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v6.15
24250 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
0f8c0258bf |
22 hotfixes. 13 are cc:stable and the remainder address post-6.14 issues
or aren't considered necessary for -stable kernels. 19 are for MM. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaDLNqwAKCRDdBJ7gKXxA juanAQD4aZn7ACTpbIgDIlLVJouq6OOHEYye9hhxz19UN2mAUgEAn8jPqvBDav3S HxjMFSdgLUQVO03FCs9tpNJchi69nw0= =R3UI -----END PGP SIGNATURE----- Merge tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "22 hotfixes. 13 are cc:stable and the remainder address post-6.14 issues or aren't considered necessary for -stable kernels. 19 are for MM" * tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits) mailmap: add Jarkko's employer email address mm: fix copy_vma() error handling for hugetlb mappings memcg: always call cond_resched() after fn() mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios mm: vmalloc: only zero-init on vrealloc shrink mm: vmalloc: actually use the in-place vrealloc region alloc_tag: allocate percpu counters for module tags dynamically module: release codetag section when module load fails mm/cma: make detection of highmem_start more robust MAINTAINERS: add mm memory policy section MAINTAINERS: add mm ksm section kasan: avoid sleepable page allocation from atomic context highmem: add folio_test_partial_kmap() MAINTAINERS: add hung-task detector section taskstats: fix struct taskstats breaks backward compatibility since version 15 mm/truncate: fix out-of-bounds when doing a right-aligned split MAINTAINERS: add mm reclaim section MAINTAINERS: update page allocator section mm: fix VM_UFFD_MINOR == VM_SHADOW_STACK on USERFAULTFD=y && ARM64_GCS=y mm: mmap: map MAP_STACK to VM_NOHUGEPAGE only if THP is enabled ... |
||
|
Ricardo Cañuelo Navarro
|
ee40c9920a |
mm: fix copy_vma() error handling for hugetlb mappings
If, during a mremap() operation for a hugetlb-backed memory mapping, copy_vma() fails after the source vma has been duplicated and opened (ie. vma_link() fails), the error is handled by closing the new vma. This updates the hugetlbfs reservation counter of the reservation map which at this point is referenced by both the source vma and the new copy. As a result, once the new vma has been freed and copy_vma() returns, the reservation counter for the source vma will be incorrect. This patch addresses this corner case by clearing the hugetlb private page reservation reference for the new vma and decrementing the reference before closing the vma, so that vma_close() won't update the reservation counter. This is also what copy_vma_and_data() does with the source vma if copy_vma() succeeds, so a helper function has been added to do the fixup in both functions. The issue was reported by a private syzbot instance and can be reproduced using the C reproducer in [1]. It's also a possible duplicate of public syzbot report [2]. The WARNING report is: ============================================================ page_counter underflow: -1024 nr_pages=1024 WARNING: CPU: 0 PID: 3287 at mm/page_counter.c:61 page_counter_cancel+0xf6/0x120 Modules linked in: CPU: 0 UID: 0 PID: 3287 Comm: repro__WARNING_ Not tainted 6.15.0-rc7+ #54 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014 RIP: 0010:page_counter_cancel+0xf6/0x120 Code: ff 5b 41 5e 41 5f 5d c3 cc cc cc cc e8 f3 4f 8f ff c6 05 64 01 27 06 01 48 c7 c7 60 15 f8 85 48 89 de 4c 89 fa e8 2a a7 51 ff <0f> 0b e9 66 ff ff ff 44 89 f9 80 e1 07 38 c1 7c 9d 4c 81 RSP: 0018:ffffc900025df6a0 EFLAGS: 00010246 RAX: 2edfc409ebb44e00 RBX: fffffffffffffc00 RCX: ffff8880155f0000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff81c4a23c R09: 1ffff1100330482a R10: dffffc0000000000 R11: ffffed100330482b R12: 0000000000000000 R13: ffff888058a882c0 R14: ffff888058a882c0 R15: 0000000000000400 FS: 0000000000000000(0000) GS:ffff88808fc53000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004b33e0 CR3: 00000000076d6000 CR4: 00000000000006f0 Call Trace: <TASK> page_counter_uncharge+0x33/0x80 hugetlb_cgroup_uncharge_counter+0xcb/0x120 hugetlb_vm_op_close+0x579/0x960 ? __pfx_hugetlb_vm_op_close+0x10/0x10 remove_vma+0x88/0x130 exit_mmap+0x71e/0xe00 ? __pfx_exit_mmap+0x10/0x10 ? __mutex_unlock_slowpath+0x22e/0x7f0 ? __pfx_exit_aio+0x10/0x10 ? __up_read+0x256/0x690 ? uprobe_clear_state+0x274/0x290 ? mm_update_next_owner+0xa9/0x810 __mmput+0xc9/0x370 exit_mm+0x203/0x2f0 ? __pfx_exit_mm+0x10/0x10 ? taskstats_exit+0x32b/0xa60 do_exit+0x921/0x2740 ? do_raw_spin_lock+0x155/0x3b0 ? __pfx_do_exit+0x10/0x10 ? __pfx_do_raw_spin_lock+0x10/0x10 ? _raw_spin_lock_irq+0xc5/0x100 do_group_exit+0x20c/0x2c0 get_signal+0x168c/0x1720 ? __pfx_get_signal+0x10/0x10 ? schedule+0x165/0x360 arch_do_signal_or_restart+0x8e/0x7d0 ? __pfx_arch_do_signal_or_restart+0x10/0x10 ? __pfx___se_sys_futex+0x10/0x10 syscall_exit_to_user_mode+0xb8/0x2c0 do_syscall_64+0x75/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x422dcd Code: Unable to access opcode bytes at 0x422da3. RSP: 002b:00007ff266cdb208 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007ff266cdbcdc RCX: 0000000000422dcd RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000004c7bec RBP: 00007ff266cdb220 R08: 203a6362696c6720 R09: 203a6362696c6720 R10: 0000200000c00000 R11: 0000000000000246 R12: ffffffffffffffd0 R13: 0000000000000002 R14: 00007ffe1cb5f520 R15: 00007ff266cbb000 </TASK> ============================================================ Link: https://lkml.kernel.org/r/20250523-warning_in_page_counter_cancel-v2-1-b6df1a8cfefd@igalia.com Link: https://people.igalia.com/rcn/kernel_logs/20250422__WARNING_in_page_counter_cancel__repro.c [1] Link: https://lore.kernel.org/all/67000a50.050a0220.49194.048d.GAE@google.com/ [2] Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com> Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Florent Revest <revest@google.com> Cc: Jann Horn <jannh@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Breno Leitao
|
06717a7b6c |
memcg: always call cond_resched() after fn()
I am seeing soft lockup on certain machine types when a cgroup OOMs. This
is happening because killing the process in certain machine might be very
slow, which causes the soft lockup and RCU stalls. This happens usually
when the cgroup has MANY processes and memory.oom.group is set.
Example I am seeing in real production:
[462012.244552] Memory cgroup out of memory: Killed process 3370438 (crosvm) ....
....
[462037.318059] Memory cgroup out of memory: Killed process 4171372 (adb) ....
