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[to-be-updated] kasan-unpoison-vms-addresses-with-a-common-tag.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: kasan: unpoison vms[area] addresses with a common tag has been removed from the -mm tree. Its filename was kasan-unpoison-vms-addresses-with-a-common-tag.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> Subject: kasan: unpoison vms[area] addresses with a common tag Date: Tue, 04 Nov 2025 14:49:48 +0000 A KASAN tag mismatch, possibly causing a kernel panic, can be observed on systems with a tag-based KASAN enabled and with multiple NUMA nodes. It was reported on arm64 and reproduced on x86. It can be explained in the following points: 1. There can be more than one virtual memory chunk. 2. Chunk's base address has a tag. 3. The base address points at the first chunk and thus inherits the tag of the first chunk. 4. The subsequent chunks will be accessed with the tag from the first chunk. 5. Thus, the subsequent chunks need to have their tag set to match that of the first chunk. Unpoison all vm_structs after allocating them for the percpu allocator. Use the same tag to resolve the pcpu chunk address mismatch. Link: https://lkml.kernel.org/r/cf8fe0ffcdbf54e06d9df26c8473b123c4065f02.17622670… Fixes: 1d96320f8d53 ("kasan, vmalloc: add vmalloc tagging for SW_TAGS") Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> Tested-by: Baoquan He <bhe(a)redhat.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Marco Elver <elver(a)google.com> Cc: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> [6.1+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/kasan/common.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/mm/kasan/common.c~kasan-unpoison-vms-addresses-with-a-common-tag +++ a/mm/kasan/common.c @@ -584,12 +584,20 @@ bool __kasan_check_byte(const void *addr return true; } +/* + * A tag mismatch happens when calculating per-cpu chunk addresses, because + * they all inherit the tag from vms[0]->addr, even when nr_vms is bigger + * than 1. This is a problem because all the vms[]->addr come from separate + * allocations and have different tags so while the calculated address is + * correct the tag isn't. + */ void __kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms) { int area; for (area = 0 ; area < nr_vms ; area++) { kasan_poison(vms[area]->addr, vms[area]->size, - arch_kasan_get_tag(vms[area]->addr), false); + arch_kasan_get_tag(vms[0]->addr), false); + arch_kasan_set_tag(vms[area]->addr, arch_kasan_get_tag(vms[0]->addr)); } } _ Patches currently in -mm which might be from maciej.wieczor-retman(a)intel.com are

