,24 @@ static struct module *its_mod; #endif static void *its_page; static unsigned int its_offset; +struct its_array its_pages; + +static void *__its_alloc(struct its_array *pages) +{ + void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); + if (!page) + return NULL; + + void *tmp = krealloc(pages->pages, (pages->num+1) * sizeof(void *), + GFP_KERNEL); + if (!tmp) + return NULL; + + pages->pages = tmp; + pages->pages[pages->num++] = page; + + return no_free_ptr(page); +} /* Initialize a thunk with the "jmp *reg; int3" instructions. */ static void *its_init_thunk(void *thunk, int reg) @@ -151,6 +169,21 @@ static void *its_init_thunk(void *thunk, int reg) return thunk + offset; } +static void its_pages_protect(struct its_array *pages) +{ + for (int i = 0; i < pages->num; i++) { + void *page = pages->pages[i]; + execmem_restore_rox(page, PAGE_SIZE); + } +} + +static void its_fini_core(void) +{ + if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) + its_pages_protect(&its_pages); + kfree(its_pages.pages); +} + #ifdef CONFIG_MODULES void its_init_mod(struct module *mod) { @@ -173,10 +206,8 @@ void its_fini_mod(struct module *mod) its_page = NULL; mutex_unlock(&text_mutex); - for (int i = 0; i < mod->arch.its_pages.num; i++) { - void *page = mod->arch.its_pages.pages[i]; - execmem_restore_rox(page, PAGE_SIZE); - } + if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) + its_pages_protect(&mod->arch.its_pages); } void its_free_mod(struct module *mod) @@ -194,28 +225,23 @@ void its_free_mod(struct module *mod) static void *its_alloc(void) { - void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); + struct its_array *pages = &its_pages; + void *page; +#ifdef CONFIG_MODULE + if (its_mod) + pages = &its_mod->arch.its_pages; +#endif + + page = __its_alloc(pages); if (!page) return NULL; -#ifdef CONFIG_MODULES - if (its_mod) { - struct its_array *pages = &its_mod->arch.its_pages; - void *tmp = krealloc(pages->pages, - (pages->num+1) * sizeof(void *), - GFP_KERNEL); - if (!tmp) - return NULL; + execmem_make_temp_rw(page, PAGE_SIZE); + if (pages == &its_pages) + set_memory_x((unsigned long)page, 1); - pages->pages = tmp; - pages->pages[pages->num++] = page; - - execmem_make_temp_rw(page, PAGE_SIZE); - } -#endif /* CONFIG_MODULES */ - - return no_free_ptr(page); + return page; } static void *its_allocate_thunk(int reg) @@ -269,7 +295,9 @@ u8 *its_static_thunk(int reg) return thunk; } -#endif +#else +static inline void its_fini_core(void) {} +#endif /* CONFIG_MITIGATION_ITS */ /* * Nomenclature for variable names to simplify and clarify this code and ease @@ -2339,6 +2367,8 @@ void __init alternative_instructions(void) apply_retpolines(__retpoline_sites, __retpoline_sites_end); apply_returns(__return_sites, __return_sites_end); + its_fini_core(); + /* * Adjust all CALL instructions to point to func()-10, including * those in .altinstr_replacement.

2 weeks, 2 days

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FAILED: patch "[PATCH] x86/its: explicitly manage permissions for ITS pages" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x a82b26451de126a5ae130361081986bc459afe9b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062014-unvaried-ranch-2d7c@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a82b26451de126a5ae130361081986bc459afe9b Mon Sep 17 00:00:00 2001 From: "Peter Zijlstra (Intel)" <peterz(a)infradead.org> Date: Tue, 3 Jun 2025 14:14:44 +0300 Subject: [PATCH] x86/its: explicitly manage permissions for ITS pages execmem_alloc() sets permissions differently depending on the kernel configuration, CPU support for PSE and whether a page is allocated before or after mark_rodata_ro(). Add tracking for pages allocated for ITS when patching the core kernel and make sure the permissions for ITS pages are explicitly managed for both kernel and module allocations. Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Co-developed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Reviewed-by: Nikolay Borisov <nik.borisov(a)suse.com> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-5-rppt@kernel.org diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index b50fe6ce4655..6455f7f751b3 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -116,6 +116,24 @@ static struct module *its_mod; #endif static void *its_page; static unsigned int its_offset; +struct its_array its_pages; + +static void *__its_alloc(struct its_array *pages) +{ + void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); + if (!page) + return NULL; + + void *tmp = krealloc(pages->pages, (pages->num+1) * sizeof(void *), + GFP_KERNEL); + if (!tmp) + return NULL; + + pages->pages = tmp; + pages->pages[pages->num++] = page; + + return no_free_ptr(page); +} /* Initialize a thunk with the "jmp *reg; int3" instructions. */ static void *its_init_thunk(void *thunk, int reg) @@ -151,6 +169,21 @@ static void *its_init_thunk(void *thunk, int reg) return thunk + offset; } +static void its_pages_protect(struct its_array *pages) +{ + for (int i = 0; i < pages->num; i++) { + void *page = pages->pages[i]; + execmem_restore_rox(page, PAGE_SIZE); + } +} + +static void its_fini_core(void) +{ + if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) + its_pages_protect(&its_pages); + kfree(its_pages.pages); +} + #ifdef CONFIG_MODULES void its_init_mod(struct module *mod) { @@ -173,10 +206,8 @@ void its_fini_mod(struct module *mod) its_page = NULL; mutex_unlock(&text_mutex); - for (int i = 0; i < mod->arch.its_pages.num; i++) { - void *page = mod->arch.its_pages.pages[i]; - execmem_restore_rox(page, PAGE_SIZE); - } + if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) + its_pages_protect(&mod->arch.its_pages); } void its_free_mod(struct module *mod) @@ -194,28 +225,23 @@ void its_free_mod(struct module *mod) static void *its_alloc(void) { - void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); + struct its_array *pages = &its_pages; + void *page; +#ifdef CONFIG_MODULE + if (its_mod) + pages = &its_mod->arch.its_pages; +#endif + + page = __its_alloc(pages); if (!page) return NULL; -#ifdef CONFIG_MODULES - if (its_mod) { - struct its_array *pages = &its_mod->arch.its_pages; - void *tmp = krealloc(pages->pages, - (pages->num+1) * sizeof(void *), - GFP_KERNEL); - if (!tmp) - return NULL; + execmem_make_temp_rw(page, PAGE_SIZE); + if (pages == &its_pages) + set_memory_x((unsigned long)page, 1); - pages->pages = tmp; - pages->pages[pages->num++] = page; - - execmem_make_temp_rw(page, PAGE_SIZE); - } -#endif /* CONFIG_MODULES */ - - return no_free_ptr(page); + return page; } static void *its_allocate_thunk(int reg) @@ -269,7 +295,9 @@ u8 *its_static_thunk(int reg) return thunk; } -#endif +#else +static inline void its_fini_core(void) {} +#endif /* CONFIG_MITIGATION_ITS */ /* * Nomenclature for variable names to simplify and clarify this code and ease @@ -2339,6 +2367,8 @@ void __init alternative_instructions(void) apply_retpolines(__retpoline_sites, __retpoline_sites_end); apply_returns(__return_sites, __return_sites_end); + its_fini_core(); + /* * Adjust all CALL instructions to point to func()-10, including * those in .altinstr_replacement.

