December 2024 - Linux-stable-mirror

[PATCH] btrfs: do proper folio cleanup when cow_file_range() failed

by Qu Wenruo

Just like cow_file_range(), from day 1 btrfs doesn't really clean the dirty flags, if it has an ordered extent created successfully. Per error handling protocol (according to the iomap, and the btrfs handling if it failed at the beginning of the range), we should clear all dirty flags for the involved folios. Or the range of that folio will still be marked dirty, but has no EXTENT_DEALLLOC set inside the io tree. Since the folio range is still dirty, it will still be the target for the next writeback, but since there is no EXTENT_DEALLLOC, no new ordered extent will be created for it. This means the writeback of that folio range will fall back to COW fixup, which is being marked deprecated and will trigger a crash. Unlike the fix in cow_file_range(), which holds the folio and extent lock until error or a fully successfully run, here we have no such luxury as we can fallback to COW, and in that case the extent/folio range will be unlocked by cow_file_range(). So here we introduce a new helper, cleanup_dirty_folios(), to clear the dirty flags for the involved folios. Cc: stable(a)vger.kernel.org Signed-off-by: Qu Wenruo <wqu(a)suse.com> --- fs/btrfs/inode.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e8232ac7917f..19e1b78508bd 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1969,6 +1969,46 @@ static int can_nocow_file_extent(struct btrfs_path *path, return ret < 0 ? ret : can_nocow; } +static void cleanup_dirty_folios(struct btrfs_inode *inode, + struct folio *locked_folio, + u64 start, u64 end, int error) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct address_space *mapping = inode->vfs_inode.i_mapping; + pgoff_t start_index = start >> PAGE_SHIFT; + pgoff_t end_index = end >> PAGE_SHIFT; + u32 len; + + ASSERT(end + 1 - start < U32_MAX); + len = end + 1 - start; + + /* + * Handle the locked folio first. + * btrfs_folio_clamp_*() helpers can handle range out of the folio case. + */ + btrfs_folio_clamp_clear_dirty(fs_info, locked_folio, start, len); + btrfs_folio_clamp_set_writeback(fs_info, locked_folio, start, len); + btrfs_folio_clamp_clear_writeback(fs_info, locked_folio, start, len); + + for (pgoff_t index = start_index; index <= end_index; index++) { + struct folio *folio; + + /* Already handled at the beginning. */ + if (index == locked_folio->index) + continue; + folio = __filemap_get_folio(mapping, index, FGP_LOCK, GFP_NOFS); + /* Cache already dropped, no need to do any cleanup. */ + if (IS_ERR(folio)) + continue; + btrfs_folio_clamp_clear_dirty(fs_info, folio, start, len); + btrfs_folio_clamp_set_writeback(fs_info, folio, start, len); + btrfs_folio_clamp_clear_writeback(fs_info, folio, start, len); + folio_unlock(folio); + folio_put(folio); + } + mapping_set_error(mapping, error); +} + /* * when nowcow writeback call back. This checks for snapshots or COW copies * of the extents that exist in the file, and COWs the file as required. @@ -2228,6 +2268,22 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode, return 0; error: + /* + * We have some range with ordered extent created. + * + * Ordered extents and extent maps will be cleaned up by + * btrfs_mark_ordered_io_finished() later, but we also need to cleanup + * the dirty flags of folios. + * + * Or they can be written back again, but without any EXTENT_DELALLOC flag + * in io tree. + * This will force the writeback to go COW fixup, which is being deprecated. + * + * Also such left-over dirty flags do no follow the error handling protocol. + */ + if (cur_offset > start) + cleanup_dirty_folios(inode, locked_folio, start, cur_offset - 1, ret); + /* * If an error happened while a COW region is outstanding, cur_offset * needs to be reset to cow_start to ensure the COW region is unlocked -- 2.47.1

9 months, 2 weeks

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[PATCH] btrfs: do proper folio cleanup when run_delalloc_nocow() failed