1 month, 2 weeks

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[to-be-updated] kasan-unpoison-pcpu-chunks-with-base-address-tag.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: kasan: unpoison pcpu chunks with base address tag has been removed from the -mm tree. Its filename was kasan-unpoison-pcpu-chunks-with-base-address-tag.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> Subject: kasan: unpoison pcpu chunks with base address tag Date: Tue, 04 Nov 2025 14:49:08 +0000 Patch series "kasan: vmalloc: Fix incorrect tag assignment with multiple vm_structs". A KASAN tag mismatch, possibly resulting in a kernel panic, can be observed on systems with a tag-based KASAN enabled and with multiple NUMA nodes. Initially it was only noticed on x86 [1] but later a similar issue was also reported on arm64 [2]. Specifically the problem is related to how vm_structs interact with pcpu_chunks - both when they are allocated, assigned and when pcpu_chunk addresses are derived. When vm_structs are allocated they are tagged if vmalloc support is enabled along the KASAN mode. Later when first pcpu chunk is allocated it gets its 'base_addr' field set to the first allocated vm_struct. With that it inherits that vm_struct's tag. When pcpu_chunk addresses are later derived (by pcpu_chunk_addr(), for example in pcpu_alloc_noprof()) the base_addr field is used and offsets are added to it. If the initial conditions are satisfied then some of the offsets will point into memory allocated with a different vm_struct. So while the lower bits will get accurately derived the tag bits in the top of the pointer won't match the shadow memory contents. The solution (proposed at v2 of the x86 KASAN series [3]) is to tag the vm_structs the same when allocating them for the per cpu allocator (in pcpu_get_vm_areas()). Originally these patches were part of the x86 KASAN series [4]. This patch (of 2): A KASAN tag mismatch, possibly causing a kernel panic, can be observed on systems with a tag-based KASAN enabled and with multiple NUMA nodes. It was reported on arm64 and reproduced on x86. It can be explained in the following points: 1. There can be more than one virtual memory chunk. 2. Chunk's base address has a tag. 3. The base address points at the first chunk and thus inherits the tag of the first chunk. 4. The subsequent chunks will be accessed with the tag from the first chunk. 5. Thus, the subsequent chunks need to have their tag set to match that of the first chunk. Refactor code by moving it into a helper in preparation for the actual fix. Link: https://lkml.kernel.org/r/821677dd824d003cc5b7a77891db4723e23518ea.17622670… Link: https://lore.kernel.org/all/e7e04692866d02e6d3b32bb43b998e5d17092ba4.173868… [1] Link: https://lore.kernel.org/all/aMUrW1Znp1GEj7St@MiWiFi-R3L-srv/ [2] Link: https://lore.kernel.org/all/CAPAsAGxDRv_uFeMYu9TwhBVWHCCtkSxoWY4xmFB_vowMbi… [3] Link: https://lore.kernel.org/all/cover.1761763681.git.m.wieczorretman@pm.me/ [4] Fixes: 1d96320f8d53 ("kasan, vmalloc: add vmalloc tagging for SW_TAGS") Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> Tested-by: Baoquan He <bhe(a)redhat.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Marco Elver <elver(a)google.com> Cc: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> [6.1+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/kasan.h | 10 ++++++++++ mm/kasan/common.c | 11 +++++++++++ mm/vmalloc.c | 4 +--- 3 files changed, 22 insertions(+), 3 deletions(-) --- a/include/linux/kasan.h~kasan-unpoison-pcpu-chunks-with-base-address-tag +++ a/include/linux/kasan.h @@ -614,6 +614,13 @@ static __always_inline void kasan_poison __kasan_poison_vmalloc(start, size); } +void __kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms); +static __always_inline void kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms) +{ + if (kasan_enabled()) + __kasan_unpoison_vmap_areas(vms, nr_vms); +} + #else /* CONFIG_KASAN_VMALLOC */ static inline void kasan_populate_early_vm_area_shadow(void *start, @@ -638,6 +645,9 @@ static inline void *kasan_unpoison_vmall static inline void kasan_poison_vmalloc(const void *start, unsigned long size) { } +static inline void kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms) +{ } + #endif /* CONFIG_KASAN_VMALLOC */ #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \ --- a/mm/kasan/common.c~kasan-unpoison-pcpu-chunks-with-base-address-tag +++ a/mm/kasan/common.c @@ -28,6 +28,7 @@ #include <linux/string.h> #include <linux/types.h> #include <linux/bug.h> +#include <linux/vmalloc.h> #include "kasan.h" #include "../slab.h" @@ -582,3 +583,13 @@ bool __kasan_check_byte(const void *addr } return true; } + +void __kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms) +{ + int area; + + for (area = 0 ; area < nr_vms ; area++) { + kasan_poison(vms[area]->addr, vms[area]->size, + arch_kasan_get_tag(vms[area]->addr), false); + } +} --- a/mm/vmalloc.c~kasan-unpoison-pcpu-chunks-with-base-address-tag +++ a/mm/vmalloc.c @@ -4870,9 +4870,7 @@ retry: * With hardware tag-based KASAN, marking is skipped for * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). */ - for (area = 0; area < nr_vms; area++) - vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr, - vms[area]->size, KASAN_VMALLOC_PROT_NORMAL); + kasan_unpoison_vmap_areas(vms, nr_vms); kfree(vas); return vms; _ Patches currently in -mm which might be from maciej.wieczor-retman(a)intel.com are kasan-unpoison-vms-addresses-with-a-common-tag.patch