2 weeks, 2 days

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FAILED: patch "[PATCH] x86/its: explicitly manage permissions for ITS pages" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x a82b26451de126a5ae130361081986bc459afe9b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062013-chlorine-rubbing-22b0@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a82b26451de126a5ae130361081986bc459afe9b Mon Sep 17 00:00:00 2001 From: "Peter Zijlstra (Intel)" <peterz(a)infradead.org> Date: Tue, 3 Jun 2025 14:14:44 +0300 Subject: [PATCH] x86/its: explicitly manage permissions for ITS pages execmem_alloc() sets permissions differently depending on the kernel configuration, CPU support for PSE and whether a page is allocated before or after mark_rodata_ro(). Add tracking for pages allocated for ITS when patching the core kernel and make sure the permissions for ITS pages are explicitly managed for both kernel and module allocations. Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Co-developed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Reviewed-by: Nikolay Borisov <nik.borisov(a)suse.com> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-5-rppt@kernel.org diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index b50fe6ce4655..6455f7f751b3 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -116,6 +116,24 @@ static struct module *its_mod; #endif static void *its_page; static unsigned int its_offset; +struct its_array its_pages; + +static void *__its_alloc(struct its_array *pages) +{ + void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); + if (!page) + return NULL; + + void *tmp = krealloc(pages->pages, (pages->num+1) * sizeof(void *), + GFP_KERNEL); + if (!tmp) + return NULL; + + pages->pages = tmp; + pages->pages[pages->num++] = page; + + return no_free_ptr(page); +} /* Initialize a thunk with the "jmp *reg; int3" instructions. */ static void *its_init_thunk(void *thunk, int reg) @@ -151,6 +169,21 @@ static void *its_init_thunk(void *thunk, int reg) return thunk + offset; } +static void its_pages_protect(struct its_array *pages) +{ + for (int i = 0; i < pages->num; i++) { + void *page = pages->pages[i]; + execmem_restore_rox(page, PAGE_SIZE); + } +} + +static void its_fini_core(void) +{ + if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) + its_pages_protect(&its_pages); + kfree(its_pages.pages); +} + #ifdef CONFIG_MODULES void its_init_mod(struct module *mod) { @@ -173,10 +206,8 @@ void its_fini_mod(struct module *mod) its_page = NULL; mutex_unlock(&text_mutex); - for (int i = 0; i < mod->arch.its_pages.num; i++) { - void *page = mod->arch.its_pages.pages[i]; - execmem_restore_rox(page, PAGE_SIZE); - } + if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) + its_pages_protect(&mod->arch.its_pages); } void its_free_mod(struct module *mod) @@ -194,28 +225,23 @@ void its_free_mod(struct module *mod) static void *its_alloc(void) { - void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); + struct its_array *pages = &its_pages; + void *page; +#ifdef CONFIG_MODULE + if (its_mod) + pages = &its_mod->arch.its_pages; +#endif + + page = __its_alloc(pages); if (!page) return NULL; -#ifdef CONFIG_MODULES - if (its_mod) { - struct its_array *pages = &its_mod->arch.its_pages; - void *tmp = krealloc(pages->pages, - (pages->num+1) * sizeof(void *), - GFP_KERNEL); - if (!tmp) - return NULL; + execmem_make_temp_rw(page, PAGE_SIZE); + if (pages == &its_pages) + set_memory_x((unsigned long)page, 1); - pages->pages = tmp; - pages->pages[pages->num++] = page; - - execmem_make_temp_rw(page, PAGE_SIZE); - } -#endif /* CONFIG_MODULES */ - - return no_free_ptr(page); + return page; } static void *its_allocate_thunk(int reg) @@ -269,7 +295,9 @@ u8 *its_static_thunk(int reg) return thunk; } -#endif +#else +static inline void its_fini_core(void) {} +#endif /* CONFIG_MITIGATION_ITS */ /* * Nomenclature for variable names to simplify and clarify this code and ease @@ -2339,6 +2367,8 @@ void __init alternative_instructions(void) apply_retpolines(__retpoline_sites, __retpoline_sites_end); apply_returns(__return_sites, __return_sites_end); + its_fini_core(); + /* * Adjust all CALL instructions to point to func()-10, including * those in .altinstr_replacement.

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FAILED: patch "[PATCH] x86/its: explicitly manage permissions for ITS pages" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x a82b26451de126a5ae130361081986bc459afe9b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062013-banter-graveyard-ed28@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a82b26451de126a5ae130361081986bc459afe9b Mon Sep 17 00:00:00 2001 From: "Peter Zijlstra (Intel)" <peterz(a)infradead.org> Date: Tue, 3 Jun 2025 14:14:44 +0300 Subject: [PATCH] x86/its: explicitly manage permissions for ITS pages execmem_alloc() sets permissions differently depending on the kernel configuration, CPU support for PSE and whether a page is allocated before or after mark_rodata_ro(). Add tracking for pages allocated for ITS when patching the core kernel and make sure the permissions for ITS pages are explicitly managed for both kernel and module allocations. Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Co-developed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Reviewed-by: Nikolay Borisov <nik.borisov(a)suse.com> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-5-rppt@kernel.org diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index b50fe6ce4655..6455f7f751b3 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -116,6 +116,24 @@ static struct module *its_mod; #endif static void *its_page; static unsigned int its_offset; +struct its_array its_pages; + +static void *__its_alloc(struct its_array *pages) +{ + void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); + if (!page) + return NULL; + + void *tmp = krealloc(pages->pages, (pages->num+1) * sizeof(void *), + GFP_KERNEL); + if (!tmp) + return NULL; + + pages->pages = tmp; + pages->pages[pages->num++] = page; + + return no_free_ptr(page); +} /* Initialize a thunk with the "jmp *reg; int3" instructions. */ static void *its_init_thunk(void *thunk, int reg) @@ -151,6 +169,21 @@ static void *its_init_thunk(void *thunk, int reg) return thunk + offset; } +static void its_pages_protect(struct its_array *pages) +{ + for (int i = 0; i < pages->num; i++) { + void *page = pages->pages[i]; + execmem_restore_rox(page, PAGE_SIZE); + } +} + +static void its_fini_core(void) +{ + if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) + its_pages_protect(&its_pages); + kfree(its_pages.pages); +} + #ifdef CONFIG_MODULES void its_init_mod(struct module *mod) { @@ -173,10 +206,8 @@ void its_fini_mod(struct module *mod) its_page = NULL; mutex_unlock(&text_mutex); - for (int i = 0; i < mod->arch.its_pages.num; i++) { - void *page = mod->arch.its_pages.pages[i]; - execmem_restore_rox(page, PAGE_SIZE); - } + if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) + its_pages_protect(&mod->arch.its_pages); } void its_free_mod(struct module *mod) @@ -194,28 +225,23 @@ void its_free_mod(struct module *mod) static void *its_alloc(void) { - void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE); + struct its_array *pages = &its_pages; + void *page; +#ifdef CONFIG_MODULE + if (its_mod) + pages = &its_mod->arch.its_pages; +#endif + + page = __its_alloc(pages); if (!page) return NULL; -#ifdef CONFIG_MODULES - if (its_mod) { - struct its_array *pages = &its_mod->arch.its_pages; - void *tmp = krealloc(pages->pages, - (pages->num+1) * sizeof(void *), - GFP_KERNEL); - if (!tmp) - return NULL; + execmem_make_temp_rw(page, PAGE_SIZE); + if (pages == &its_pages) + set_memory_x((unsigned long)page, 1); - pages->pages = tmp; - pages->pages[pages->num++] = page; - - execmem_make_temp_rw(page, PAGE_SIZE); - } -#endif /* CONFIG_MODULES */ - - return no_free_ptr(page); + return page; } static void *its_allocate_thunk(int reg) @@ -269,7 +295,9 @@ u8 *its_static_thunk(int reg) return thunk; } -#endif +#else +static inline void its_fini_core(void) {} +#endif /* CONFIG_MITIGATION_ITS */ /* * Nomenclature for variable names to simplify and clarify this code and ease @@ -2339,6 +2367,8 @@ void __init alternative_instructions(void) apply_retpolines(__retpoline_sites, __retpoline_sites_end); apply_returns(__return_sites, __return_sites_end); + its_fini_core(); + /* * Adjust all CALL instructions to point to func()-10, including * those in .altinstr_replacement.