by Qu Wenruo

Just like cow_file_range(), from day 1 btrfs doesn't really clean the dirty flags, if it has an ordered extent created successfully. Per error handling protocol (according to the iomap, and the btrfs handling if it failed at the beginning of the range), we should clear all dirty flags for the involved folios. Or the range of that folio will still be marked dirty, but has no EXTENT_DEALLLOC set inside the io tree. Since the folio range is still dirty, it will still be the target for the next writeback, but since there is no EXTENT_DEALLLOC, no new ordered extent will be created for it. This means the writeback of that folio range will fall back to COW fixup, which is being marked deprecated and will trigger a crash. Unlike the fix in cow_file_range(), which holds the folio and extent lock until error or a fully successfully run, here we have no such luxury as we can fallback to COW, and in that case the extent/folio range will be unlocked by cow_file_range(). So here we introduce a new helper, cleanup_dirty_folios(), to clear the dirty flags for the involved folios. Cc: stable(a)vger.kernel.org Signed-off-by: Qu Wenruo <wqu(a)suse.com> --- fs/btrfs/inode.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e8232ac7917f..19e1b78508bd 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1969,6 +1969,46 @@ static int can_nocow_file_extent(struct btrfs_path *path, return ret < 0 ? ret : can_nocow; } +static void cleanup_dirty_folios(struct btrfs_inode *inode, + struct folio *locked_folio, + u64 start, u64 end, int error) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct address_space *mapping = inode->vfs_inode.i_mapping; + pgoff_t start_index = start >> PAGE_SHIFT; + pgoff_t end_index = end >> PAGE_SHIFT; + u32 len; + + ASSERT(end + 1 - start < U32_MAX); + len = end + 1 - start; + + /* + * Handle the locked folio first. + * btrfs_folio_clamp_*() helpers can handle range out of the folio case. + */ + btrfs_folio_clamp_clear_dirty(fs_info, locked_folio, start, len); + btrfs_folio_clamp_set_writeback(fs_info, locked_folio, start, len); + btrfs_folio_clamp_clear_writeback(fs_info, locked_folio, start, len); + + for (pgoff_t index = start_index; index <= end_index; index++) { + struct folio *folio; + + /* Already handled at the beginning. */ + if (index == locked_folio->index) + continue; + folio = __filemap_get_folio(mapping, index, FGP_LOCK, GFP_NOFS); + /* Cache already dropped, no need to do any cleanup. */ + if (IS_ERR(folio)) + continue; + btrfs_folio_clamp_clear_dirty(fs_info, folio, start, len); + btrfs_folio_clamp_set_writeback(fs_info, folio, start, len); + btrfs_folio_clamp_clear_writeback(fs_info, folio, start, len); + folio_unlock(folio); + folio_put(folio); + } + mapping_set_error(mapping, error); +} + /* * when nowcow writeback call back. This checks for snapshots or COW copies * of the extents that exist in the file, and COWs the file as required. @@ -2228,6 +2268,22 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode, return 0; error: + /* + * We have some range with ordered extent created. + * + * Ordered extents and extent maps will be cleaned up by + * btrfs_mark_ordered_io_finished() later, but we also need to cleanup + * the dirty flags of folios. + * + * Or they can be written back again, but without any EXTENT_DELALLOC flag + * in io tree. + * This will force the writeback to go COW fixup, which is being deprecated. + * + * Also such left-over dirty flags do no follow the error handling protocol. + */ + if (cur_offset > start) + cleanup_dirty_folios(inode, locked_folio, start, cur_offset - 1, ret); + /* * If an error happened while a COW region is outstanding, cur_offset * needs to be reset to cow_start to ensure the COW region is unlocked -- 2.47.1

9 months, 2 weeks

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[PATCH] drm: amd: Fix potential NULL pointer dereference in atomctrl_get_smc_sclk_range_table

by Ivan Stepchenko

The function atomctrl_get_smc_sclk_range_table() does not check the return value of smu_atom_get_data_table(). If smu_atom_get_data_table() fails to retrieve SMU_Info table, it returns NULL which is later dereferenced. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: a23eefa2f461 ("drm/amd/powerplay: enable dpm for baffin.") Cc: stable(a)vger.kernel.org Signed-off-by: Ivan Stepchenko <sid(a)itb.spb.ru> --- drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c index fe24219c3bf4..4bd92fd782be 100644 --- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c +++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppatomctrl.c @@ -992,6 +992,8 @@ int atomctrl_get_smc_sclk_range_table(struct pp_hwmgr *hwmgr, struct pp_atom_ctr GetIndexIntoMasterTable(DATA, SMU_Info), &size, &frev, &crev); + if (!psmu_info) + return -EINVAL; for (i = 0; i < psmu_info->ucSclkEntryNum; i++) { table->entry[i].ucVco_setting = psmu_info->asSclkFcwRangeEntry[i].ucVco_setting; -- 2.34.1

9 months, 2 weeks

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Performance Degradation After Upgrading to Kernel 6.8

by Chenbo Lu

Hello, I am experiencing a significant performance degradation after upgrading my kernel from version 6.6 to 6.8 and would appreciate any insights or suggestions. I am running a high-load simulation system that spawns more than 1000 threads and the overall CPU usage is 30%+ . Most of the threads are using real-time scheduling (SCHED_RR), and the threads of a model are using SCHED_DEADLINE. After upgrading the kernel, I noticed that the execution time of my model has increased from 4.5ms to 6ms. What I Have Done So Far: 1. I found this [bug report](https://bugzilla.kernel.org/show_bug.cgi?id=219366#c7) and reverted the commit efa7df3e3bb5da8e6abbe37727417f32a37fba47 mentioned in the post. Unfortunately, this did not resolve the issue. 2. I performed a git bisect and found that after these two commits related to scheduling (RT and deadline) were merged, the problem happened. They are 612f769edd06a6e42f7cd72425488e68ddaeef0a, 5fe7765997b139e2d922b58359dea181efe618f9 After reverting these two commits, the model execution time improved to around 5 ms. 3. I revert two more commits, and the execution time is back to 4.7ms: 63ba8422f876e32ee564ea95da9a7313b13ff0a1, efa7df3e3bb5da8e6abbe37727417f32a37fba47 My questions are: 1.Has anyone else experienced similar performance degradation after upgrading to kernel 6.8? 2.Can anyone explain why these two commits are causing the problem? I am not very familiar with the kernel code and would appreciate any insights. 3.Are there any additional settings or configurations I need to apply when using kernel 6.8 to avoid this issue? My CPU is AMD Ryzen Threadripper 3970X, and my desktop uses Ubuntu 24.04. Thanks again for any insights or suggestions. Please let me know if any other information is needed. Best, Chenbo -- This email and any relevant attachments may include confidential and/or proprietary information. Any distribution or use by anyone other than the intended recipient(s) or other than for the intended purpose(s) is prohibited and may be unlawful. If you are not the intended recipient of this message, please notify the sender by replying to this message and then delete it from your system.