1 month, 2 weeks

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[PATCH v3] fscrypt: fix left shift underflow when inode->i_blkbits > PAGE_SHIFT

by Eric Biggers

From: Yongpeng Yang <yangyongpeng(a)xiaomi.com> When simulating an nvme device on qemu with both logical_block_size and physical_block_size set to 8 KiB, an error trace appears during partition table reading at boot time. The issue is caused by inode->i_blkbits being larger than PAGE_SHIFT, which leads to a left shift of -1 and triggering a UBSAN warning. [ 2.697306] ------------[ cut here ]------------ [ 2.697309] UBSAN: shift-out-of-bounds in fs/crypto/inline_crypt.c:336:37 [ 2.697311] shift exponent -1 is negative [ 2.697315] CPU: 3 UID: 0 PID: 274 Comm: (udev-worker) Not tainted 6.18.0-rc2+ #34 PREEMPT(voluntary) [ 2.697317] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 2.697320] Call Trace: [ 2.697324] <TASK> [ 2.697325] dump_stack_lvl+0x76/0xa0 [ 2.697340] dump_stack+0x10/0x20 [ 2.697342] __ubsan_handle_shift_out_of_bounds+0x1e3/0x390 [ 2.697351] bh_get_inode_and_lblk_num.cold+0x12/0x94 [ 2.697359] fscrypt_set_bio_crypt_ctx_bh+0x44/0x90 [ 2.697365] submit_bh_wbc+0xb6/0x190 [ 2.697370] block_read_full_folio+0x194/0x270 [ 2.697371] ? __pfx_blkdev_get_block+0x10/0x10 [ 2.697375] ? __pfx_blkdev_read_folio+0x10/0x10 [ 2.697377] blkdev_read_folio+0x18/0x30 [ 2.697379] filemap_read_folio+0x40/0xe0 [ 2.697382] filemap_get_pages+0x5ef/0x7a0 [ 2.697385] ? mmap_region+0x63/0xd0 [ 2.697389] filemap_read+0x11d/0x520 [ 2.697392] blkdev_read_iter+0x7c/0x180 [ 2.697393] vfs_read+0x261/0x390 [ 2.697397] ksys_read+0x71/0xf0 [ 2.697398] __x64_sys_read+0x19/0x30 [ 2.697399] x64_sys_call+0x1e88/0x26a0 [ 2.697405] do_syscall_64+0x80/0x670 [ 2.697410] ? __x64_sys_newfstat+0x15/0x20 [ 2.697414] ? x64_sys_call+0x204a/0x26a0 [ 2.697415] ? do_syscall_64+0xb8/0x670 [ 2.697417] ? irqentry_exit_to_user_mode+0x2e/0x2a0 [ 2.697420] ? irqentry_exit+0x43/0x50 [ 2.697421] ? exc_page_fault+0x90/0x1b0 [ 2.697422] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 2.697425] RIP: 0033:0x75054cba4a06 [ 2.697426] Code: 5d e8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 19 83 e2 39 83 fa 08 75 11 e8 26 ff ff ff 66 0f 1f 44 00 00 48 8b 45 10 0f 05 <48> 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08 [ 2.697427] RSP: 002b:00007fff973723a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 2.697430] RAX: ffffffffffffffda RBX: 00005ea9a2c02760 RCX: 000075054cba4a06 [ 2.697432] RDX: 0000000000002000 RSI: 000075054c190000 RDI: 000000000000001b [ 2.697433] RBP: 00007fff973723c0 R08: 0000000000000000 R09: 0000000000000000 [ 2.697434] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 [ 2.697434] R13: 00005ea9a2c027c0 R14: 00005ea9a2be5608 R15: 00005ea9a2be55f0 [ 2.697436] </TASK> [ 2.697436] ---[ end trace ]--- This situation can happen for block devices because when CONFIG_TRANSPARENT_HUGEPAGE is enabled, the maximum logical_block_size is 64 KiB. set_init_blocksize() then sets the block device inode->i_blkbits to 13, which is within this limit. File I/O does not trigger this problem because for filesystems that do not support the FS_LBS feature, sb_set_blocksize() prevents sb->s_blocksize_bits from being larger than PAGE_SHIFT. During inode allocation, alloc_inode()->inode_init_always() assigns inode->i_blkbits from sb->s_blocksize_bits. Currently, only xfs_fs_type has the FS_LBS flag, and since xfs I/O paths do not reach submit_bh_wbc(), it does not hit the left-shift underflow issue. Signed-off-by: Yongpeng Yang <yangyongpeng(a)xiaomi.com> Fixes: 47dd67532303 ("block/bdev: lift block size restrictions to 64k") Cc: stable(a)vger.kernel.org [EB: use folio_pos() and consolidate the two shifts by i_blkbits] Signed-off-by: Eric Biggers <ebiggers(a)kernel.org> --- This patch is targeting the fscrypt/for-current tree fs/crypto/inline_crypt.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c index 5dee7c498bc8..ed6e926226b5 100644 --- a/fs/crypto/inline_crypt.c +++ b/fs/crypto/inline_crypt.c @@ -331,12 +331,11 @@ static bool bh_get_inode_and_lblk_num(const struct buffer_head *bh, if (!mapping) return false; inode = mapping->host; *inode_ret = inode; - *lblk_num_ret = ((u64)folio->index << (PAGE_SHIFT - inode->i_blkbits)) + - (bh_offset(bh) >> inode->i_blkbits); + *lblk_num_ret = (folio_pos(folio) + bh_offset(bh)) >> inode->i_blkbits; return true; } /** * fscrypt_set_bio_crypt_ctx_bh() - prepare a file contents bio for inline base-commit: 6146a0f1dfae5d37442a9ddcba012add260bceb0 -- 2.51.2