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FAILED: patch "[PATCH] x86/its: move its_pages array to struct mod_arch_specific" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 0b0cae7119a0ec9449d7261b5e672a5fed765068 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062001-charity-anytime-66e2@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0b0cae7119a0ec9449d7261b5e672a5fed765068 Mon Sep 17 00:00:00 2001 From: "Mike Rapoport (Microsoft)" <rppt(a)kernel.org> Date: Tue, 3 Jun 2025 14:14:43 +0300 Subject: [PATCH] x86/its: move its_pages array to struct mod_arch_specific The of pages with ITS thunks allocated for modules are tracked by an array in 'struct module'. Since this is very architecture specific data structure, move it to 'struct mod_arch_specific'. No functional changes. Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Suggested-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-4-rppt@kernel.org diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h index e988bac0a4a1..3c2de4ce3b10 100644 --- a/arch/x86/include/asm/module.h +++ b/arch/x86/include/asm/module.h @@ -5,12 +5,20 @@ #include <asm-generic/module.h> #include <asm/orc_types.h> +struct its_array { +#ifdef CONFIG_MITIGATION_ITS + void **pages; + int num; +#endif +}; + struct mod_arch_specific { #ifdef CONFIG_UNWINDER_ORC unsigned int num_orcs; int *orc_unwind_ip; struct orc_entry *orc_unwind; #endif + struct its_array its_pages; }; #endif /* _ASM_X86_MODULE_H */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index ecfe7b497cad..b50fe6ce4655 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -173,8 +173,8 @@ void its_fini_mod(struct module *mod) its_page = NULL; mutex_unlock(&text_mutex); - for (int i = 0; i < mod->its_num_pages; i++) { - void *page = mod->its_page_array[i]; + for (int i = 0; i < mod->arch.its_pages.num; i++) { + void *page = mod->arch.its_pages.pages[i]; execmem_restore_rox(page, PAGE_SIZE); } } @@ -184,11 +184,11 @@ void its_free_mod(struct module *mod) if (!cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS)) return; - for (int i = 0; i < mod->its_num_pages; i++) { - void *page = mod->its_page_array[i]; + for (int i = 0; i < mod->arch.its_pages.num; i++) { + void *page = mod->arch.its_pages.pages[i]; execmem_free(page); } - kfree(mod->its_page_array); + kfree(mod->arch.its_pages.pages); } #endif /* CONFIG_MODULES */ @@ -201,14 +201,15 @@ static void *its_alloc(void) #ifdef CONFIG_MODULES if (its_mod) { - void *tmp = krealloc(its_mod->its_page_array, - (its_mod->its_num_pages+1) * sizeof(void *), + struct its_array *pages = &its_mod->arch.its_pages; + void *tmp = krealloc(pages->pages, + (pages->num+1) * sizeof(void *), GFP_KERNEL); if (!tmp) return NULL; - its_mod->its_page_array = tmp; - its_mod->its_page_array[its_mod->its_num_pages++] = page; + pages->pages = tmp; + pages->pages[pages->num++] = page; execmem_make_temp_rw(page, PAGE_SIZE); } diff --git a/include/linux/module.h b/include/linux/module.h index 92e1420fccdf..5faa1fb1f4b4 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -586,11 +586,6 @@ struct module { atomic_t refcnt; #endif -#ifdef CONFIG_MITIGATION_ITS - int its_num_pages; - void **its_page_array; -#endif - #ifdef CONFIG_CONSTRUCTORS /* Constructor functions. */ ctor_fn_t *ctors;

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FAILED: patch "[PATCH] x86/its: move its_pages array to struct mod_arch_specific" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 0b0cae7119a0ec9449d7261b5e672a5fed765068 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062000-reveal-jury-be96@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0b0cae7119a0ec9449d7261b5e672a5fed765068 Mon Sep 17 00:00:00 2001 From: "Mike Rapoport (Microsoft)" <rppt(a)kernel.org> Date: Tue, 3 Jun 2025 14:14:43 +0300 Subject: [PATCH] x86/its: move its_pages array to struct mod_arch_specific The of pages with ITS thunks allocated for modules are tracked by an array in 'struct module'. Since this is very architecture specific data structure, move it to 'struct mod_arch_specific'. No functional changes. Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Suggested-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-4-rppt@kernel.org diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h index e988bac0a4a1..3c2de4ce3b10 100644 --- a/arch/x86/include/asm/module.h +++ b/arch/x86/include/asm/module.h @@ -5,12 +5,20 @@ #include <asm-generic/module.h> #include <asm/orc_types.h> +struct its_array { +#ifdef CONFIG_MITIGATION_ITS + void **pages; + int num; +#endif +}; + struct mod_arch_specific { #ifdef CONFIG_UNWINDER_ORC unsigned int num_orcs; int *orc_unwind_ip; struct orc_entry *orc_unwind; #endif + struct its_array its_pages; }; #endif /* _ASM_X86_MODULE_H */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index ecfe7b497cad..b50fe6ce4655 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -173,8 +173,8 @@ void its_fini_mod(struct module *mod) its_page = NULL; mutex_unlock(&text_mutex); - for (int i = 0; i < mod->its_num_pages; i++) { - void *page = mod->its_page_array[i]; + for (int i = 0; i < mod->arch.its_pages.num; i++) { + void *page = mod->arch.its_pages.pages[i]; execmem_restore_rox(page, PAGE_SIZE); } } @@ -184,11 +184,11 @@ void its_free_mod(struct module *mod) if (!cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS)) return; - for (int i = 0; i < mod->its_num_pages; i++) { - void *page = mod->its_page_array[i]; + for (int i = 0; i < mod->arch.its_pages.num; i++) { + void *page = mod->arch.its_pages.pages[i]; execmem_free(page); } - kfree(mod->its_page_array); + kfree(mod->arch.its_pages.pages); } #endif /* CONFIG_MODULES */ @@ -201,14 +201,15 @@ static void *its_alloc(void) #ifdef CONFIG_MODULES if (its_mod) { - void *tmp = krealloc(its_mod->its_page_array, - (its_mod->its_num_pages+1) * sizeof(void *), + struct its_array *pages = &its_mod->arch.its_pages; + void *tmp = krealloc(pages->pages, + (pages->num+1) * sizeof(void *), GFP_KERNEL); if (!tmp) return NULL; - its_mod->its_page_array = tmp; - its_mod->its_page_array[its_mod->its_num_pages++] = page; + pages->pages = tmp; + pages->pages[pages->num++] = page; execmem_make_temp_rw(page, PAGE_SIZE); } diff --git a/include/linux/module.h b/include/linux/module.h index 92e1420fccdf..5faa1fb1f4b4 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -586,11 +586,6 @@ struct module { atomic_t refcnt; #endif -#ifdef CONFIG_MITIGATION_ITS - int its_num_pages; - void **its_page_array; -#endif - #ifdef CONFIG_CONSTRUCTORS /* Constructor functions. */ ctor_fn_t *ctors;