[462037.348314] watchdog: BUG: soft lockup - CPU#64 stuck for 26s! [stat_manager-ag:1618982]
....
Quick look at why this is so slow, it seems to be related to serial flush
for certain machine types. For all the crashes I saw, the target CPU was
at console_flush_all().
In the case above, there are thousands of processes in the cgroup, and it
is soft locking up before it reaches the 1024 limit in the code (which
would call the cond_resched()). So, cond_resched() in 1024 blocks is not
sufficient.
Remove the counter-based conditional rescheduling logic and call
cond_resched() unconditionally after each task iteration, after fn() is
called. This avoids the lockup independently of how slow fn() is.
Link: https://lkml.kernel.org/r/20250523-memcg_fix-v1-1-ad3eafb60477@debian.org
Fixes:
|
||
|
Ge Yang
|
113ed54ad2 |
mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios
A kernel crash was observed when replacing free hugetlb folios:
BUG: kernel NULL pointer dereference, address: 0000000000000028
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 28 UID: 0 PID: 29639 Comm: test_cma.sh Tainted 6.15.0-rc6-zp #41 PREEMPT(voluntary)
RIP: 0010:alloc_and_dissolve_hugetlb_folio+0x1d/0x1f0
RSP: 0018:ffffc9000b30fa90 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000342cca RCX: ffffea0043000000
RDX: ffffc9000b30fb08 RSI: ffffea0043000000 RDI: 0000000000000000
RBP: ffffc9000b30fb20 R08: 0000000000001000 R09: 0000000000000000
R10: ffff88886f92eb00 R11: 0000000000000000 R12: ffffea0043000000
R13: 0000000000000000 R14: 00000000010c0200 R15: 0000000000000004
FS: 00007fcda5f14740(0000) GS:ffff8888ec1d8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 0000000391402000 CR4: 0000000000350ef0
Call Trace:
<TASK>
replace_free_hugepage_folios+0xb6/0x100
alloc_contig_range_noprof+0x18a/0x590
? srso_return_thunk+0x5/0x5f
? down_read+0x12/0xa0
? srso_return_thunk+0x5/0x5f
cma_range_alloc.constprop.0+0x131/0x290
__cma_alloc+0xcf/0x2c0
cma_alloc_write+0x43/0xb0
simple_attr_write_xsigned.constprop.0.isra.0+0xb2/0x110
debugfs_attr_write+0x46/0x70
full_proxy_write+0x62/0xa0
vfs_write+0xf8/0x420
? srso_return_thunk+0x5/0x5f
? filp_flush+0x86/0xa0
? srso_return_thunk+0x5/0x5f
? filp_close+0x1f/0x30
? srso_return_thunk+0x5/0x5f
? do_dup2+0xaf/0x160
? srso_return_thunk+0x5/0x5f
ksys_write+0x65/0xe0
do_syscall_64+0x64/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
There is a potential race between __update_and_free_hugetlb_folio() and
replace_free_hugepage_folios():
CPU1 CPU2
__update_and_free_hugetlb_folio replace_free_hugepage_folios
folio_test_hugetlb(folio)
-- It's still hugetlb folio.
__folio_clear_hugetlb(folio)
hugetlb_free_folio(folio)
h = folio_hstate(folio)
-- Here, h is NULL pointer
When the above race condition occurs, folio_hstate(folio) returns NULL,
and subsequent access to this NULL pointer will cause the system to crash.
To resolve this issue, execute folio_hstate(folio) under the protection
of the hugetlb_lock lock, ensuring that folio_hstate(folio) does not
return NULL.
Link: https://lkml.kernel.org/r/1747884137-26685-1-git-send-email-yangge1116@126.com
Fixes:
|
||
|
Kees Cook
|
70d1eb031a |
mm: vmalloc: only zero-init on vrealloc shrink
The common case is to grow reallocations, and since init_on_alloc will
have already zeroed the whole allocation, we only need to zero when
shrinking the allocation.
Link: https://lkml.kernel.org/r/20250515214217.619685-2-kees@kernel.org
Fixes:
|
||
|
Kees Cook
|
f7a35a3c36 |
mm: vmalloc: actually use the in-place vrealloc region
Patch series "mm: vmalloc: Actually use the in-place vrealloc region".
This fixes a performance regression[1] with vrealloc()[1].
The refactoring to not build a new vmalloc region only actually worked
when shrinking. Actually return the resized area when it grows. Ugh.
Link: https://lkml.kernel.org/r/20250515214217.619685-1-kees@kernel.org
Fixes:
|
||
|
Mike Rapoport (Microsoft)
|
07c9214c79 |
mm/cma: make detection of highmem_start more robust
Pratyush Yadav reports the following crash:
------------[ cut here ]------------
kernel BUG at arch/x86/mm/physaddr.c:23!
ception 0x06 IP 10:ffffffff812ebbf8 error 0 cr2 0xffff88903ffff000
CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.15.0-rc6+ #231 PREEMPT(undef)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
RIP: 0010:__phys_addr+0x58/0x60
Code: 01 48 89 c2 48 d3 ea 48 85 d2 75 05 e9 91 52 cf 00 0f 0b 48 3d ff ff ff 1f 77 0f 48 8b 05 20 54 55 01 48 01 d0 e9 78 52 cf 00 <0f> 0b 90 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffffff82803dd8 EFLAGS: 00010006 ORIG_RAX: 0000000000000000
RAX: 000000007fffffff RBX: 00000000ffffffff RCX: 0000000000000000
RDX: 000000007fffffff RSI: 0000000280000000 RDI: ffffffffffffffff
RBP: ffffffff82803e68 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff83153180 R11: ffffffff82803e48 R12: ffffffff83c9aed0
R13: 0000000000000000 R14: 0000001040000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:0000000000000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88903ffff000 CR3: 0000000002838000 CR4: 00000000000000b0
Call Trace:
<TASK>
? __cma_declare_contiguous_nid+0x6e/0x340
? cma_declare_contiguous_nid+0x33/0x70
? dma_contiguous_reserve_area+0x2f/0x70
? setup_arch+0x6f1/0x870
? start_kernel+0x52/0x4b0
? x86_64_start_reservations+0x29/0x30
? x86_64_start_kernel+0x7c/0x80
? common_startup_64+0x13e/0x141
The reason is that __cma_declare_contiguous_nid() does:
highmem_start = __pa(high_memory - 1) + 1;
If dma_contiguous_reserve_area() (or any other CMA declaration) is
called before free_area_init(), high_memory is uninitialized. Without
CONFIG_DEBUG_VIRTUAL, it will likely work but use the wrong value for
highmem_start.
The issue occurs because commit
|
||
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Alexander Gordeev
|
b6ea95a34c |
kasan: avoid sleepable page allocation from atomic context
apply_to_pte_range() enters the lazy MMU mode and then invokes
kasan_populate_vmalloc_pte() callback on each page table walk iteration.
However, the callback can go into sleep when trying to allocate a single
page, e.g. if an architecutre disables preemption on lazy MMU mode enter.