1 month, 2 weeks

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NEW PO 33443 Wednesday, November 5, 2025 at 01:26:03 AM

by Procurement 34870

Hi Stable, Please provide a quote for your products: Include: 1.Pricing (per unit) 2.Delivery cost & timeline 3.Quote expiry date Deadline: October Thanks! Danny Peddinti Noble alliance trade

1 month, 2 weeks

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[PATCH v2 1/1] mm: swap: remove duplicate nr_swap_pages decrement in get_swap_page_of_type()

by Youngjun Park

After commit 4f78252da887, nr_swap_pages is decremented in swap_range_alloc(). Since cluster_alloc_swap_entry() calls swap_range_alloc() internally, the decrement in get_swap_page_of_type() causes double-decrementing. Remove the duplicate decrement. Fixes: 4f78252da887 ("mm: swap: move nr_swap_pages counter decrement from folio_alloc_swap() to swap_range_alloc()") Cc: stable(a)vger.kernel.org # v6.17-rc1 Signed-off-by: Youngjun Park <youngjun.park(a)lge.com> Acked-by: Chris Li <chrisl(a)kernel.org> Reviewed-by: Barry Song <baohua(a)kernel.org> --- v1 -> v2: - Collect Acked-by from Chris - thank you! - Collect Reviewed-by from Barry - thank you! - Link to v1: https://lore.kernel.org/linux-mm/20251101134158.69908-1-youngjun.park@lge.c… mm/swapfile.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 543f303f101d..66a502cd747b 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2020,10 +2020,8 @@ swp_entry_t get_swap_page_of_type(int type) local_lock(&percpu_swap_cluster.lock); offset = cluster_alloc_swap_entry(si, 0, 1); local_unlock(&percpu_swap_cluster.lock); - if (offset) { + if (offset) entry = swp_entry(si->type, offset); - atomic_long_dec(&nr_swap_pages); - } } put_swap_device(si); } -- 2.34.1