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FAILED: patch "[PATCH] x86/its: move its_pages array to struct mod_arch_specific" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 0b0cae7119a0ec9449d7261b5e672a5fed765068 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062000-untold-childhood-3862@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0b0cae7119a0ec9449d7261b5e672a5fed765068 Mon Sep 17 00:00:00 2001 From: "Mike Rapoport (Microsoft)" <rppt(a)kernel.org> Date: Tue, 3 Jun 2025 14:14:43 +0300 Subject: [PATCH] x86/its: move its_pages array to struct mod_arch_specific The of pages with ITS thunks allocated for modules are tracked by an array in 'struct module'. Since this is very architecture specific data structure, move it to 'struct mod_arch_specific'. No functional changes. Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Suggested-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-4-rppt@kernel.org diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h index e988bac0a4a1..3c2de4ce3b10 100644 --- a/arch/x86/include/asm/module.h +++ b/arch/x86/include/asm/module.h @@ -5,12 +5,20 @@ #include <asm-generic/module.h> #include <asm/orc_types.h> +struct its_array { +#ifdef CONFIG_MITIGATION_ITS + void **pages; + int num; +#endif +}; + struct mod_arch_specific { #ifdef CONFIG_UNWINDER_ORC unsigned int num_orcs; int *orc_unwind_ip; struct orc_entry *orc_unwind; #endif + struct its_array its_pages; }; #endif /* _ASM_X86_MODULE_H */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index ecfe7b497cad..b50fe6ce4655 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -173,8 +173,8 @@ void its_fini_mod(struct module *mod) its_page = NULL; mutex_unlock(&text_mutex); - for (int i = 0; i < mod->its_num_pages; i++) { - void *page = mod->its_page_array[i]; + for (int i = 0; i < mod->arch.its_pages.num; i++) { + void *page = mod->arch.its_pages.pages[i]; execmem_restore_rox(page, PAGE_SIZE); } } @@ -184,11 +184,11 @@ void its_free_mod(struct module *mod) if (!cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS)) return; - for (int i = 0; i < mod->its_num_pages; i++) { - void *page = mod->its_page_array[i]; + for (int i = 0; i < mod->arch.its_pages.num; i++) { + void *page = mod->arch.its_pages.pages[i]; execmem_free(page); } - kfree(mod->its_page_array); + kfree(mod->arch.its_pages.pages); } #endif /* CONFIG_MODULES */ @@ -201,14 +201,15 @@ static void *its_alloc(void) #ifdef CONFIG_MODULES if (its_mod) { - void *tmp = krealloc(its_mod->its_page_array, - (its_mod->its_num_pages+1) * sizeof(void *), + struct its_array *pages = &its_mod->arch.its_pages; + void *tmp = krealloc(pages->pages, + (pages->num+1) * sizeof(void *), GFP_KERNEL); if (!tmp) return NULL; - its_mod->its_page_array = tmp; - its_mod->its_page_array[its_mod->its_num_pages++] = page; + pages->pages = tmp; + pages->pages[pages->num++] = page; execmem_make_temp_rw(page, PAGE_SIZE); } diff --git a/include/linux/module.h b/include/linux/module.h index 92e1420fccdf..5faa1fb1f4b4 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -586,11 +586,6 @@ struct module { atomic_t refcnt; #endif -#ifdef CONFIG_MITIGATION_ITS - int its_num_pages; - void **its_page_array; -#endif - #ifdef CONFIG_CONSTRUCTORS /* Constructor functions. */ ctor_fn_t *ctors;

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FAILED: patch "[PATCH] x86/its: move its_pages array to struct mod_arch_specific" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 0b0cae7119a0ec9449d7261b5e672a5fed765068 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062059-map-powdering-0ee4@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0b0cae7119a0ec9449d7261b5e672a5fed765068 Mon Sep 17 00:00:00 2001 From: "Mike Rapoport (Microsoft)" <rppt(a)kernel.org> Date: Tue, 3 Jun 2025 14:14:43 +0300 Subject: [PATCH] x86/its: move its_pages array to struct mod_arch_specific The of pages with ITS thunks allocated for modules are tracked by an array in 'struct module'. Since this is very architecture specific data structure, move it to 'struct mod_arch_specific'. No functional changes. Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches") Suggested-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/20250603111446.2609381-4-rppt@kernel.org diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h index e988bac0a4a1..3c2de4ce3b10 100644 --- a/arch/x86/include/asm/module.h +++ b/arch/x86/include/asm/module.h @@ -5,12 +5,20 @@ #include <asm-generic/module.h> #include <asm/orc_types.h> +struct its_array { +#ifdef CONFIG_MITIGATION_ITS + void **pages; + int num; +#endif +}; + struct mod_arch_specific { #ifdef CONFIG_UNWINDER_ORC unsigned int num_orcs; int *orc_unwind_ip; struct orc_entry *orc_unwind; #endif + struct its_array its_pages; }; #endif /* _ASM_X86_MODULE_H */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index ecfe7b497cad..b50fe6ce4655 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -173,8 +173,8 @@ void its_fini_mod(struct module *mod) its_page = NULL; mutex_unlock(&text_mutex); - for (int i = 0; i < mod->its_num_pages; i++) { - void *page = mod->its_page_array[i]; + for (int i = 0; i < mod->arch.its_pages.num; i++) { + void *page = mod->arch.its_pages.pages[i]; execmem_restore_rox(page, PAGE_SIZE); } } @@ -184,11 +184,11 @@ void its_free_mod(struct module *mod) if (!cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS)) return; - for (int i = 0; i < mod->its_num_pages; i++) { - void *page = mod->its_page_array[i]; + for (int i = 0; i < mod->arch.its_pages.num; i++) { + void *page = mod->arch.its_pages.pages[i]; execmem_free(page); } - kfree(mod->its_page_array); + kfree(mod->arch.its_pages.pages); } #endif /* CONFIG_MODULES */ @@ -201,14 +201,15 @@ static void *its_alloc(void) #ifdef CONFIG_MODULES if (its_mod) { - void *tmp = krealloc(its_mod->its_page_array, - (its_mod->its_num_pages+1) * sizeof(void *), + struct its_array *pages = &its_mod->arch.its_pages; + void *tmp = krealloc(pages->pages, + (pages->num+1) * sizeof(void *), GFP_KERNEL); if (!tmp) return NULL; - its_mod->its_page_array = tmp; - its_mod->its_page_array[its_mod->its_num_pages++] = page; + pages->pages = tmp; + pages->pages[pages->num++] = page; execmem_make_temp_rw(page, PAGE_SIZE); } diff --git a/include/linux/module.h b/include/linux/module.h index 92e1420fccdf..5faa1fb1f4b4 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -586,11 +586,6 @@ struct module { atomic_t refcnt; #endif -#ifdef CONFIG_MITIGATION_ITS - int its_num_pages; - void **its_page_array; -#endif - #ifdef CONFIG_CONSTRUCTORS /* Constructor functions. */ ctor_fn_t *ctors;