9 months, 2 weeks

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[PATCH v5.10-v6.1] driver core: bus: Fix double free in driver API bus_register()

by Brennan Lamoreaux

From: Zijun Hu <quic_zijuhu(a)quicinc.com> [ Upstream commit bfa54a793ba77ef696755b66f3ac4ed00c7d1248 ] For bus_register(), any error which happens after kset_register() will cause that @priv are freed twice, fixed by setting @priv with NULL after the first free. Signed-off-by: Zijun Hu <quic_zijuhu(a)quicinc.com> Link: https://lore.kernel.org/r/20240727-bus_register_fix-v1-1-fed8dd0dba7a@quici… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> [ Brennan : Backport requires bus->p = NULL instead of priv = NULL ] Signed-off-by: Brennan Lamoreaux <brennan.lamoreaux(a)broadcom.com> --- drivers/base/bus.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 339a9edcde5f..941532ddfdc6 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -853,6 +853,8 @@ int bus_register(struct bus_type *bus) bus_remove_file(bus, &bus_attr_uevent); bus_uevent_fail: kset_unregister(&bus->p->subsys); + /* Above kset_unregister() will kfree @bus->p */ + bus->p = NULL; out: kfree(bus->p); bus->p = NULL; -- 2.39.4

9 months, 2 weeks

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FAILED: patch "[PATCH] Compiler Attributes: disable __counted_by for clang < 19.1.3" 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 f06e108a3dc53c0f5234d18de0bd224753db5019 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024120221-gizzard-thermos-ba19@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f06e108a3dc53c0f5234d18de0bd224753db5019 Mon Sep 17 00:00:00 2001 From: Jan Hendrik Farr <kernel(a)jfarr.cc> Date: Tue, 29 Oct 2024 15:00:36 +0100 Subject: [PATCH] Compiler Attributes: disable __counted_by for clang < 19.1.3 This patch disables __counted_by for clang versions < 19.1.3 because of the two issues listed below. It does this by introducing CONFIG_CC_HAS_COUNTED_BY. 1. clang < 19.1.2 has a bug that can lead to __bdos returning 0: https://github.com/llvm/llvm-project/pull/110497 2. clang < 19.1.3 has a bug that can lead to __bdos being off by 4: https://github.com/llvm/llvm-project/pull/112636 Fixes: c8248faf3ca2 ("Compiler Attributes: counted_by: Adjust name and identifier expansion") Cc: stable(a)vger.kernel.org # 6.6.x: 16c31dd7fdf6: Compiler Attributes: counted_by: bump min gcc version Cc: stable(a)vger.kernel.org # 6.6.x: 2993eb7a8d34: Compiler Attributes: counted_by: fixup clang URL Cc: stable(a)vger.kernel.org # 6.6.x: 231dc3f0c936: lkdtm/bugs: Improve warning message for compilers without counted_by support Cc: stable(a)vger.kernel.org # 6.6.x Reported-by: Nathan Chancellor <nathan(a)kernel.org> Closes: https://lore.kernel.org/all/20240913164630.GA4091534@thelio-3990X/ Reported-by: kernel test robot <oliver.sang(a)intel.com> Closes: https://lore.kernel.org/oe-lkp/202409260949.a1254989-oliver.sang@intel.com Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586… Suggested-by: Nathan Chancellor <nathan(a)kernel.org> Signed-off-by: Jan Hendrik Farr <kernel(a)jfarr.cc> Reviewed-by: Nathan Chancellor <nathan(a)kernel.org> Tested-by: Nathan Chancellor <nathan(a)kernel.org> Reviewed-by: Miguel Ojeda <ojeda(a)kernel.org> Reviewed-by: Thorsten Blum <thorsten.blum(a)linux.dev> Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc Signed-off-by: Kees Cook <kees(a)kernel.org> diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index 62ba01525479..376047beea3d 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -445,7 +445,7 @@ static void lkdtm_FAM_BOUNDS(void) pr_err("FAIL: survived access of invalid flexible array member index!\n"); - if (!__has_attribute(__counted_by__)) + if (!IS_ENABLED(CONFIG_CC_HAS_COUNTED_BY)) pr_warn("This is expected since this %s was built with a compiler that does not support __counted_by\n", lkdtm_kernel_info); else if (IS_ENABLED(CONFIG_UBSAN_BOUNDS)) diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index 32284cd26d52..c16d4199bf92 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -94,19 +94,6 @@ # define __copy(symbol) #endif -/* - * Optional: only supported since gcc >= 15 - * Optional: only supported since clang >= 18 - * - * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 - * clang: https://github.com/llvm/llvm-project/pull/76348 - */ -#if __has_attribute(__counted_by__) -# define __counted_by(member) __attribute__((__counted_by__(member))) -#else -# define __counted_by(member) -#endif - /* * Optional: not supported by gcc * Optional: only supported since clang >= 14.0 diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 1a957ea2f4fe..639be0f30b45 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -323,6 +323,25 @@ struct ftrace_likely_data { #define __no_sanitize_or_inline __always_inline #endif +/* + * Optional: only supported since gcc >= 15 + * Optional: only supported since clang >= 18 + * + * gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896 + * clang: https://github.com/llvm/llvm-project/pull/76348 + * + * __bdos on clang < 19.1.2 can erroneously return 0: + * https://github.com/llvm/llvm-project/pull/110497 + * + * __bdos on clang < 19.1.3 can be off by 4: + * https://github.com/llvm/llvm-project/pull/112636 + */ +#ifdef CONFIG_CC_HAS_COUNTED_BY +# define __counted_by(member) __attribute__((__counted_by__(member))) +#else +# define __counted_by(member) +#endif + /* * Apply __counted_by() when the Endianness matches to increase test coverage. */ diff --git a/init/Kconfig b/init/Kconfig index 530a382ee0fe..92f106cf5572 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -116,6 +116,15 @@ config CC_HAS_ASM_INLINE config CC_HAS_NO_PROFILE_FN_ATTR def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror) +config CC_HAS_COUNTED_BY + # TODO: when gcc 15 is released remove the build test and add + # a gcc version check + def_bool $(success,echo 'struct flex { int count; int array[] __attribute__((__counted_by__(count))); };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror) + # clang needs to be at least 19.1.3 to avoid __bdos miscalculations + # https://github.com/llvm/llvm-project/pull/110497 + # https://github.com/llvm/llvm-project/pull/112636 + depends on !(CC_IS_CLANG && CLANG_VERSION < 190103) + config PAHOLE_VERSION int default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE)) diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c index 2abc78367dd1..5222c6393f11 100644 --- a/lib/overflow_kunit.c +++ b/lib/overflow_kunit.c @@ -1187,7 +1187,7 @@ static void DEFINE_FLEX_test(struct kunit *test) { /* Using _RAW_ on a __counted_by struct will initialize "counter" to zero */ DEFINE_RAW_FLEX(struct foo, two_but_zero, array, 2); -#if __has_attribute(__counted_by__) +#ifdef CONFIG_CC_HAS_COUNTED_BY int expected_raw_size = sizeof(struct foo); #else int expected_raw_size = sizeof(struct foo) + 2 * sizeof(s16);