On s390 if make arch_enter_lazy_mmu_mode() -> preempt_enable() and
arch_leave_lazy_mmu_mode() -> preempt_disable(), such crash occurs:
[ 0.663336] BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:321
[ 0.663348] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2, name: kthreadd
[ 0.663358] preempt_count: 1, expected: 0
[ 0.663366] RCU nest depth: 0, expected: 0
[ 0.663375] no locks held by kthreadd/2.
[ 0.663383] Preemption disabled at:
[ 0.663386] [<0002f3284cbb4eda>] apply_to_pte_range+0xfa/0x4a0
[ 0.663405] CPU: 0 UID: 0 PID: 2 Comm: kthreadd Not tainted 6.15.0-rc5-gcc-kasan-00043-gd76bb1ebb558-dirty #162 PREEMPT
[ 0.663408] Hardware name: IBM 3931 A01 701 (KVM/Linux)
[ 0.663409] Call Trace:
[ 0.663410] [<0002f3284c385f58>] dump_stack_lvl+0xe8/0x140
[ 0.663413] [<0002f3284c507b9e>] __might_resched+0x66e/0x700
[ 0.663415] [<0002f3284cc4f6c0>] __alloc_frozen_pages_noprof+0x370/0x4b0
[ 0.663419] [<0002f3284ccc73c0>] alloc_pages_mpol+0x1a0/0x4a0
[ 0.663421] [<0002f3284ccc8518>] alloc_frozen_pages_noprof+0x88/0xc0
[ 0.663424] [<0002f3284ccc8572>] alloc_pages_noprof+0x22/0x120
[ 0.663427] [<0002f3284cc341ac>] get_free_pages_noprof+0x2c/0xc0
[ 0.663429] [<0002f3284cceba70>] kasan_populate_vmalloc_pte+0x50/0x120
[ 0.663433] [<0002f3284cbb4ef8>] apply_to_pte_range+0x118/0x4a0
[ 0.663435] [<0002f3284cbc7c14>] apply_to_pmd_range+0x194/0x3e0
[ 0.663437] [<0002f3284cbc99be>] __apply_to_page_range+0x2fe/0x7a0
[ 0.663440] [<0002f3284cbc9e88>] apply_to_page_range+0x28/0x40
[ 0.663442] [<0002f3284ccebf12>] kasan_populate_vmalloc+0x82/0xa0
[ 0.663445] [<0002f3284cc1578c>] alloc_vmap_area+0x34c/0xc10
[ 0.663448] [<0002f3284cc1c2a6>] __get_vm_area_node+0x186/0x2a0
[ 0.663451] [<0002f3284cc1e696>] __vmalloc_node_range_noprof+0x116/0x310
[ 0.663454] [<0002f3284cc1d950>] __vmalloc_node_noprof+0xd0/0x110
[ 0.663457] [<0002f3284c454b88>] alloc_thread_stack_node+0xf8/0x330
[ 0.663460] [<0002f3284c458d56>] dup_task_struct+0x66/0x4d0
[ 0.663463] [<0002f3284c45be90>] copy_process+0x280/0x4b90
[ 0.663465] [<0002f3284c460940>] kernel_clone+0xd0/0x4b0
[ 0.663467] [<0002f3284c46115e>] kernel_thread+0xbe/0xe0
[ 0.663469] [<0002f3284c4e440e>] kthreadd+0x50e/0x7f0
[ 0.663472] [<0002f3284c38c04a>] __ret_from_fork+0x8a/0xf0
[ 0.663475] [<0002f3284ed57ff2>] ret_from_fork+0xa/0x38
Instead of allocating single pages per-PTE, bulk-allocate the shadow
memory prior to applying kasan_populate_vmalloc_pte() callback on a page
range.
Link: https://lkml.kernel.org/r/c61d3560297c93ed044f0b1af085610353a06a58.1747316918.git.agordeev@linux.ibm.com
Fixes:
|
||
|
Zhang Yi
|
66f28ffb38 |
mm/truncate: fix out-of-bounds when doing a right-aligned split
When performing a right split on a folio, the split_at2 may point to a
not-present page if the offset + length equals the original folio size,
which will trigger the following error:
BUG: unable to handle page fault for address: ffffea0006000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 143ffb9067 P4D 143ffb9067 PUD 143ffb8067 PMD 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 0 UID: 0 PID: 502640 Comm: fsx Not tainted 6.15.0-rc3-gc6156189fc6b #889 PR
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/4
RIP: 0010:truncate_inode_partial_folio+0x208/0x620
Code: ff 03 48 01 da e8 78 7e 13 00 48 83 05 10 b5 5a 0c 01 85 c0 0f 85 1c 02 001
RSP: 0018:ffffc90005bafab0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffffea0005ffff00 RCX: 0000000000000002
RDX: 000000000000000c RSI: 0000000000013975 RDI: ffffc90005bafa30
RBP: ffffea0006000000 R08: 0000000000000000 R09: 00000000000009bf
R10: 00000000000007e0 R11: 0000000000000000 R12: 0000000000001633
R13: 0000000000000000 R14: ffffea0005ffff00 R15: fffffffffffffffe
FS: 00007f9f9a161740(0000) GS:ffff8894971fd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffea0006000008 CR3: 000000017c2ae000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
truncate_inode_pages_range+0x226/0x720
truncate_pagecache+0x57/0x90
...
Fix this issue by skipping the split if truncation aligns with the folio
size, make sure the split page number lies within the folio.
Link: https://lkml.kernel.org/r/20250512062825.3533342-1-yi.zhang@huaweicloud.com
Fixes:
|
||
|
Tianyang Zhang
|
e05741fb10 |
mm/page_alloc.c: avoid infinite retries caused by cpuset race
__alloc_pages_slowpath has no change detection for ac->nodemask in the
part of retry path, while cpuset can modify it in parallel. For some
processes that set mempolicy as MPOL_BIND, this results ac->nodemask
changes, and then the should_reclaim_retry will judge based on the latest
nodemask and jump to retry, while the get_page_from_freelist only
traverses the zonelist from ac->preferred_zoneref, which selected by a
expired nodemask and may cause infinite retries in some cases
cpu 64:
__alloc_pages_slowpath {
/* ..... */
retry:
/* ac->nodemask = 0x1, ac->preferred->zone->nid = 1 */
if (alloc_flags & ALLOC_KSWAPD)
wake_all_kswapds(order, gfp_mask, ac);
/* cpu 1:
cpuset_write_resmask
update_nodemask
update_nodemasks_hier
update_tasks_nodemask
mpol_rebind_task
mpol_rebind_policy
mpol_rebind_nodemask
// mempolicy->nodes has been modified,
// which ac->nodemask point to
*/
/* ac->nodemask = 0x3, ac->preferred->zone->nid = 1 */
if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
did_some_progress > 0, &no_progress_loops))
goto retry;
}
Simultaneously starting multiple cpuset01 from LTP can quickly reproduce
this issue on a multi node server when the maximum memory pressure is
reached and the swap is enabled
Link: https://lkml.kernel.org/r/20250416082405.20988-1-zhangtianyang@loongson.cn
Fixes:
|
||
|
Linus Torvalds
|
e72e784fb1 |
Nine singleton hotfixes, all MM. Four are cc:stable.