2 weeks, 2 days

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FAILED: patch "[PATCH] mm: close theoretical race where stale TLB entries could" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 383c4613c67c26e90e8eebb72e3083457d02033f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062029-saturday-conical-0eae@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 383c4613c67c26e90e8eebb72e3083457d02033f Mon Sep 17 00:00:00 2001 From: Ryan Roberts <ryan.roberts(a)arm.com> Date: Fri, 6 Jun 2025 10:28:07 +0100 Subject: [PATCH] mm: close theoretical race where stale TLB entries could linger Commit 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") described a theoretical race as such: """ Nadav Amit identified a theoretical race between page reclaim and mprotect due to TLB flushes being batched outside of the PTL being held. He described the race as follows: CPU0 CPU1 ---- ---- user accesses memory using RW PTE [PTE now cached in TLB] try_to_unmap_one() ==> ptep_get_and_clear() ==> set_tlb_ubc_flush_pending() mprotect(addr, PROT_READ) ==> change_pte_range() ==> [ PTE non-present - no flush ] user writes using cached RW PTE ... try_to_unmap_flush() The same type of race exists for reads when protecting for PROT_NONE and also exists for operations that can leave an old TLB entry behind such as munmap, mremap and madvise. """ The solution was to introduce flush_tlb_batched_pending() and call it under the PTL from mprotect/madvise/munmap/mremap to complete any pending tlb flushes. However, while madvise_free_pte_range() and madvise_cold_or_pageout_pte_range() were both retro-fitted to call flush_tlb_batched_pending() immediately after initially acquiring the PTL, they both temporarily release the PTL to split a large folio if they stumble upon one. In this case, where re-acquiring the PTL flush_tlb_batched_pending() must be called again, but it previously was not. Let's fix that. There are 2 Fixes: tags here: the first is the commit that fixed madvise_free_pte_range(). The second is the commit that added madvise_cold_or_pageout_pte_range(), which looks like it copy/pasted the faulty pattern from madvise_free_pte_range(). This is a theoretical bug discovered during code review. Link: https://lkml.kernel.org/r/20250606092809.4194056-1-ryan.roberts@arm.com Fixes: 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD") Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> Reviewed-by: Jann Horn <jannh(a)google.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Mel Gorman <mgorman <mgorman(a)suse.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/madvise.c b/mm/madvise.c index 5f7a66a1617e..1d44a35ae85c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -508,6 +508,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, pte_offset_map_lock(mm, pmd, addr, &ptl); if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0; @@ -741,6 +742,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, start_pte = pte; if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0;

2 weeks, 2 days

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FAILED: patch "[PATCH] mm: close theoretical race where stale TLB entries could" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 383c4613c67c26e90e8eebb72e3083457d02033f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062028-richly-basket-a70f@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 383c4613c67c26e90e8eebb72e3083457d02033f Mon Sep 17 00:00:00 2001 From: Ryan Roberts <ryan.roberts(a)arm.com> Date: Fri, 6 Jun 2025 10:28:07 +0100 Subject: [PATCH] mm: close theoretical race where stale TLB entries could linger Commit 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") described a theoretical race as such: """ Nadav Amit identified a theoretical race between page reclaim and mprotect due to TLB flushes being batched outside of the PTL being held. He described the race as follows: CPU0 CPU1 ---- ---- user accesses memory using RW PTE [PTE now cached in TLB] try_to_unmap_one() ==> ptep_get_and_clear() ==> set_tlb_ubc_flush_pending() mprotect(addr, PROT_READ) ==> change_pte_range() ==> [ PTE non-present - no flush ] user writes using cached RW PTE ... try_to_unmap_flush() The same type of race exists for reads when protecting for PROT_NONE and also exists for operations that can leave an old TLB entry behind such as munmap, mremap and madvise. """ The solution was to introduce flush_tlb_batched_pending() and call it under the PTL from mprotect/madvise/munmap/mremap to complete any pending tlb flushes. However, while madvise_free_pte_range() and madvise_cold_or_pageout_pte_range() were both retro-fitted to call flush_tlb_batched_pending() immediately after initially acquiring the PTL, they both temporarily release the PTL to split a large folio if they stumble upon one. In this case, where re-acquiring the PTL flush_tlb_batched_pending() must be called again, but it previously was not. Let's fix that. There are 2 Fixes: tags here: the first is the commit that fixed madvise_free_pte_range(). The second is the commit that added madvise_cold_or_pageout_pte_range(), which looks like it copy/pasted the faulty pattern from madvise_free_pte_range(). This is a theoretical bug discovered during code review. Link: https://lkml.kernel.org/r/20250606092809.4194056-1-ryan.roberts@arm.com Fixes: 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD") Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> Reviewed-by: Jann Horn <jannh(a)google.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Mel Gorman <mgorman <mgorman(a)suse.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/madvise.c b/mm/madvise.c index 5f7a66a1617e..1d44a35ae85c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -508,6 +508,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, pte_offset_map_lock(mm, pmd, addr, &ptl); if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0; @@ -741,6 +742,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, start_pte = pte; if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0;

2 weeks, 2 days

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FAILED: patch "[PATCH] mm: close theoretical race where stale TLB entries could" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 383c4613c67c26e90e8eebb72e3083457d02033f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062027-tapestry-uptake-5f29@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 383c4613c67c26e90e8eebb72e3083457d02033f Mon Sep 17 00:00:00 2001 From: Ryan Roberts <ryan.roberts(a)arm.com> Date: Fri, 6 Jun 2025 10:28:07 +0100 Subject: [PATCH] mm: close theoretical race where stale TLB entries could linger Commit 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") described a theoretical race as such: """ Nadav Amit identified a theoretical race between page reclaim and mprotect due to TLB flushes being batched outside of the PTL being held. He described the race as follows: CPU0 CPU1 ---- ---- user accesses memory using RW PTE [PTE now cached in TLB] try_to_unmap_one() ==> ptep_get_and_clear() ==> set_tlb_ubc_flush_pending() mprotect(addr, PROT_READ) ==> change_pte_range() ==> [ PTE non-present - no flush ] user writes using cached RW PTE ... try_to_unmap_flush() The same type of race exists for reads when protecting for PROT_NONE and also exists for operations that can leave an old TLB entry behind such as munmap, mremap and madvise. """ The solution was to introduce flush_tlb_batched_pending() and call it under the PTL from mprotect/madvise/munmap/mremap to complete any pending tlb flushes. However, while madvise_free_pte_range() and madvise_cold_or_pageout_pte_range() were both retro-fitted to call flush_tlb_batched_pending() immediately after initially acquiring the PTL, they both temporarily release the PTL to split a large folio if they stumble upon one. In this case, where re-acquiring the PTL flush_tlb_batched_pending() must be called again, but it previously was not. Let's fix that. There are 2 Fixes: tags here: the first is the commit that fixed madvise_free_pte_range(). The second is the commit that added madvise_cold_or_pageout_pte_range(), which looks like it copy/pasted the faulty pattern from madvise_free_pte_range(). This is a theoretical bug discovered during code review. Link: https://lkml.kernel.org/r/20250606092809.4194056-1-ryan.roberts@arm.com Fixes: 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD") Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> Reviewed-by: Jann Horn <jannh(a)google.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Mel Gorman <mgorman <mgorman(a)suse.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/madvise.c b/mm/madvise.c index 5f7a66a1617e..1d44a35ae85c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -508,6 +508,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, pte_offset_map_lock(mm, pmd, addr, &ptl); if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0; @@ -741,6 +742,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, start_pte = pte; if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0;

2 weeks, 2 days

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FAILED: patch "[PATCH] mm: close theoretical race where stale TLB entries could" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 383c4613c67c26e90e8eebb72e3083457d02033f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062026-shrewdly-trough-b30e@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 383c4613c67c26e90e8eebb72e3083457d02033f Mon Sep 17 00:00:00 2001 From: Ryan Roberts <ryan.roberts(a)arm.com> Date: Fri, 6 Jun 2025 10:28:07 +0100 Subject: [PATCH] mm: close theoretical race where stale TLB entries could linger Commit 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") described a theoretical race as such: """ Nadav Amit identified a theoretical race between page reclaim and mprotect due to TLB flushes being batched outside of the PTL being held. He described the race as follows: CPU0 CPU1 ---- ---- user accesses memory using RW PTE [PTE now cached in TLB] try_to_unmap_one() ==> ptep_get_and_clear() ==> set_tlb_ubc_flush_pending() mprotect(addr, PROT_READ) ==> change_pte_range() ==> [ PTE non-present - no flush ] user writes using cached RW PTE ... try_to_unmap_flush() The same type of race exists for reads when protecting for PROT_NONE and also exists for operations that can leave an old TLB entry behind such as munmap, mremap and madvise. """ The solution was to introduce flush_tlb_batched_pending() and call it under the PTL from mprotect/madvise/munmap/mremap to complete any pending tlb flushes. However, while madvise_free_pte_range() and madvise_cold_or_pageout_pte_range() were both retro-fitted to call flush_tlb_batched_pending() immediately after initially acquiring the PTL, they both temporarily release the PTL to split a large folio if they stumble upon one. In this case, where re-acquiring the PTL flush_tlb_batched_pending() must be called again, but it previously was not. Let's fix that. There are 2 Fixes: tags here: the first is the commit that fixed madvise_free_pte_range(). The second is the commit that added madvise_cold_or_pageout_pte_range(), which looks like it copy/pasted the faulty pattern from madvise_free_pte_range(). This is a theoretical bug discovered during code review. Link: https://lkml.kernel.org/r/20250606092809.4194056-1-ryan.roberts@arm.com Fixes: 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD") Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> Reviewed-by: Jann Horn <jannh(a)google.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Mel Gorman <mgorman <mgorman(a)suse.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/madvise.c b/mm/madvise.c index 5f7a66a1617e..1d44a35ae85c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -508,6 +508,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, pte_offset_map_lock(mm, pmd, addr, &ptl); if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0; @@ -741,6 +742,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, start_pte = pte; if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0;