9 months, 2 weeks

3
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[PATCH] usb: misc: onboard_usb_dev: skip suspend/resume sequence for USB5744 SMBus support

by Radhey Shyam Pandey

USB5744 SMBus initialization is done once in probe() and doing it in resume is not supported so avoid going into suspend and reset the HUB. There is a sysfs property 'always_powered_in_suspend' to implement this feature but since default state should be set to a working configuration so override this property value. It fixes the suspend/resume testcase on Kria KR260 Robotics Starter Kit. Fixes: 6782311d04df ("usb: misc: onboard_usb_dev: add Microchip usb5744 SMBus programming support") Cc: stable(a)vger.kernel.org Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey(a)amd.com> --- drivers/usb/misc/onboard_usb_dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/misc/onboard_usb_dev.c b/drivers/usb/misc/onboard_usb_dev.c index 36b11127280f..75ac3c6aa92d 100644 --- a/drivers/usb/misc/onboard_usb_dev.c +++ b/drivers/usb/misc/onboard_usb_dev.c @@ -407,8 +407,10 @@ static int onboard_dev_probe(struct platform_device *pdev) } if (of_device_is_compatible(pdev->dev.of_node, "usb424,2744") || - of_device_is_compatible(pdev->dev.of_node, "usb424,5744")) + of_device_is_compatible(pdev->dev.of_node, "usb424,5744")) { err = onboard_dev_5744_i2c_init(client); + onboard_dev->always_powered_in_suspend = true; + } put_device(&client->dev); if (err < 0) -- 2.34.1

9 months, 2 weeks

1
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[PATCH v2] pps: Remove embedded cdev to fix a use-after-free