1 month, 2 weeks

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+ kasan-unpoison-vms-addresses-with-a-common-tag.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: kasan: unpoison vms[area] addresses with a common tag has been added to the -mm mm-hotfixes-unstable branch. Its filename is kasan-unpoison-vms-addresses-with-a-common-tag.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> Subject: kasan: unpoison vms[area] addresses with a common tag Date: Tue, 04 Nov 2025 14:49:48 +0000 A KASAN tag mismatch, possibly causing a kernel panic, can be observed on systems with a tag-based KASAN enabled and with multiple NUMA nodes. It was reported on arm64 and reproduced on x86. It can be explained in the following points: 1. There can be more than one virtual memory chunk. 2. Chunk's base address has a tag. 3. The base address points at the first chunk and thus inherits the tag of the first chunk. 4. The subsequent chunks will be accessed with the tag from the first chunk. 5. Thus, the subsequent chunks need to have their tag set to match that of the first chunk. Unpoison all vm_structs after allocating them for the percpu allocator. Use the same tag to resolve the pcpu chunk address mismatch. Link: https://lkml.kernel.org/r/cf8fe0ffcdbf54e06d9df26c8473b123c4065f02.17622670… Fixes: 1d96320f8d53 ("kasan, vmalloc: add vmalloc tagging for SW_TAGS") Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> Tested-by: Baoquan He <bhe(a)redhat.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Marco Elver <elver(a)google.com> Cc: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> [6.1+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/kasan/common.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/mm/kasan/common.c~kasan-unpoison-vms-addresses-with-a-common-tag +++ a/mm/kasan/common.c @@ -584,12 +584,20 @@ bool __kasan_check_byte(const void *addr return true; } +/* + * A tag mismatch happens when calculating per-cpu chunk addresses, because + * they all inherit the tag from vms[0]->addr, even when nr_vms is bigger + * than 1. This is a problem because all the vms[]->addr come from separate + * allocations and have different tags so while the calculated address is + * correct the tag isn't. + */ void __kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms) { int area; for (area = 0 ; area < nr_vms ; area++) { kasan_poison(vms[area]->addr, vms[area]->size, - arch_kasan_get_tag(vms[area]->addr), false); + arch_kasan_get_tag(vms[0]->addr), false); + arch_kasan_set_tag(vms[area]->addr, arch_kasan_get_tag(vms[0]->addr)); } } _ Patches currently in -mm which might be from maciej.wieczor-retman(a)intel.com are kasan-unpoison-pcpu-chunks-with-base-address-tag.patch kasan-unpoison-vms-addresses-with-a-common-tag.patch