2 weeks, 2 days

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FAILED: patch "[PATCH] mm: close theoretical race where stale TLB entries could" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 383c4613c67c26e90e8eebb72e3083457d02033f # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062025-boogieman-flyable-ee70@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 383c4613c67c26e90e8eebb72e3083457d02033f Mon Sep 17 00:00:00 2001 From: Ryan Roberts <ryan.roberts(a)arm.com> Date: Fri, 6 Jun 2025 10:28:07 +0100 Subject: [PATCH] mm: close theoretical race where stale TLB entries could linger Commit 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") described a theoretical race as such: """ Nadav Amit identified a theoretical race between page reclaim and mprotect due to TLB flushes being batched outside of the PTL being held. He described the race as follows: CPU0 CPU1 ---- ---- user accesses memory using RW PTE [PTE now cached in TLB] try_to_unmap_one() ==> ptep_get_and_clear() ==> set_tlb_ubc_flush_pending() mprotect(addr, PROT_READ) ==> change_pte_range() ==> [ PTE non-present - no flush ] user writes using cached RW PTE ... try_to_unmap_flush() The same type of race exists for reads when protecting for PROT_NONE and also exists for operations that can leave an old TLB entry behind such as munmap, mremap and madvise. """ The solution was to introduce flush_tlb_batched_pending() and call it under the PTL from mprotect/madvise/munmap/mremap to complete any pending tlb flushes. However, while madvise_free_pte_range() and madvise_cold_or_pageout_pte_range() were both retro-fitted to call flush_tlb_batched_pending() immediately after initially acquiring the PTL, they both temporarily release the PTL to split a large folio if they stumble upon one. In this case, where re-acquiring the PTL flush_tlb_batched_pending() must be called again, but it previously was not. Let's fix that. There are 2 Fixes: tags here: the first is the commit that fixed madvise_free_pte_range(). The second is the commit that added madvise_cold_or_pageout_pte_range(), which looks like it copy/pasted the faulty pattern from madvise_free_pte_range(). This is a theoretical bug discovered during code review. Link: https://lkml.kernel.org/r/20250606092809.4194056-1-ryan.roberts@arm.com Fixes: 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD") Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> Reviewed-by: Jann Horn <jannh(a)google.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Mel Gorman <mgorman <mgorman(a)suse.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/madvise.c b/mm/madvise.c index 5f7a66a1617e..1d44a35ae85c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -508,6 +508,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, pte_offset_map_lock(mm, pmd, addr, &ptl); if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0; @@ -741,6 +742,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, start_pte = pte; if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0;

2 weeks, 2 days

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FAILED: patch "[PATCH] net_sched: sch_sfq: reject invalid perturb period" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 7ca52541c05c832d32b112274f81a985101f9ba8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062026-excitable-trunks-92e6@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7ca52541c05c832d32b112274f81a985101f9ba8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet(a)google.com> Date: Wed, 11 Jun 2025 08:35:01 +0000 Subject: [PATCH] net_sched: sch_sfq: reject invalid perturb period Gerrard Tai reported that SFQ perturb_period has no range check yet, and this can be used to trigger a race condition fixed in a separate patch. We want to make sure ctl->perturb_period * HZ will not overflow and is positive. Tested: tc qd add dev lo root sfq perturb -10 # negative value : error Error: sch_sfq: invalid perturb period. tc qd add dev lo root sfq perturb 1000000000 # too big : error Error: sch_sfq: invalid perturb period. tc qd add dev lo root sfq perturb 2000000 # acceptable value tc -s -d qd sh dev lo qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Gerrard Tai <gerrard.tai(a)starlabs.sg> Signed-off-by: Eric Dumazet <edumazet(a)google.com> Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20250611083501.1810459-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c index 77fa02f2bfcd..a8cca549b5a2 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -656,6 +656,14 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt, NL_SET_ERR_MSG_MOD(extack, "invalid quantum"); return -EINVAL; } + + if (ctl->perturb_period < 0 || + ctl->perturb_period > INT_MAX / HZ) { + NL_SET_ERR_MSG_MOD(extack, "invalid perturb period"); + return -EINVAL; + } + perturb_period = ctl->perturb_period * HZ; + if (ctl_v1 && !red_check_params(ctl_v1->qth_min, ctl_v1->qth_max, ctl_v1->Wlog, ctl_v1->Scell_log, NULL)) return -EINVAL; @@ -672,14 +680,12 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt, headdrop = q->headdrop; maxdepth = q->maxdepth; maxflows = q->maxflows; - perturb_period = q->perturb_period; quantum = q->quantum; flags = q->flags; /* update and validate configuration */ if (ctl->quantum) quantum = ctl->quantum; - perturb_period = ctl->perturb_period * HZ; if (ctl->flows) maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS); if (ctl->divisor) {

2 weeks, 2 days

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FAILED: patch "[PATCH] net_sched: sch_sfq: reject invalid perturb period" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 7ca52541c05c832d32b112274f81a985101f9ba8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062026-stinger-coeditor-bb58@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7ca52541c05c832d32b112274f81a985101f9ba8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet(a)google.com> Date: Wed, 11 Jun 2025 08:35:01 +0000 Subject: [PATCH] net_sched: sch_sfq: reject invalid perturb period Gerrard Tai reported that SFQ perturb_period has no range check yet, and this can be used to trigger a race condition fixed in a separate patch. We want to make sure ctl->perturb_period * HZ will not overflow and is positive. Tested: tc qd add dev lo root sfq perturb -10 # negative value : error Error: sch_sfq: invalid perturb period. tc qd add dev lo root sfq perturb 1000000000 # too big : error Error: sch_sfq: invalid perturb period. tc qd add dev lo root sfq perturb 2000000 # acceptable value tc -s -d qd sh dev lo qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Gerrard Tai <gerrard.tai(a)starlabs.sg> Signed-off-by: Eric Dumazet <edumazet(a)google.com> Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20250611083501.1810459-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c index 77fa02f2bfcd..a8cca549b5a2 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -656,6 +656,14 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt, NL_SET_ERR_MSG_MOD(extack, "invalid quantum"); return -EINVAL; } + + if (ctl->perturb_period < 0 || + ctl->perturb_period > INT_MAX / HZ) { + NL_SET_ERR_MSG_MOD(extack, "invalid perturb period"); + return -EINVAL; + } + perturb_period = ctl->perturb_period * HZ; + if (ctl_v1 && !red_check_params(ctl_v1->qth_min, ctl_v1->qth_max, ctl_v1->Wlog, ctl_v1->Scell_log, NULL)) return -EINVAL; @@ -672,14 +680,12 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt, headdrop = q->headdrop; maxdepth = q->maxdepth; maxflows = q->maxflows; - perturb_period = q->perturb_period; quantum = q->quantum; flags = q->flags; /* update and validate configuration */ if (ctl->quantum) quantum = ctl->quantum; - perturb_period = ctl->perturb_period * HZ; if (ctl->flows) maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS); if (ctl->divisor) {