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaCi8agAKCRDdBJ7gKXxA jm01AQCFDY9R8TeT7ppzJcgkLGtV/UdBJG9aiinORBKOmA1sRQD/URnDRJZqjVGO Wtp1RkMJG4+u7OeuTvj9LIhuigJ7uQM= =M3Y/ -----END PGP SIGNATURE----- Merge tag 'mm-hotfixes-stable-2025-05-17-09-41' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "Nine singleton hotfixes, all MM. Four are cc:stable" * tag 'mm-hotfixes-stable-2025-05-17-09-41' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm: userfaultfd: correct dirty flags set for both present and swap pte zsmalloc: don't underflow size calculation in zs_obj_write() mm/page_alloc: fix race condition in unaccepted memory handling mm/page_alloc: ensure try_alloc_pages() plays well with unaccepted memory MAINTAINERS: add mm GUP section mm/codetag: move tag retrieval back upfront in __free_pages() mm/memory: fix mapcount / refcount sanity check for mTHP reuse kernel/fork: only call untrack_pfn_clear() on VMAs duplicated for fork() mm: hugetlb: fix incorrect fallback for subpool |
||
|
Linus Torvalds
|
e238e49b18 |
vfs-6.15-rc7.fixes
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCaCHSPAAKCRCRxhvAZXjc ouxZAQCZcvUr0H7LO9j2JQdM+S7ABLU4T8El/f72tvFfapPJVgEA3zrAQ9qgZacv ytsmniyOnIzGsamPcK8Zy6LP6KjOYQ8= =xEE0 -----END PGP SIGNATURE----- Merge tag 'vfs-6.15-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: - Ensure that simple_xattr_list() always includes security.* xattrs - Fix eventpoll busy loop optimization when combined with timeouts - Disable swapon() for devices with block sizes greater than page sizes - Don't call errseq_set() twice during mark_buffer_write_io_error(). Just use mapping_set_error() which takes care to not deference unconditionally * tag 'vfs-6.15-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: Remove redundant errseq_set call in mark_buffer_write_io_error. swapfile: disable swapon for bs > ps devices fs/eventpoll: fix endless busy loop after timeout has expired fs/xattr.c: fix simple_xattr_list to always include security.* xattrs |
||
|
Barry Song
|
75cb1cca2c |
mm: userfaultfd: correct dirty flags set for both present and swap pte
As David pointed out, what truly matters for mremap and userfaultfd move
operations is the soft dirty bit. The current comment and
implementation—which always sets the dirty bit for present PTEs and
fails to set the soft dirty bit for swap PTEs—are incorrect. This could
break features like Checkpoint-Restore in Userspace (CRIU).
This patch updates the behavior to correctly set the soft dirty bit for
both present and swap PTEs in accordance with mremap.
Link: https://lkml.kernel.org/r/20250508220912.7275-1-21cnbao@gmail.com
Fixes:
|
||
|
Sergey Senozhatsky
|
02f5bf89f0 |
zsmalloc: don't underflow size calculation in zs_obj_write()
Do not mix class->size and object size during offsets/sizes calculation in
zs_obj_write(). Size classes can merge into clusters, based on
objects-per-zspage and pages-per-zspage characteristics, so some size
classes can store objects smaller than class->size. This becomes
problematic when object size is much smaller than class->size. zsmalloc
can falsely decide that object spans two physical pages, because a larger
class->size value is used for that check, while the actual object is much
smaller and fits the free space of the first physical page, so there is
nothing to write to the second page and memcpy() size calculation
underflows.
Unable to handle kernel paging request at virtual address ffffc00081ff4000
pc : __memcpy+0x10/0x24
lr : zs_obj_write+0x1b0/0x1d0 [zsmalloc]
Call trace:
__memcpy+0x10/0x24 (P)
zram_write_page+0x150/0x4fc [zram]
zram_submit_bio+0x5e0/0x6a4 [zram]
__submit_bio+0x168/0x220
submit_bio_noacct_nocheck+0x128/0x2c8
submit_bio_noacct+0x19c/0x2f8
This is mostly seen on system with larger page-sizes, because size class
cluters of such systems hold wider size ranges than on 4K PAGE_SIZE
systems.
Assume a 16K PAGE_SIZE system, a write of 820 bytes object to a 864-bytes
size class at offset 15560. 15560 + 864 is more than 16384 so zsmalloc
attempts to memcpy() it to two physical pages. However, 16384 - 15560 =
824 which is more than 820, so the object in fact doesn't span two
physical pages, and there is no data to write to the second physical page.
We always know the exact size in bytes of the object that we are about to
write (store), so use it instead of class->size.
Link: https://lkml.kernel.org/r/20250507054312.4135983-1-senozhatsky@chromium.org
Fixes:
|
||
|
Kirill A. Shutemov
|
fefc075182 |
mm/page_alloc: fix race condition in unaccepted memory handling
The page allocator tracks the number of zones that have unaccepted memory
using static_branch_enc/dec() and uses that static branch in hot paths to
determine if it needs to deal with unaccepted memory.
Borislav and Thomas pointed out that the tracking is racy: operations on
static_branch are not serialized against adding/removing unaccepted pages
to/from the zone.
Sanity checks inside static_branch machinery detects it:
WARNING: CPU: 0 PID: 10 at kernel/jump_label.c:276 __static_key_slow_dec_cpuslocked+0x8e/0xa0
The comment around the WARN() explains the problem:
/*
* Warn about the '-1' case though; since that means a
* decrement is concurrent with a first (0->1) increment. IOW
* people are trying to disable something that wasn't yet fully
* enabled. This suggests an ordering problem on the user side.
*/
The effect of this static_branch optimization is only visible on
microbenchmark.
Instead of adding more complexity around it, remove it altogether.
Link: https://lkml.kernel.org/r/20250506133207.1009676-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Fixes:
|
||
|
Kirill A. Shutemov
|
23fa022a07 |
mm/page_alloc: ensure try_alloc_pages() plays well with unaccepted memory
try_alloc_pages() will not attempt to allocate memory if the system has
*any* unaccepted memory. Memory is accepted as needed and can remain in
the system indefinitely, causing the interface to always fail.
Rather than immediately giving up, attempt to use already accepted memory
on free lists.
Pass 'alloc_flags' to cond_accept_memory() and do not accept new memory
for ALLOC_TRYLOCK requests.
Found via code inspection - only BPF uses this at present and the
runtime effects are unclear.