1 month, 2 weeks

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+ kasan-unpoison-pcpu-chunks-with-base-address-tag.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: kasan: unpoison pcpu chunks with base address tag has been added to the -mm mm-hotfixes-unstable branch. Its filename is kasan-unpoison-pcpu-chunks-with-base-address-tag.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> Subject: kasan: unpoison pcpu chunks with base address tag Date: Tue, 04 Nov 2025 14:49:08 +0000 Patch series "kasan: vmalloc: Fix incorrect tag assignment with multiple vm_structs". A KASAN tag mismatch, possibly resulting in a kernel panic, can be observed on systems with a tag-based KASAN enabled and with multiple NUMA nodes. Initially it was only noticed on x86 [1] but later a similar issue was also reported on arm64 [2]. Specifically the problem is related to how vm_structs interact with pcpu_chunks - both when they are allocated, assigned and when pcpu_chunk addresses are derived. When vm_structs are allocated they are tagged if vmalloc support is enabled along the KASAN mode. Later when first pcpu chunk is allocated it gets its 'base_addr' field set to the first allocated vm_struct. With that it inherits that vm_struct's tag. When pcpu_chunk addresses are later derived (by pcpu_chunk_addr(), for example in pcpu_alloc_noprof()) the base_addr field is used and offsets are added to it. If the initial conditions are satisfied then some of the offsets will point into memory allocated with a different vm_struct. So while the lower bits will get accurately derived the tag bits in the top of the pointer won't match the shadow memory contents. The solution (proposed at v2 of the x86 KASAN series [3]) is to tag the vm_structs the same when allocating them for the per cpu allocator (in pcpu_get_vm_areas()). Originally these patches were part of the x86 KASAN series [4]. This patch (of 2): A KASAN tag mismatch, possibly causing a kernel panic, can be observed on systems with a tag-based KASAN enabled and with multiple NUMA nodes. It was reported on arm64 and reproduced on x86. It can be explained in the following points: 1. There can be more than one virtual memory chunk. 2. Chunk's base address has a tag. 3. The base address points at the first chunk and thus inherits the tag of the first chunk. 4. The subsequent chunks will be accessed with the tag from the first chunk. 5. Thus, the subsequent chunks need to have their tag set to match that of the first chunk. Refactor code by moving it into a helper in preparation for the actual fix. Link: https://lkml.kernel.org/r/821677dd824d003cc5b7a77891db4723e23518ea.17622670… Link: https://lore.kernel.org/all/e7e04692866d02e6d3b32bb43b998e5d17092ba4.173868… [1] Link: https://lore.kernel.org/all/aMUrW1Znp1GEj7St@MiWiFi-R3L-srv/ [2] Link: https://lore.kernel.org/all/CAPAsAGxDRv_uFeMYu9TwhBVWHCCtkSxoWY4xmFB_vowMbi… [3] Link: https://lore.kernel.org/all/cover.1761763681.git.m.wieczorretman@pm.me/ [4] Fixes: 1d96320f8d53 ("kasan, vmalloc: add vmalloc tagging for SW_TAGS") Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman(a)intel.com> Tested-by: Baoquan He <bhe(a)redhat.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Marco Elver <elver(a)google.com> Cc: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> [6.1+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/kasan.h | 10 ++++++++++ mm/kasan/common.c | 11 +++++++++++ mm/vmalloc.c | 4 +--- 3 files changed, 22 insertions(+), 3 deletions(-) --- a/include/linux/kasan.h~kasan-unpoison-pcpu-chunks-with-base-address-tag +++ a/include/linux/kasan.h @@ -614,6 +614,13 @@ static __always_inline void kasan_poison __kasan_poison_vmalloc(start, size); } +void __kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms); +static __always_inline void kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms) +{ + if (kasan_enabled()) + __kasan_unpoison_vmap_areas(vms, nr_vms); +} + #else /* CONFIG_KASAN_VMALLOC */ static inline void kasan_populate_early_vm_area_shadow(void *start, @@ -638,6 +645,9 @@ static inline void *kasan_unpoison_vmall static inline void kasan_poison_vmalloc(const void *start, unsigned long size) { } +static inline void kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms) +{ } + #endif /* CONFIG_KASAN_VMALLOC */ #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \ --- a/mm/kasan/common.c~kasan-unpoison-pcpu-chunks-with-base-address-tag +++ a/mm/kasan/common.c @@ -28,6 +28,7 @@ #include <linux/string.h> #include <linux/types.h> #include <linux/bug.h> +#include <linux/vmalloc.h> #include "kasan.h" #include "../slab.h" @@ -582,3 +583,13 @@ bool __kasan_check_byte(const void *addr } return true; } + +void __kasan_unpoison_vmap_areas(struct vm_struct **vms, int nr_vms) +{ + int area; + + for (area = 0 ; area < nr_vms ; area++) { + kasan_poison(vms[area]->addr, vms[area]->size, + arch_kasan_get_tag(vms[area]->addr), false); + } +} --- a/mm/vmalloc.c~kasan-unpoison-pcpu-chunks-with-base-address-tag +++ a/mm/vmalloc.c @@ -4870,9 +4870,7 @@ retry: * With hardware tag-based KASAN, marking is skipped for * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). */ - for (area = 0; area < nr_vms; area++) - vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr, - vms[area]->size, KASAN_VMALLOC_PROT_NORMAL); + kasan_unpoison_vmap_areas(vms, nr_vms); kfree(vas); return vms; _ Patches currently in -mm which might be from maciej.wieczor-retman(a)intel.com are kasan-unpoison-pcpu-chunks-with-base-address-tag.patch kasan-unpoison-vms-addresses-with-a-common-tag.patch

1 month, 2 weeks

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Final Notice

by Rose

1 month, 2 weeks

1
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[PATCH] btrfs: fix NULL pointer dereference in backup_super_roots()