2 weeks, 2 days

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FAILED: patch "[PATCH] cifs: deal with the channel loading lag while picking" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 66d590b828b1fd9fa337047ae58fe1c4c6f43609 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062054-luminance-hacker-c550@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 66d590b828b1fd9fa337047ae58fe1c4c6f43609 Mon Sep 17 00:00:00 2001 From: Shyam Prasad N <sprasad(a)microsoft.com> Date: Mon, 2 Jun 2025 22:37:12 +0530 Subject: [PATCH] cifs: deal with the channel loading lag while picking channels Our current approach to select a channel for sending requests is this: 1. iterate all channels to find the min and max queue depth 2. if min and max are not the same, pick the channel with min depth 3. if min and max are same, round robin, as all channels are equally loaded The problem with this approach is that there's a lag between selecting a channel and sending the request (that increases the queue depth on the channel). While these numbers will eventually catch up, there could be a skew in the channel usage, depending on the application's I/O parallelism and the server's speed of handling requests. With sufficient parallelism, this lag can artificially increase the queue depth, thereby impacting the performance negatively. This change will change the step 1 above to start the iteration from the last selected channel. This is to reduce the skew in channel usage even in the presence of this lag. Fixes: ea90708d3cf3 ("cifs: use the least loaded channel for sending requests") Cc: <stable(a)vger.kernel.org> Signed-off-by: Shyam Prasad N <sprasad(a)microsoft.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/transport.c b/fs/smb/client/transport.c index 266af17aa7d9..191783f553ce 100644 --- a/fs/smb/client/transport.c +++ b/fs/smb/client/transport.c @@ -1018,14 +1018,16 @@ struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses) uint index = 0; unsigned int min_in_flight = UINT_MAX, max_in_flight = 0; struct TCP_Server_Info *server = NULL; - int i; + int i, start, cur; if (!ses) return NULL; spin_lock(&ses->chan_lock); + start = atomic_inc_return(&ses->chan_seq); for (i = 0; i < ses->chan_count; i++) { - server = ses->chans[i].server; + cur = (start + i) % ses->chan_count; + server = ses->chans[cur].server; if (!server || server->terminate) continue; @@ -1042,17 +1044,15 @@ struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses) */ if (server->in_flight < min_in_flight) { min_in_flight = server->in_flight; - index = i; + index = cur; } if (server->in_flight > max_in_flight) max_in_flight = server->in_flight; } /* if all channels are equally loaded, fall back to round-robin */ - if (min_in_flight == max_in_flight) { - index = (uint)atomic_inc_return(&ses->chan_seq); - index %= ses->chan_count; - } + if (min_in_flight == max_in_flight) + index = (uint)start % ses->chan_count; server = ses->chans[index].server; spin_unlock(&ses->chan_lock);

2 weeks, 2 days

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[REGRESSION] drm/amd/display: Radeon 840M/860M: bisected suspend crash

by ggo＠tuxedocomputers.com

Hi, I have discovered that two small form factor desktops with Ryzen AI 7 350 and Ryzen AI 5 340 crash when woken up from suspend. I can see how the LED on the USB mouse is switched on when I trigger a resume via keyboard button, but the display remains black. The kernel also no longer responds to Magic SysRq keys in this state. The problem affects all kernels after merge b50753547453 (v6.11.0). But this merge only adds PCI_DEVICE_ID_AMD_1AH_M60H_ROOT with commit 59c34008d (necessary to trigger this bug with Ryzen AI CPU). I cherry-picked this commit and continued searching. Which finally led me to commit f6098641d3e - drm/amd/display: fix s2idle entry for DCN3.5+ If I remove the code, which has changed somewhat in the meantime, then the suspend works without any problems. See the following patch. Regards, Georg diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index d3100f641ac6..76204ae70acc 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -3121,9 +3121,6 @@ static int dm_suspend(struct amdgpu_ip_block *ip_block) dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D3); - if (dm->dc->caps.ips_support && adev->in_s0ix) - dc_allow_idle_optimizations(dm->dc, true); - dc_dmub_srv_set_power_state(dm->dc->ctx->dmub_srv, DC_ACPI_CM_POWER_STATE_D3); return 0;

2 weeks, 2 days

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[PATCH v9 1/4] serial: 8250: fix panic due to PSLVERR

by Yunhui Cui

When the PSLVERR_RESP_EN parameter is set to 1, the device generates an error response if an attempt is made to read an empty RBR (Receive Buffer Register) while the FIFO is enabled. In serial8250_do_startup(), calling serial_port_out(port, UART_LCR, UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter function enables the FIFO via serial_out(p, UART_FCR, p->fcr). Execution proceeds to the serial_port_in(port, UART_RX). This satisfies the PSLVERR trigger condition. When another CPU (e.g., using printk()) is accessing the UART (UART is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter dw8250_force_idle(). Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock to fix this issue. Panic backtrace: [ 0.442336] Oops - unknown exception [#1] [ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a [ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e ... [ 0.442416] console_on_rootfs+0x26/0x70 Fixes: c49436b657d0 ("serial: 8250_dw: Improve unwritable LCR workaround") Link: https://lore.kernel.org/all/84cydt5peu.fsf@jogness.linutronix.de/T/ Signed-off-by: Yunhui Cui <cuiyunhui(a)bytedance.com> Cc: stable(a)vger.kernel.org --- drivers/tty/serial/8250/8250_port.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 6d7b8c4667c9c..07fe818dffa34 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -2376,9 +2376,10 @@ int serial8250_do_startup(struct uart_port *port) /* * Now, initialize the UART */ - serial_port_out(port, UART_LCR, UART_LCR_WLEN8); uart_port_lock_irqsave(port, &flags); + serial_port_out(port, UART_LCR, UART_LCR_WLEN8); + if (up->port.flags & UPF_FOURPORT) { if (!up->port.irq) up->port.mctrl |= TIOCM_OUT1; -- 2.39.5

2 weeks, 2 days

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Re: [PATCH net-next v9 2/2] page_pool: Track DMA-mapped pages and unmap them when destroying the pool

by Jakub Kicinski

On Fri, 13 Jun 2025 10:41:10 +0200 Toke Høiland-Jørgensen wrote: > Jakub Kicinski <kuba(a)kernel.org> writes: > > > On Thu, 12 Jun 2025 09:25:30 +0200 Toke Høiland-Jørgensen wrote: > >> Hmm, okay, guess we should ask Sasha to drop these, then? > >> > >> https://lore.kernel.org/r/20250610122811.1567780-1-sashal@kernel.org > >> https://lore.kernel.org/r/20250610120306.1543986-1-sashal@kernel.org > > > > These links don't work for me? > > Oh, sorry, didn't realise the stable notifications are not archived on > lore. Here are the patches in the stable queue: > > https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tre… > https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tre… > https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tre… > https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tre… Thanks! Sasha, could we drop these please? They need more mileage before we send them to LTS.