Link: https://lkml.kernel.org/r/20250506112509.905147-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Fixes:
|
||
|
David Wang
|
0ae0227fa3 |
mm/codetag: move tag retrieval back upfront in __free_pages()
Commit |
||
|
Kairui Song
|
4b7c0857f8 |
mm/memory: fix mapcount / refcount sanity check for mTHP reuse
The following WARNING was triggered during swap stress test with mTHP
enabled:
[ 6609.335758] ------------[ cut here ]------------
[ 6609.337758] WARNING: CPU: 82 PID: 755116 at mm/memory.c:3794 do_wp_page+0x1084/0x10e0
[ 6609.340922] Modules linked in: zram virtiofs
[ 6609.342699] CPU: 82 UID: 0 PID: 755116 Comm: sh Kdump: loaded Not tainted 6.15.0-rc1+ #1429 PREEMPT(voluntary)
[ 6609.347620] Hardware name: Red Hat KVM/RHEL-AV, BIOS 0.0.0 02/06/2015
[ 6609.349909] RIP: 0010:do_wp_page+0x1084/0x10e0
[ 6609.351532] Code: ff ff 48 c7 c6 80 ba 49 82 4c 89 ef e8 95 fd fe ff 0f 0b bd f5 ff ff ff e9 43 fb ff ff 41 83 a9 bc 12 00 00 01 e9 5c fb ff ff <0f> 0b e9 a6 fc ff ff 65 ff 00 f0 48 0f b
a 6d 00 1f 0f 83 82 fc ff
[ 6609.357959] RSP: 0000:ffffc90002273d40 EFLAGS: 00010287
[ 6609.359915] RAX: 000000000000000f RBX: 0000000000000000 RCX: 000fffffffe00000
[ 6609.362606] RDX: 0000000000000010 RSI: 000055a119ac1000 RDI: ffffea000ae6ec00
[ 6609.365143] RBP: ffffea000ae6ec68 R08: 84000002b9bb1025 R09: 000055a119ab6000
[ 6609.367569] R10: ffff8881caa2ad80 R11: 0000000000000000 R12: ffff8881caa2ad80
[ 6609.370255] R13: ffffea000ae6ec00 R14: 000055a119ac1c9c R15: ffffc90002273dd8
[ 6609.373007] FS: 00007f08e467f740(0000) GS:ffff88a07c214000(0000) knlGS:0000000000000000
[ 6609.375999] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6609.377946] CR2: 000055a119ac1c9c CR3: 00000001adfd6005 CR4: 0000000000770eb0
[ 6609.380376] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 6609.382853] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 6609.385216] PKRU: 55555554
[ 6609.386141] Call Trace:
[ 6609.387017] <TASK>
[ 6609.387718] ? ___pte_offset_map+0x1b/0x110
[ 6609.389056] __handle_mm_fault+0xa51/0xf00
[ 6609.390363] ? exc_page_fault+0x6a/0x140
[ 6609.391629] handle_mm_fault+0x13d/0x360
[ 6609.392856] do_user_addr_fault+0x2f2/0x7f0
[ 6609.394160] ? sigprocmask+0x77/0xa0
[ 6609.395375] exc_page_fault+0x6a/0x140
[ 6609.396735] asm_exc_page_fault+0x26/0x30
[ 6609.398224] RIP: 0033:0x55a1050bc18b
[ 6609.399567] Code: 8b 3f 4d 85 ff 74 40 41 39 5f 18 75 f2 49 8b 7f 08 44 38 27 75 e9 4c 89 c6 4c 89 45 c8 e8 bd 83 fa ff 4c 8b 45 c8 85 c0 75 d5 <41> 83 47 1c 01 48 83 c4 28 4c 89 f8 5b 4
1 5c 41 5d 41 5e 41 5f 5d
[ 6609.405971] RSP: 002b:00007ffcf5f37d90 EFLAGS: 00010246
[ 6609.407737] RAX: 0000000000000000 RBX: 00000000182768fa RCX: 0000000000000000
[ 6609.410151] RDX: 00000000000000fa RSI: 000055a105175c7b RDI: 000055a119ac1c60
[ 6609.412606] RBP: 00007ffcf5f37de0 R08: 000055a105175c7b R09: 0000000000000000
[ 6609.414998] R10: 000000004d2dfb5a R11: 0000000000000246 R12: 0000000000000050
[ 6609.417193] R13: 00000000000000fa R14: 000055a119abaf60 R15: 000055a119ac1c80
[ 6609.419268] </TASK>
[ 6609.419928] ---[ end trace 0000000000000000 ]---
The WARN_ON here is simply incorrect. The refcount here must be at least
the mapcount, not the opposite. Each mapcount must have a corresponding
refcount, but the refcount may increase if other components grab the
folio, which is acceptable. Meanwhile, having a mapcount larger than
refcount is a real problem.
So fix the WARN_ON condition.
Link: https://lkml.kernel.org/r/20250425074325.61833-1-ryncsn@gmail.com
Fixes:
|
||
|
Wupeng Ma
|
a833a693a4 |
mm: hugetlb: fix incorrect fallback for subpool
During our testing with hugetlb subpool enabled, we observe that
hstate->resv_huge_pages may underflow into negative values. Root cause
analysis reveals a race condition in subpool reservation fallback handling
as follow:
hugetlb_reserve_pages()
/* Attempt subpool reservation */
gbl_reserve = hugepage_subpool_get_pages(spool, chg);
/* Global reservation may fail after subpool allocation */
if (hugetlb_acct_memory(h, gbl_reserve) < 0)
goto out_put_pages;
out_put_pages:
/* This incorrectly restores reservation to subpool */
hugepage_subpool_put_pages(spool, chg);
When hugetlb_acct_memory() fails after subpool allocation, the current
implementation over-commits subpool reservations by returning the full
'chg' value instead of the actual allocated 'gbl_reserve' amount. This
discrepancy propagates to global reservations during subsequent releases,
eventually causing resv_huge_pages underflow.
This problem can be trigger easily with the following steps:
1. reverse hugepage for hugeltb allocation
2. mount hugetlbfs with min_size to enable hugetlb subpool
3. alloc hugepages with two task(make sure the second will fail due to
insufficient amount of hugepages)
4. with for a few seconds and repeat step 3 which will make
hstate->resv_huge_pages to go below zero.
To fix this problem, return corrent amount of pages to subpool during the
fallback after hugepage_subpool_get_pages is called.
Link: https://lkml.kernel.org/r/20250410062633.3102457-1-mawupeng1@huawei.com
Fixes:
|
||
|
Linus Torvalds
|
6f5bf947ba |
* Mitigate Indirect Target Selection (ITS) issue
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Merge tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 ITS mitigation from Dave Hansen:
"Mitigate Indirect Target Selection (ITS) issue.
I'd describe this one as a good old CPU bug where the behavior is
_obviously_ wrong, but since it just results in bad predictions it
wasn't wrong enough to notice. Well, the researchers noticed and also
realized that thus bug undermined a bunch of existing indirect branch
mitigations.
Thus the unusually wide impact on this one. Details:
ITS is a bug in some Intel CPUs that affects indirect branches
including RETs in the first half of a cacheline. Due to ITS such
branches may get wrongly predicted to a target of (direct or indirect)
branch that is located in the second half of a cacheline. Researchers
at VUSec found this behavior and reported to Intel.
Affected processors:
- Cascade Lake, Cooper Lake, Whiskey Lake V, Coffee Lake R, Comet
Lake, Ice Lake, Tiger Lake and Rocket Lake.
Scope of impact:
- Guest/host isolation:
When eIBRS is used for guest/host isolation, the indirect branches
in the VMM may still be predicted with targets corresponding to
direct branches in the guest.