by Zhen Ni

backup_super_roots() unconditionally dereferences extent_root and csum_root pointers obtained from btrfs_extent_root() and btrfs_csum_root() respectively. These functions can return NULL when the corresponding filesystem trees are unavailable due to corruption or other error conditions. This causes a kernel panic. Add proper NULL checking and skip the backup operations for the unavailable roots. Fixes: 29cbcf401793 ("btrfs: stop accessing ->extent_root directly") Fixes: f7238e509404 ("btrfs: add support for multiple global roots") Cc: stable(a)vger.kernel.org Signed-off-by: Zhen Ni <zhen.ni(a)easystack.cn> --- fs/btrfs/disk-io.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 0aa7e5d1b05f..b54c79a1db14 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1670,18 +1670,22 @@ static void backup_super_roots(struct btrfs_fs_info *info) struct btrfs_root *extent_root = btrfs_extent_root(info, 0); struct btrfs_root *csum_root = btrfs_csum_root(info, 0); - btrfs_set_backup_extent_root(root_backup, - extent_root->node->start); - btrfs_set_backup_extent_root_gen(root_backup, - btrfs_header_generation(extent_root->node)); - btrfs_set_backup_extent_root_level(root_backup, - btrfs_header_level(extent_root->node)); - - btrfs_set_backup_csum_root(root_backup, csum_root->node->start); - btrfs_set_backup_csum_root_gen(root_backup, - btrfs_header_generation(csum_root->node)); - btrfs_set_backup_csum_root_level(root_backup, - btrfs_header_level(csum_root->node)); + if (unlikely(!extent_root || !csum_root)) { + btrfs_warn(info, "failed to get extent or csum root for backup"); + } else { + btrfs_set_backup_extent_root(root_backup, + extent_root->node->start); + btrfs_set_backup_extent_root_gen(root_backup, + btrfs_header_generation(extent_root->node)); + btrfs_set_backup_extent_root_level(root_backup, + btrfs_header_level(extent_root->node)); + + btrfs_set_backup_csum_root(root_backup, csum_root->node->start); + btrfs_set_backup_csum_root_gen(root_backup, + btrfs_header_generation(csum_root->node)); + btrfs_set_backup_csum_root_level(root_backup, + btrfs_header_level(csum_root->node)); + } } /* -- 2.20.1

1 month, 2 weeks

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[PATCH v2] tools/testing/nvdimm: Use per-DIMM device handle

by Alison Schofield

KASAN reports a global-out-of-bounds access when running these nfit tests: clear.sh, pmem-errors.sh, pfn-meta-errors.sh, btt-errors.sh, daxdev-errors.sh, and inject-error.sh. [] BUG: KASAN: global-out-of-bounds in nfit_test_ctl+0x769f/0x7840 [nfit_test] [] Read of size 4 at addr ffffffffc03ea01c by task ndctl/1215 [] The buggy address belongs to the variable: [] handle+0x1c/0x1df4 [nfit_test] nfit_test_search_spa() uses handle[nvdimm->id] to retrieve a device handle and triggers a KASAN error when it reads past the end of the handle array. It should not be indexing the handle array at all. The correct device handle is stored in per-DIMM test data. Each DIMM has a struct nfit_mem that embeds a struct acpi_nfit_memdev that describes the NFIT device handle. Use that device handle here. Fixes: 10246dc84dfc ("acpi nfit: nfit_test supports translate SPA") Cc: <stable(a)vger.kernel.org> Signed-off-by: Alison Schofield <alison.schofield(a)intel.com> --- Changes in v2: - Use the correct handle in per-DIMM test data (Dan) - Update commit message and log - Update Fixes Tag tools/testing/nvdimm/test/nfit.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c index cfd4378e2129..f87e9f251d13 100644 --- a/tools/testing/nvdimm/test/nfit.c +++ b/tools/testing/nvdimm/test/nfit.c @@ -670,6 +670,7 @@ static int nfit_test_search_spa(struct nvdimm_bus *bus, .addr = spa->spa, .region = NULL, }; + struct nfit_mem *nfit_mem; u64 dpa; ret = device_for_each_child(&bus->dev, &ctx, @@ -687,8 +688,12 @@ static int nfit_test_search_spa(struct nvdimm_bus *bus, */ nd_mapping = &nd_region->mapping[nd_region->ndr_mappings - 1]; nvdimm = nd_mapping->nvdimm; + nfit_mem = nvdimm_provider_data(nvdimm); + if (!nfit_mem) + return -EINVAL; - spa->devices[0].nfit_device_handle = handle[nvdimm->id]; + spa->devices[0].nfit_device_handle = + __to_nfit_memdev(nfit_mem)->device_handle; spa->num_nvdimms = 1; spa->devices[0].dpa = dpa; base-commit: 211ddde0823f1442e4ad052a2f30f050145ccada -- 2.37.3

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