2 weeks, 3 days

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FAILED: patch "[PATCH] mm/khugepaged: fix race with folio split/free using temporary" failed to apply to 6.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.15.y git checkout FETCH_HEAD git cherry-pick -x 595cf683519ab5a277d258a2251ee8cc7b838d6d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062039-policy-handheld-01c6@gregkh' --subject-prefix 'PATCH 6.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 595cf683519ab5a277d258a2251ee8cc7b838d6d Mon Sep 17 00:00:00 2001 From: Shivank Garg <shivankg(a)amd.com> Date: Mon, 26 May 2025 18:28:18 +0000 Subject: [PATCH] mm/khugepaged: fix race with folio split/free using temporary reference hpage_collapse_scan_file() calls is_refcount_suitable(), which in turn calls folio_mapcount(). folio_mapcount() checks folio_test_large() before proceeding to folio_large_mapcount(), but there is a race window where the folio may get split/freed between these checks, triggering: VM_WARN_ON_FOLIO(!folio_test_large(folio), folio) Take a temporary reference to the folio in hpage_collapse_scan_file(). This stabilizes the folio during refcount check and prevents incorrect large folio detection due to concurrent split/free. Use helper folio_expected_ref_count() + 1 to compare with folio_ref_count() instead of using is_refcount_suitable(). Link: https://lkml.kernel.org/r/20250526182818.37978-1-shivankg@amd.com Fixes: 05c5323b2a34 ("mm: track mapcount of large folios in single value") Signed-off-by: Shivank Garg <shivankg(a)amd.com> Reported-by: syzbot+2b99589e33edbe9475ca(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6828470d.a70a0220.38f255.000c.GAE@google.com Suggested-by: David Hildenbrand <david(a)redhat.com> Acked-by: David Hildenbrand <david(a)redhat.com> Acked-by: Dev Jain <dev.jain(a)arm.com> Reviewed-by: Baolin Wang <baolin.wang(a)linux.alibaba.com> Cc: Bharata B Rao <bharata(a)amd.com> Cc: Fengwei Yin <fengwei.yin(a)intel.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Mariano Pache <npache(a)redhat.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Zi Yan <ziy(a)nvidia.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/khugepaged.c b/mm/khugepaged.c index cdf5a581368b..7731a162a1a7 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -2293,6 +2293,17 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, continue; } + if (!folio_try_get(folio)) { + xas_reset(&xas); + continue; + } + + if (unlikely(folio != xas_reload(&xas))) { + folio_put(folio); + xas_reset(&xas); + continue; + } + if (folio_order(folio) == HPAGE_PMD_ORDER && folio->index == start) { /* Maybe PMD-mapped */ @@ -2303,23 +2314,27 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, * it's safe to skip LRU and refcount checks before * returning. */ + folio_put(folio); break; } node = folio_nid(folio); if (hpage_collapse_scan_abort(node, cc)) { result = SCAN_SCAN_ABORT; + folio_put(folio); break; } cc->node_load[node]++; if (!folio_test_lru(folio)) { result = SCAN_PAGE_LRU; + folio_put(folio); break; } - if (!is_refcount_suitable(folio)) { + if (folio_expected_ref_count(folio) + 1 != folio_ref_count(folio)) { result = SCAN_PAGE_COUNT; + folio_put(folio); break; } @@ -2331,6 +2346,7 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, */ present += folio_nr_pages(folio); + folio_put(folio); if (need_resched()) { xas_pause(&xas);

2 weeks, 3 days

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FAILED: patch "[PATCH] mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 1013af4f585fccc4d3e5c5824d174de2257f7d6d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062056-decree-conduit-b901@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1013af4f585fccc4d3e5c5824d174de2257f7d6d Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 27 May 2025 23:23:54 +0200 Subject: [PATCH] mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race huge_pmd_unshare() drops a reference on a page table that may have previously been shared across processes, potentially turning it into a normal page table used in another process in which unrelated VMAs can afterwards be installed. If this happens in the middle of a concurrent gup_fast(), gup_fast() could end up walking the page tables of another process. While I don't see any way in which that immediately leads to kernel memory corruption, it is really weird and unexpected. Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(), just like we do in khugepaged when removing page tables for a THP collapse. Link: https://lkml.kernel.org/r/20250528-hugetlb-fixes-splitrace-v2-2-1329349bad1… Link: https://lkml.kernel.org/r/20250527-hugetlb-fixes-splitrace-v1-2-f4136f5ec58… Fixes: 39dde65c9940 ("[PATCH] shared page table for hugetlb page") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7ba020d489d4..8746ed2fec13 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -7629,6 +7629,13 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, return 0; pud_clear(pud); + /* + * Once our caller drops the rmap lock, some other process might be + * using this page table as a normal, non-hugetlb page table. + * Wait for pending gup_fast() in other threads to finish before letting + * that happen. + */ + tlb_remove_table_sync_one(); ptdesc_pmd_pts_dec(virt_to_ptdesc(ptep)); mm_dec_nr_pmds(mm); return 1;

2 weeks, 3 days

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FAILED: patch "[PATCH] mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 1013af4f585fccc4d3e5c5824d174de2257f7d6d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062055-pettiness-snowshoe-2310@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1013af4f585fccc4d3e5c5824d174de2257f7d6d Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 27 May 2025 23:23:54 +0200 Subject: [PATCH] mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race huge_pmd_unshare() drops a reference on a page table that may have previously been shared across processes, potentially turning it into a normal page table used in another process in which unrelated VMAs can afterwards be installed. If this happens in the middle of a concurrent gup_fast(), gup_fast() could end up walking the page tables of another process. While I don't see any way in which that immediately leads to kernel memory corruption, it is really weird and unexpected. Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(), just like we do in khugepaged when removing page tables for a THP collapse. Link: https://lkml.kernel.org/r/20250528-hugetlb-fixes-splitrace-v2-2-1329349bad1… Link: https://lkml.kernel.org/r/20250527-hugetlb-fixes-splitrace-v1-2-f4136f5ec58… Fixes: 39dde65c9940 ("[PATCH] shared page table for hugetlb page") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7ba020d489d4..8746ed2fec13 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -7629,6 +7629,13 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, return 0; pud_clear(pud); + /* + * Once our caller drops the rmap lock, some other process might be + * using this page table as a normal, non-hugetlb page table. + * Wait for pending gup_fast() in other threads to finish before letting + * that happen. + */ + tlb_remove_table_sync_one(); ptdesc_pmd_pts_dec(virt_to_ptdesc(ptep)); mm_dec_nr_pmds(mm); return 1;

2 weeks, 3 days

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FAILED: patch "[PATCH] mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 1013af4f585fccc4d3e5c5824d174de2257f7d6d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062055-curator-nest-bade@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 1013af4f585fccc4d3e5c5824d174de2257f7d6d Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 27 May 2025 23:23:54 +0200 Subject: [PATCH] mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race huge_pmd_unshare() drops a reference on a page table that may have previously been shared across processes, potentially turning it into a normal page table used in another process in which unrelated VMAs can afterwards be installed. If this happens in the middle of a concurrent gup_fast(), gup_fast() could end up walking the page tables of another process. While I don't see any way in which that immediately leads to kernel memory corruption, it is really weird and unexpected. Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(), just like we do in khugepaged when removing page tables for a THP collapse. Link: https://lkml.kernel.org/r/20250528-hugetlb-fixes-splitrace-v2-2-1329349bad1… Link: https://lkml.kernel.org/r/20250527-hugetlb-fixes-splitrace-v1-2-f4136f5ec58… Fixes: 39dde65c9940 ("[PATCH] shared page table for hugetlb page") Signed-off-by: Jann Horn <jannh(a)google.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7ba020d489d4..8746ed2fec13 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -7629,6 +7629,13 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, return 0; pud_clear(pud); + /* + * Once our caller drops the rmap lock, some other process might be + * using this page table as a normal, non-hugetlb page table. + * Wait for pending gup_fast() in other threads to finish before letting + * that happen. + */ + tlb_remove_table_sync_one(); ptdesc_pmd_pts_dec(virt_to_ptdesc(ptep)); mm_dec_nr_pmds(mm); return 1;

2 weeks, 3 days

1
0
0 0

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