- Intra-mode using cBPF:
cBPF can be used to poison the branch history to exploit ITS.
Realigning the indirect branches and RETs mitigates this attack
vector.
- User/kernel:
With eIBRS enabled user/kernel isolation is *not* impacted by ITS.
- Indirect Branch Prediction Barrier (IBPB):
Due to this bug indirect branches may be predicted with targets
corresponding to direct branches which were executed prior to IBPB.
This will be fixed in the microcode.
Mitigation:
As indirect branches in the first half of cacheline are affected, the
mitigation is to replace those indirect branches with a call to thunk that
is aligned to the second half of the cacheline.
RETs that take prediction from RSB are not affected, but they may be
affected by RSB-underflow condition. So, RETs in the first half of
cacheline are also patched to a return thunk that executes the RET aligned
to second half of cacheline"
* tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
selftest/x86/bugs: Add selftests for ITS
x86/its: FineIBT-paranoid vs ITS
x86/its: Use dynamic thunks for indirect branches
x86/ibt: Keep IBT disabled during alternative patching
mm/execmem: Unify early execmem_cache behaviour
x86/its: Align RETs in BHB clear sequence to avoid thunking
x86/its: Add support for RSB stuffing mitigation
x86/its: Add "vmexit" option to skip mitigation on some CPUs
x86/its: Enable Indirect Target Selection mitigation
x86/its: Add support for ITS-safe return thunk
x86/its: Add support for ITS-safe indirect thunk
x86/its: Enumerate Indirect Target Selection (ITS) bug
Documentation: x86/bugs/its: Add ITS documentation
|
||
|
Linus Torvalds
|
f717acc6e9 |
memblock fixes for v6.15-rc6
* Mark set_high_memory() as __init to fix section mismatch * Accept memory allocated in memblock_double_array() to mitigate crash of SNP guests -----BEGIN PGP SIGNATURE----- iQFEBAABCgAuFiEEeOVYVaWZL5900a/pOQOGJssO/ZEFAmggNRQQHHJwcHRAa2Vy bmVsLm9yZwAKCRA5A4Ymyw79kXrCCACyy+Q+LakMWEeq4hzbYJUtyEGzSAZgYm4j YX/fW1zgxiYgQHeYJI0fFt9RGMpbT62KWF/43sAS9HnucNWwVZKGVPct00JKe2Eb aDMmU3HuoILuTxF1D1h3eFzX3yyM9bVIUZBOiJqzVlYH5i6NHydGhBaGFL4EZWV5 65z2pA/6nS3pNFc564T25su3gK/J/i5aYXpqhn6MHwY7QIbQhPndNu5k+UuoIQI+ Cbk0dxgx5hvJZJ45SpGuTzCx/Di6GWMRGl4XJD7VX3uJi4FrDjPEfyT6j39qtpLx RsuiS/9iG4Y0ew1bAnQrCNlTTS/HInWJ6yV4ggdy/Cu2j/Qv7kLr =CLPd -----END PGP SIGNATURE----- Merge tag 'fixes-2025-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock Pull memblock fixes from Mike Rapoport: - Mark set_high_memory() as __init to fix section mismatch - Accept memory allocated in memblock_double_array() to mitigate crash of SNP guests * tag 'fixes-2025-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock: Accept allocated memory before use in memblock_double_array() mm,mm_init: Mark set_high_memory as __init |
||
|
Peter Zijlstra
|
d6d1e3e658 |
mm/execmem: Unify early execmem_cache behaviour
Early kernel memory is RWX, only at the end of early boot (before SMP) do we mark things ROX. Have execmem_cache mirror this behaviour for early users. This avoids having to remember what code is execmem and what is not -- we can poke everything with impunity ;-) Also performance for not having to do endless text_poke_mm switches. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> |
||
|
Tom Lendacky
|
da8bf5daa5 |
memblock: Accept allocated memory before use in memblock_double_array()
When increasing the array size in memblock_double_array() and the slab
is not yet available, a call to memblock_find_in_range() is used to
reserve/allocate memory. However, the range returned may not have been
accepted, which can result in a crash when booting an SNP guest:
RIP: 0010:memcpy_orig+0x68/0x130
Code: ...
RSP: 0000:ffffffff9cc03ce8 EFLAGS: 00010006
RAX: ff11001ff83e5000 RBX: 0000000000000000 RCX: fffffffffffff000
RDX: 0000000000000bc0 RSI: ffffffff9dba8860 RDI: ff11001ff83e5c00
RBP: 0000000000002000 R08: 0000000000000000 R09: 0000000000002000
R10: 000000207fffe000 R11: 0000040000000000 R12: ffffffff9d06ef78
R13: ff11001ff83e5000 R14: ffffffff9dba7c60 R15: 0000000000000c00
memblock_double_array+0xff/0x310
memblock_add_range+0x1fb/0x2f0
memblock_reserve+0x4f/0xa0
memblock_alloc_range_nid+0xac/0x130
memblock_alloc_internal+0x53/0xc0
memblock_alloc_try_nid+0x3d/0xa0
swiotlb_init_remap+0x149/0x2f0
mem_init+0xb/0xb0
mm_core_init+0x8f/0x350
start_kernel+0x17e/0x5d0
x86_64_start_reservations+0x14/0x30
x86_64_start_kernel+0x92/0xa0
secondary_startup_64_no_verify+0x194/0x19b
Mitigate this by calling accept_memory() on the memory range returned
before the slab is available.
Prior to v6.12, the accept_memory() interface used a 'start' and 'end'
parameter instead of 'start' and 'size', therefore the accept_memory()
call must be adjusted to specify 'start + size' for 'end' when applying
to kernels prior to v6.12.
Cc: stable@vger.kernel.org # see patch description, needs adjustments for <= 6.11
Fixes:
|
||
|
Petr Vaněk
|
7b08b74f3d |
mm: fix folio_pte_batch() on XEN PV
On XEN PV, folio_pte_batch() can incorrectly batch beyond the end of a
folio due to a corner case in pte_advance_pfn(). Specifically, when the
PFN following the folio maps to an invalidated MFN,
expected_pte = pte_advance_pfn(expected_pte, nr);
produces a pte_none(). If the actual next PTE in memory is also
pte_none(), the pte_same() succeeds,
if (!pte_same(pte, expected_pte))
break;
the loop is not broken, and batching continues into unrelated memory.