by Calvin Owens

On a board running ntpd and gpsd, I'm seeing a consistent use-after-free in sys_exit() from gpsd when rebooting: pps pps1: removed ------------[ cut here ]------------ kobject: '(null)' (00000000db4bec24): is not initialized, yet kobject_put() is being called. WARNING: CPU: 2 PID: 440 at lib/kobject.c:734 kobject_put+0x120/0x150 CPU: 2 UID: 299 PID: 440 Comm: gpsd Not tainted 6.11.0-rc6-00308-gb31c44928842 #1 Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : kobject_put+0x120/0x150 lr : kobject_put+0x120/0x150 sp : ffffffc0803d3ae0 x29: ffffffc0803d3ae0 x28: ffffff8042dc9738 x27: 0000000000000001 x26: 0000000000000000 x25: ffffff8042dc9040 x24: ffffff8042dc9440 x23: ffffff80402a4620 x22: ffffff8042ef4bd0 x21: ffffff80405cb600 x20: 000000000008001b x19: ffffff8040b3b6e0 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 696e6920746f6e20 x14: 7369203a29343263 x13: 205d303434542020 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: kobject_put+0x120/0x150 cdev_put+0x20/0x3c __fput+0x2c4/0x2d8 ____fput+0x1c/0x38 task_work_run+0x70/0xfc do_exit+0x2a0/0x924 do_group_exit+0x34/0x90 get_signal+0x7fc/0x8c0 do_signal+0x128/0x13b4 do_notify_resume+0xdc/0x160 el0_svc+0xd4/0xf8 el0t_64_sync_handler+0x140/0x14c el0t_64_sync+0x190/0x194 ---[ end trace 0000000000000000 ]--- ...followed by more symptoms of corruption, with similar stacks: refcount_t: underflow; use-after-free. kernel BUG at lib/list_debug.c:62! Kernel panic - not syncing: Oops - BUG: Fatal exception This happens because pps_device_destruct() frees the pps_device with the embedded cdev immediately after calling cdev_del(), but, as the comment above cdev_del() notes, fops for previously opened cdevs are still callable even after cdev_del() returns. I think this bug has always been there: I can't explain why it suddenly started happening every time I reboot this particular board. In commit d953e0e837e6 ("pps: Fix a use-after free bug when unregistering a source."), George Spelvin suggested removing the embedded cdev. That seems like the simplest way to fix this, so I've implemented his suggestion, with pps_idr becoming the source of truth for which minor corresponds to which device. But now that pps_idr defines userspace visibility instead of cdev_add(), we need to be sure the pps->dev kobject refcount can't reach zero while userspace can still find it again. So, the idr_remove() call moves to pps_unregister_cdev(), and pps_idr now holds a reference to the pps->dev kobject. pps_core: source serial1 got cdev (251:1) <...> pps pps1: removed pps_core: unregistering pps1 pps_core: deallocating pps1 Fixes: d953e0e837e6 ("pps: Fix a use-after free bug when unregistering a source.") Cc: stable(a)vger.kernel.org Signed-off-by: Calvin Owens <calvin(a)wbinvd.org> --- Changes in v2: - Don't move pr_debug() from pps_device_destruct() to pps_unregister_cdev() - Actually add stable(a)vger.kernel.org to CC --- drivers/pps/pps.c | 83 ++++++++++++++++++++------------------ include/linux/pps_kernel.h | 1 - 2 files changed, 44 insertions(+), 40 deletions(-) diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index 5d19baae6a38..6980ab17f314 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -25,7 +25,7 @@ * Local variables */ -static dev_t pps_devt; +static int pps_major; static struct class *pps_class; static DEFINE_MUTEX(pps_idr_lock); @@ -296,19 +296,35 @@ static long pps_cdev_compat_ioctl(struct file *file, #define pps_cdev_compat_ioctl NULL #endif +static struct pps_device *pps_idr_get(unsigned long id) +{ + struct pps_device *pps; + + mutex_lock(&pps_idr_lock); + pps = idr_find(&pps_idr, id); + if (pps) + kobject_get(&pps->dev->kobj); + + mutex_unlock(&pps_idr_lock); + return pps; +} + static int pps_cdev_open(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); + struct pps_device *pps = pps_idr_get(iminor(inode)); + + if (!pps) + return -ENODEV; + file->private_data = pps; - kobject_get(&pps->dev->kobj); return 0; } static int pps_cdev_release(struct inode *inode, struct file *file) { - struct pps_device *pps = container_of(inode->i_cdev, - struct pps_device, cdev); + struct pps_device *pps = file->private_data; + + WARN_ON(pps->id != iminor(inode)); kobject_put(&pps->dev->kobj); return 0; } @@ -332,14 +348,7 @@ static void pps_device_destruct(struct device *dev) { struct pps_device *pps = dev_get_drvdata(dev); - cdev_del(&pps->cdev); - - /* Now we can release the ID for re-use */ pr_debug("deallocating pps%d\n", pps->id); - mutex_lock(&pps_idr_lock); - idr_remove(&pps_idr, pps->id); - mutex_unlock(&pps_idr_lock); - kfree(dev); kfree(pps); } @@ -364,39 +373,26 @@ int pps_register_cdev(struct pps_device *pps) goto out_unlock; } pps->id = err; - mutex_unlock(&pps_idr_lock); - devt = MKDEV(MAJOR(pps_devt), pps->id); - - cdev_init(&pps->cdev, &pps_cdev_fops); - pps->cdev.owner = pps->info.owner; - - err = cdev_add(&pps->cdev, devt, 1); - if (err) { - pr_err("%s: failed to add char device %d:%d\n", - pps->info.name, MAJOR(pps_devt), pps->id); - goto free_idr; - } + devt = MKDEV(pps_major, pps->id); pps->dev = device_create(pps_class, pps->info.dev, devt, pps, "pps%d", pps->id); if (IS_ERR(pps->dev)) { err = PTR_ERR(pps->dev); - goto del_cdev; + goto free_idr; } /* Override the release function with our own */ pps->dev->release = pps_device_destruct; - pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, - MAJOR(pps_devt), pps->id); + pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, pps_major, + pps->id); + kobject_get(&pps->dev->kobj); + mutex_unlock(&pps_idr_lock); return 0; -del_cdev: - cdev_del(&pps->cdev); - free_idr: - mutex_lock(&pps_idr_lock); idr_remove(&pps_idr, pps->id); out_unlock: mutex_unlock(&pps_idr_lock); @@ -408,6 +404,12 @@ void pps_unregister_cdev(struct pps_device *pps) pr_debug("unregistering pps%d\n", pps->id); pps->lookup_cookie = NULL; device_destroy(pps_class, pps->dev->devt); + + /* Now we can release the ID for re-use */ + mutex_lock(&pps_idr_lock); + idr_remove(&pps_idr, pps->id); + kobject_put(&pps->dev->kobj); + mutex_unlock(&pps_idr_lock); } /* @@ -427,6 +429,11 @@ void pps_unregister_cdev(struct pps_device *pps) * so that it will not be used again, even if the pps device cannot * be removed from the idr due to pending references holding the minor * number in use. + * + * Since pps_idr holds a reference to the kobject, the returned + * pps_device is guaranteed to be valid until pps_unregister_cdev() is + * called on it. But after calling pps_unregister_cdev(), it may be + * freed at any time. */ struct pps_device *pps_lookup_dev(void const *cookie) { @@ -449,13 +456,11 @@ EXPORT_SYMBOL(pps_lookup_dev); static void __exit pps_exit(void) { class_destroy(pps_class); - unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); + __unregister_chrdev(pps_major, 0, PPS_MAX_SOURCES, "pps"); } static int __init pps_init(void) { - int err; - pps_class = class_create("pps"); if (IS_ERR(pps_class)) { pr_err("failed to allocate class\n"); @@ -463,8 +468,9 @@ static int __init pps_init(void) } pps_class->dev_groups = pps_groups; - err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); - if (err < 0) { + pps_major = __register_chrdev(0, 0, PPS_MAX_SOURCES, "pps", + &pps_cdev_fops); + if (pps_major < 0) { pr_err("failed to allocate char device region\n"); goto remove_class; } @@ -477,8 +483,7 @@ static int __init pps_init(void) remove_class: class_destroy(pps_class); - - return err; + return pps_major; } subsys_initcall(pps_init); diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h index 78c8ac4951b5..8ee312788118 100644 --- a/include/linux/pps_kernel.h +++ b/include/linux/pps_kernel.h @@ -56,7 +56,6 @@ struct pps_device { unsigned int id; /* PPS source unique ID */ void const *lookup_cookie; /* For pps_lookup_dev() only */ - struct cdev cdev; struct device *dev; struct fasync_struct *async_queue; /* fasync method */ spinlock_t lock; -- 2.45.2