For example, with a 4-page folio, the PTE layout might look like this:
[ 53.465673] [ T2552] folio_pte_batch: printing PTE values at addr=0x7f1ac9dc5000
[ 53.465674] [ T2552] PTE[453] = 000000010085c125
[ 53.465679] [ T2552] PTE[454] = 000000010085d125
[ 53.465682] [ T2552] PTE[455] = 000000010085e125
[ 53.465684] [ T2552] PTE[456] = 000000010085f125
[ 53.465686] [ T2552] PTE[457] = 0000000000000000 <-- not present
[ 53.465689] [ T2552] PTE[458] = 0000000101da7125
pte_advance_pfn(PTE[456]) returns a pte_none() due to invalid PFN->MFN
mapping. The next actual PTE (PTE[457]) is also pte_none(), so the loop
continues and includes PTE[457] in the batch, resulting in 5 batched
entries for a 4-page folio. This triggers the following warning:
[ 53.465751] [ T2552] page: refcount:85 mapcount:20 mapping:ffff88813ff4f6a8 index:0x110 pfn:0x10085c
[ 53.465754] [ T2552] head: order:2 mapcount:80 entire_mapcount:0 nr_pages_mapped:4 pincount:0
[ 53.465756] [ T2552] memcg:ffff888003573000
[ 53.465758] [ T2552] aops:0xffffffff8226fd20 ino:82467c dentry name(?):"libc.so.6"
[ 53.465761] [ T2552] flags: 0x2000000000416c(referenced|uptodate|lru|active|private|head|node=0|zone=2)
[ 53.465764] [ T2552] raw: 002000000000416c ffffea0004021f08 ffffea0004021908 ffff88813ff4f6a8
[ 53.465767] [ T2552] raw: 0000000000000110 ffff888133d8bd40 0000005500000013 ffff888003573000
[ 53.465768] [ T2552] head: 002000000000416c ffffea0004021f08 ffffea0004021908 ffff88813ff4f6a8
[ 53.465770] [ T2552] head: 0000000000000110 ffff888133d8bd40 0000005500000013 ffff888003573000
[ 53.465772] [ T2552] head: 0020000000000202 ffffea0004021701 000000040000004f 00000000ffffffff
[ 53.465774] [ T2552] head: 0000000300000003 8000000300000002 0000000000000013 0000000000000004
[ 53.465775] [ T2552] page dumped because: VM_WARN_ON_FOLIO((_Generic((page + nr_pages - 1), const struct page *: (const struct folio *)_compound_head(page + nr_pages - 1), struct page *: (struct folio *)_compound_head(page + nr_pages - 1))) != folio)
Original code works as expected everywhere, except on XEN PV, where
pte_advance_pfn() can yield a pte_none() after balloon inflation due to
MFNs invalidation. In XEN, pte_advance_pfn() ends up calling
__pte()->xen_make_pte()->pte_pfn_to_mfn(), which returns pte_none() when
mfn == INVALID_P2M_ENTRY.
The pte_pfn_to_mfn() documents that nastiness:
If there's no mfn for the pfn, then just create an
empty non-present pte. Unfortunately this loses
information about the original pfn, so
pte_mfn_to_pfn is asymmetric.
While such hacks should certainly be removed, we can do better in
folio_pte_batch() and simply check ahead of time how many PTEs we can
possibly batch in our folio.
This way, we can not only fix the issue but cleanup the code: removing the
pte_pfn() check inside the loop body and avoiding end_ptr comparison +
arithmetic.
Link: https://lkml.kernel.org/r/20250502215019.822-2-arkamar@atlas.cz
Fixes:
|
||
|
Frank van der Linden
|
dac2a4f663 |
mm/hugetlb: copy the CMA flag when demoting
Since commit |
||
|
Kairui Song
|
9a9794a81a |
mm, swap: fix false warning for large allocation with !THP_SWAP
The !CONFIG_THP_SWAP check existed before just fine because slot cache
would reject high order allocation and let the caller split all folios and
try again.
But slot cache is gone, so large allocation will directly go to the
allocator, and the allocator should just fail silently to inform caller to
do the folio split, this is totally fine and expected.
Remove this meaningless warning.
Link: https://lkml.kernel.org/r/20250429094803.85518-1-ryncsn@gmail.com
Fixes:
|
||
|
Kees Cook
|
a0309faf1c |
mm: vmalloc: support more granular vrealloc() sizing
Introduce struct vm_struct::requested_size so that the requested
(re)allocation size is retained separately from the allocated area size.
This means that KASAN will correctly poison the correct spans of requested
bytes. This also means we can support growing the usable portion of an
allocation that can already be supported by the existing area's existing
allocation.
Link: https://lkml.kernel.org/r/20250426001105.it.679-kees@kernel.org
Fixes:
|
||
|
Gavin Guo
|
be6e843fc5 |
mm/huge_memory: fix dereferencing invalid pmd migration entry
When migrating a THP, concurrent access to the PMD migration entry during
a deferred split scan can lead to an invalid address access, as
illustrated below. To prevent this invalid access, it is necessary to
check the PMD migration entry and return early. In this context, there is
no need to use pmd_to_swp_entry and pfn_swap_entry_to_page to verify the
equality of the target folio. Since the PMD migration entry is locked, it
cannot be served as the target.
Mailing list discussion and explanation from Hugh Dickins: "An anon_vma
lookup points to a location which may contain the folio of interest, but
might instead contain another folio: and weeding out those other folios is
precisely what the "folio != pmd_folio((*pmd)" check (and the "risk of
replacing the wrong folio" comment a few lines above it) is for."
BUG: unable to handle page fault for address: ffffea60001db008
CPU: 0 UID: 0 PID: 2199114 Comm: tee Not tainted 6.14.0+ #4 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:split_huge_pmd_locked+0x3b5/0x2b60
Call Trace:
<TASK>
try_to_migrate_one+0x28c/0x3730
rmap_walk_anon+0x4f6/0x770
unmap_folio+0x196/0x1f0
split_huge_page_to_list_to_order+0x9f6/0x1560
deferred_split_scan+0xac5/0x12a0
shrinker_debugfs_scan_write+0x376/0x470
full_proxy_write+0x15c/0x220
vfs_write+0x2fc/0xcb0
ksys_write+0x146/0x250
do_syscall_64+0x6a/0x120
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The bug is found by syzkaller on an internal kernel, then confirmed on
upstream.