9 months, 2 weeks

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[PATCH v3] usb: dwc3: xilinx: make sure pipe clock is deselected in usb2 only mode

by Radhey Shyam Pandey

From: Neal Frager <neal.frager(a)amd.com> When the USB3 PHY is not defined in the Linux device tree, there could still be a case where there is a USB3 PHY active on the board and enabled by the first stage bootloader. If serdes clock is being used then the USB will fail to enumerate devices in 2.0 only mode. To solve this, make sure that the PIPE clock is deselected whenever the USB3 PHY is not defined and guarantees that the USB2 only mode will work in all cases. Fixes: 9678f3361afc ("usb: dwc3: xilinx: Skip resets and USB3 register settings for USB2.0 mode") Cc: stable(a)vger.kernel.org Signed-off-by: Neal Frager <neal.frager(a)amd.com> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey(a)amd.com> Acked-by: Peter Korsgaard <peter(a)korsgaard.com> --- Changes for v3: - Modify commit description to drop second "is" and add Peter ack. Changes for v2: - Add stable(a)vger.kernel.org in CC. --- drivers/usb/dwc3/dwc3-xilinx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c index e3738e1610db..a33a42ba0249 100644 --- a/drivers/usb/dwc3/dwc3-xilinx.c +++ b/drivers/usb/dwc3/dwc3-xilinx.c @@ -121,8 +121,11 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data) * in use but the usb3-phy entry is missing from the device tree. * Therefore, skip these operations in this case. */ - if (!priv_data->usb3_phy) + if (!priv_data->usb3_phy) { + /* Deselect the PIPE Clock Select bit in FPD PIPE Clock register */ + writel(PIPE_CLK_DESELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK); goto skip_usb3_phy; + } crst = devm_reset_control_get_exclusive(dev, "usb_crst"); if (IS_ERR(crst)) { -- 2.34.1

9 months, 2 weeks

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[PATCH 4.19.y 1/1] inet: inet_defrag: prevent sk release while still in use

by Saeed Mirzamohammadi

From: Florian Westphal <fw(a)strlen.de> commit 18685451fc4e546fc0e718580d32df3c0e5c8272 upstream. ip_local_out() and other functions can pass skb->sk as function argument. If the skb is a fragment and reassembly happens before such function call returns, the sk must not be released. This affects skb fragments reassembled via netfilter or similar modules, e.g. openvswitch or ct_act.c, when run as part of tx pipeline. Eric Dumazet made an initial analysis of this bug. Quoting Eric: Calling ip_defrag() in output path is also implying skb_orphan(), which is buggy because output path relies on sk not disappearing. A relevant old patch about the issue was : 8282f27449bf ("inet: frag: Always orphan skbs inside ip_defrag()") [..] net/ipv4/ip_output.c depends on skb->sk being set, and probably to an inet socket, not an arbitrary one. If we orphan the packet in ipvlan, then downstream things like FQ packet scheduler will not work properly. We need to change ip_defrag() to only use skb_orphan() when really needed, ie whenever frag_list is going to be used. Eric suggested to stash sk in fragment queue and made an initial patch. However there is a problem with this: If skb is refragmented again right after, ip_do_fragment() will copy head->sk to the new fragments, and sets up destructor to sock_wfree. IOW, we have no choice but to fix up sk_wmem accouting to reflect the fully reassembled skb, else wmem will underflow. This change moves the orphan down into the core, to last possible moment. As ip_defrag_offset is aliased with sk_buff->sk member, we must move the offset into the FRAG_CB, else skb->sk gets clobbered. This allows to delay the orphaning long enough to learn if the skb has to be queued or if the skb is completing the reasm queue. In the former case, things work as before, skb is orphaned. This is safe because skb gets queued/stolen and won't continue past reasm engine. In the latter case, we will steal the skb->sk reference, reattach it to the head skb, and fix up wmem accouting when inet_frag inflates truesize. Fixes: 7026b1ddb6b8 ("netfilter: Pass socket pointer down through okfn().") Diagnosed-by: Eric Dumazet <edumazet(a)google.com> Reported-by: xingwei lee <xrivendell7(a)gmail.com> Reported-by: yue sun <samsun1006219(a)gmail.com> Reported-by: syzbot+e5167d7144a62715044c(a)syzkaller.appspotmail.com Signed-off-by: Florian Westphal <fw(a)strlen.de> Reviewed-by: Eric Dumazet <edumazet(a)google.com> Link: https://lore.kernel.org/r/20240326101845.30836-1-fw@strlen.de Signed-off-by: Paolo Abeni <pabeni(a)redhat.com> Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi(a)oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> (cherry picked from commit 1b6de5e6575b56502665c65cf93b0ae6aa0f51ab) Cc: <stable(a)vger.kernel.org> # 4.19+ Signed-off-by: Saeed Mirzamohammadi <saeed.mirzamohammadi(a)oracle.com> --- include/linux/skbuff.h | 5 +- net/core/sock_destructor.h | 12 +++++ net/ipv4/inet_fragment.c | 70 ++++++++++++++++++++----- net/ipv4/ip_fragment.c | 2 +- net/ipv6/netfilter/nf_conntrack_reasm.c | 2 +- 5 files changed, 72 insertions(+), 19 deletions(-) create mode 100644 net/core/sock_destructor.h diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index f97734f34746..f5f76a04fdac 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -682,10 +682,7 @@ struct sk_buff { struct list_head list; }; - union { - struct sock *sk; - int ip_defrag_offset; - }; + struct sock *sk; union { ktime_t tstamp; diff --git a/net/core/sock_destructor.h b/net/core/sock_destructor.h new file mode 100644 index 000000000000..2f396e6bfba5 --- /dev/null +++ b/net/core/sock_destructor.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _NET_CORE_SOCK_DESTRUCTOR_H +#define _NET_CORE_SOCK_DESTRUCTOR_H +#include <net/tcp.h> + +static inline bool is_skb_wmem(const struct sk_buff *skb) +{ + return skb->destructor == sock_wfree || + skb->destructor == __sock_wfree || + (IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree); +} +#endif diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index 9f69411251d0..9144c3cf984c 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -28,6 +28,8 @@ #include <net/ip.h> #include <net/ipv6.h> +#include "../core/sock_destructor.h" + /* Use skb->cb to track consecutive/adjacent fragments coming at * the end of the queue. Nodes in the rb-tree queue will * contain "runs" of one or more adjacent fragments. @@ -43,6 +45,7 @@ struct ipfrag_skb_cb { }; struct sk_buff *next_frag; int frag_run_len; + int ip_defrag_offset; }; #define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb)) @@ -319,12 +322,12 @@ int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, */ if (!last) fragrun_create(q, skb); /* First fragment. */ - else if (last->ip_defrag_offset + last->len < end) { + else if (FRAG_CB(last)->ip_defrag_offset + last->len < end) { /* This is the common case: skb goes to the end. */ /* Detect and discard overlaps. */ - if (offset < last->ip_defrag_offset + last->len) + if (offset < FRAG_CB(last)->ip_defrag_offset + last->len) return IPFRAG_OVERLAP; - if (offset == last->ip_defrag_offset + last->len) + if (offset == FRAG_CB(last)->ip_defrag_offset + last->len) fragrun_append_to_last(q, skb); else fragrun_create(q, skb); @@ -341,13 +344,13 @@ int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, parent = *rbn; curr = rb_to_skb(parent); - curr_run_end = curr->ip_defrag_offset + + curr_run_end = FRAG_CB(curr)->ip_defrag_offset + FRAG_CB(curr)->frag_run_len; - if (end <= curr->ip_defrag_offset) + if (end <= FRAG_CB(curr)->ip_defrag_offset) rbn = &parent->rb_left; else if (offset >= curr_run_end) rbn = &parent->rb_right; - else if (offset >= curr->ip_defrag_offset && + else if (offset >= FRAG_CB(curr)->ip_defrag_offset && end <= curr_run_end) return IPFRAG_DUP; else @@ -361,7 +364,7 @@ int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, rb_insert_color(&skb->rbnode, &q->rb_fragments); } - skb->ip_defrag_offset = offset; + FRAG_CB(skb)->ip_defrag_offset = offset; return IPFRAG_OK; } @@ -371,13 +374,28 @@ void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, struct sk_buff *parent) { struct sk_buff *fp, *head = skb_rb_first(&q->rb_fragments); - struct sk_buff **nextp; + void (*destructor)(struct sk_buff *); + unsigned int orig_truesize = 0; + struct sk_buff **nextp = NULL; + struct sock *sk = skb->sk; int delta; + if (sk && is_skb_wmem(skb)) { + /* TX: skb->sk might have been passed as argument to + * dst->output and must remain valid until tx completes. + * + * Move sk to reassembled skb and fix up wmem accounting. + */ + orig_truesize = skb->truesize; + destructor = skb->destructor; + } + if (head != skb) { fp = skb_clone(skb, GFP_ATOMIC); - if (!fp) - return NULL; + if (!fp) { + head = skb; + goto out_restore_sk; + } FRAG_CB(fp)->next_frag = FRAG_CB(skb)->next_frag; if (RB_EMPTY_NODE(&skb->rbnode)) FRAG_CB(parent)->next_frag = fp; @@ -386,6 +404,12 @@ void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, &q->rb_fragments); if (q->fragments_tail == skb) q->fragments_tail = fp; + + if (orig_truesize) { + /* prevent skb_morph from releasing sk */ + skb->sk = NULL; + skb->destructor = NULL; + } skb_morph(skb, head); FRAG_CB(skb)->next_frag = FRAG_CB(head)->next_frag; rb_replace_node(&head->rbnode, &skb->rbnode, @@ -393,13 +417,13 @@ void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, consume_skb(head); head = skb; } - WARN_ON(head->ip_defrag_offset != 0); + WARN_ON(FRAG_CB(head)->ip_defrag_offset != 0); delta = -head->truesize; /* Head of list must not be cloned. */ if (skb_unclone(head, GFP_ATOMIC)) - return NULL; + goto out_restore_sk; delta += head->truesize; if (delta) @@ -415,7 +439,7 @@ void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, clone = alloc_skb(0, GFP_ATOMIC); if (!clone) - return NULL; + goto out_restore_sk; skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; skb_frag_list_init(head); for (i = 0; i < skb_shinfo(head)->nr_frags; i++) @@ -432,6 +456,21 @@ void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, nextp = &skb_shinfo(head)->frag_list; } +out_restore_sk: + if (orig_truesize) { + int ts_delta = head->truesize - orig_truesize; + + /* if this reassembled skb is fragmented later, + * fraglist skbs will get skb->sk assigned from head->sk, + * and each frag skb will be released via sock_wfree. + * + * Update sk_wmem_alloc. + */ + head->sk = sk; + head->destructor = destructor; + refcount_add(ts_delta, &sk->sk_wmem_alloc); + } + return nextp; } EXPORT_SYMBOL(inet_frag_reasm_prepare); @@ -439,6 +478,8 @@ EXPORT_SYMBOL(inet_frag_reasm_prepare); void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, void *reasm_data) { + struct sock *sk = is_skb_wmem(head) ? head->sk : NULL; + const unsigned int head_truesize = head->truesize; struct sk_buff **nextp = (struct sk_buff **)reasm_data; struct rb_node *rbn; struct sk_buff *fp; @@ -484,6 +525,9 @@ void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head, skb_mark_not_on_list(head); head->prev = NULL; head->tstamp = q->stamp; + + if (sk) + refcount_add(sum_truesize - head_truesize, &sk->sk_wmem_alloc); } EXPORT_SYMBOL(inet_frag_reasm_finish); diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 5a1d39e32196..84544e5df7fc 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -380,6 +380,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) } skb_dst_drop(skb); + skb_orphan(skb); return -EINPROGRESS; insert_error: @@ -477,7 +478,6 @@ int ip_defrag(struct net *net, struct sk_buff *skb, u32 user) struct ipq *qp; __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS); - skb_orphan(skb); /* Lookup (or create) queue header */ qp = ip_find(net, ip_hdr(skb), user, vif); diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 35d5a76867d0..8aab62c330ef 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -307,6 +307,7 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb, } skb_dst_drop(skb); + skb_orphan(skb); return -EINPROGRESS; insert_error: @@ -473,7 +474,6 @@ int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user) hdr = ipv6_hdr(skb); fhdr = (struct frag_hdr *)skb_transport_header(skb); - skb_orphan(skb); fq = fq_find(net, fhdr->identification, user, hdr, skb->dev ? skb->dev->ifindex : 0); if (fq == NULL) { -- 2.46.0

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Linux-stable-mirror December 2024