Link: https://lkml.kernel.org/r/20250421113536.3682201-1-gavinguo@igalia.com
Link: https://lore.kernel.org/all/20250414072737.1698513-1-gavinguo@igalia.com/
Link: https://lore.kernel.org/all/20250418085802.2973519-1-gavinguo@igalia.com/
Fixes:
|
||
|
Oscar Salvador
|
42e31f0daf |
mm,mm_init: Mark set_high_memory as __init
set_high_memory() touches arch_zone_lowest_possible_pfn which is marked as __initdata, which creates a section mismatch. Since the only user of the function is free_area_init() which is also marked as __init, mark set_high_memory() as __init as well. Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202505060901.Qcs06UoB-lkp@intel.com/ Link: https://lore.kernel.org/r/20250506111012.108743-1-osalvador@suse.de Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> |
||
|
Luis Chamberlain
|
6ba0982c32
|
swapfile: disable swapon for bs > ps devices
Devices which have a requirement for bs > ps cannot be supported for swap as swap still needs work. Now that the block device cache sets the min order for block devices we need this stop gap otherwise all swap operations are rejected. Without this you'll end up with errors on these devices as the swap code still needs much love to support min order. With this we at least now put a stop gap of its use, until the swap subsystem completes its major overhaul: mkswap: /dev/nvme3n1: warning: wiping old swap signature. Setting up swapspace version 1, size = 100 GiB (107374178304 bytes) no label, UUID=6af76b5c-7e7b-4902-b7f7-4c24dde6fa36 swapon: /dev/nvme3n1: swapon failed: Invalid argument Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/aBkS926thy9zvdZb@bombadil.infradead.org Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Linus Torvalds
|
9910affec3 |
slab fix for 6.15-rc5
-----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEe7vIQRWZI0iWSE3xu+CwddJFiJoFAmgUba8ACgkQu+CwddJF iJozDgf/WLyFGYOAIR01wWo29FMvZdYyTqhxwOQn67Q8BMNXo/9nKPlBR7j7vgb3 A2tbc18Up4e2R6/UHH4VbkLIV5e1ejXXRnyfuFyRfAYPQ6KitY0sCAWmMIRPV1Rv kh6nwaxT+gvs3ktBozL+AnXzrKUBURvrCADi2mvNgPIx9UOZBk53rkgPoOIY3y+G Qkl8zTt0sMq0YFlGUj55IQQrIjVIFTIJPMfdcL11MRGrsRA+Qz7h5NaIcb84miX5 oDfwWbAuCIVeT8gDdtkT4bOU0dBJCdEGIL7pu3cySiAoPGnAFb7xg+zXDs9E03fQ /NYAH1lLCW9e6AXiNFQxXuHFb3fXhw== =MQMk -----END PGP SIGNATURE----- Merge tag 'slab-for-6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fix from Vlastimil Babka: - Stable fix to avoid bugs due to leftover obj_ext after allocation profiling is disabled at runtime (Zhenhua Huang) * tag 'slab-for-6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm, slab: clean up slab->obj_exts always |
||
|
Linus Torvalds
|
4b5256f990 |
memblock: fixes for nid setting in memmap_init_reserved_pages()
* pass 'size' rather than 'end' to memblock_set_node() as that function
expects
* fix a corner case when memblock.reserved is doubled at
memmap_init_reserved_pages() and the newly reserved block won't have nid
assigned
-----BEGIN PGP SIGNATURE-----
iQFEBAABCgAuFiEEeOVYVaWZL5900a/pOQOGJssO/ZEFAmgQcBAQHHJwcHRAa2Vy
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PjJ+LHPXswQ5AA3v7cioXhlXF1+sqOUx+Hy4ZPmk+UCAJhAtVv7nj2V7t+F9QHM/
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vK4ygu70rI/Yi/IuxDitw4UV2k3wdep8jWdCnQWe0+qzpft5KY3kozylJQUK6k8k
TOjjm/1EJa3P4bwzmBdkz86eYLGinfuB3Y0XK7oY6Ji5QKKMNvOsJC0hO2dQMQ1n
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=T4cO
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Merge tag 'fixes-2025-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock fixes from Mike Rapoport:
"Fixes for nid setting in memmap_init_reserved_pages():
- pass 'size' rather than 'end' to memblock_set_node() as that
function expects
- fix a corner case when memblock.reserved is doubled at
memmap_init_reserved_pages() and the newly reserved block
won't have nid assigned"
* tag 'fixes-2025-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
memblock tests: add test for memblock_set_node
mm/memblock: repeat setting reserved region nid if array is doubled
mm/memblock: pass size instead of end to memblock_set_node()
|
||
|
Zhenhua Huang
|
be8250786c |
mm, slab: clean up slab->obj_exts always
When memory allocation profiling is disabled at runtime or due to an
error, shutdown_mem_profiling() is called: slab->obj_exts which
previously allocated remains.
It won't be cleared by unaccount_slab() because of
mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts
should always be cleaned up in unaccount_slab() to avoid following error:
[...]BUG: Bad page state in process...
..
[...]page dumped because: page still charged to cgroup
[andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]
Fixes:
|
||
|
Davidlohr Bueso
|
2d900efff9
|
mm/migrate: fix sleep in atomic for large folios and buffer heads
The large folio + buffer head noref migration scenarios are being naughty and blocking while holding a spinlock. As a consequence of the pagecache lookup path taking the folio lock this serializes against migration paths, so they can wait for each other. For the private_lock atomic case, a new BH_Migrate flag is introduced which enables the lookup to bail. This allows the critical region of the private_lock on the migration path to be reduced to the way it was before |
||
|
Linus Torvalds
|
6fea5fabd3 |
16 hotfixes. 2 are cc:stable and the remainder address post-6.14 issues
or aren't considered necessary for -stable kernels. All patches are basically for MM although five are alterations to MAINTAINERS. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaAR3JgAKCRDdBJ7gKXxA jtmLAP9d1h4Y7BnjJ876oPm8s3GQoasiAP6AJw3hbK7rX880vwD8DqU1IM3bTBDu Z9ro41MvytxWKRMEaaYUMcrh04l1IQk= =Fcx+ -----END PGP SIGNATURE----- Merge tag 'mm-hotfixes-stable-2025-04-19-21-24' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc hotfixes from Andrew Morton: "16 hotfixes. 2 are cc:stable and the remainder address post-6.14 issues or aren't considered necessary for -stable kernels. All patches are basically for MM although five are alterations to MAINTAINERS" [ Basic counting skills are clearly not a strictly necessary requirement for kernel maintainers. - Linus ] * tag 'mm-hotfixes-stable-2025-04-19-21-24' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: MAINTAINERS: add section for locking of mm's and VMAs mm: vmscan: fix kswapd exit condition in defrag_mode mm: vmscan: restore high-cpu watermark safety in kswapd MAINTAINERS: add Pedro as reviewer to the MEMORY MAPPING section mm/memory: move sanity checks in do_wp_page() after mapcount vs. refcount stabilization mm, hugetlb: increment the number of pages to be reset on HVO writeback: fix false warning in inode_to_wb() docs: ABI: replace mcroce@microsoft.com with new Meta address mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable() MAINTAINERS: add memory advice section MAINTAINERS: add mmap trace events to MEMORY MAPPING mm: memcontrol: fix swap counter leak from offline cgroup MAINTAINERS: add MM subsection for the page allocator MAINTAINERS: update SLAB ALLOCATOR maintainers fs/dax: fix folio splitting issue by resetting old folio order + _nr_pages mm/page_alloc: fix deadlock on cpu_hotplug_lock in __accept_page() |
||
|
Linus Torvalds
|
3bf8a4598f |
hardening fixes for v6.15-rc3
- lib/prime_numbers: KUnit test should not select PRIME_NUMBERS (Geert Uytterhoeven) - ubsan: Fix panic from test_ubsan_out_of_bounds (Mostafa Saleh) - ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP (Nathan Chancellor) - string: Add load_unaligned_zeropad() code path to sized_strscpy() (Peter Collingbourne) - kasan: Add strscpy() test to trigger tag fault on arm64 (Vincenzo Frascino) - Disable GCC randstruct for COMPILE_TEST -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRSPkdeREjth1dHnSE2KwveOeQkuwUCaAKv9QAKCRA2KwveOeQk u160AP90D0BTkrwYIt1oRMOlN0LX0oipfFDiOKrxuZpgfwqYgwD/XHlTCglva+Kl 1Y0T/wUpA4tL8XoKtcs/kBzsWNyI6wU= =4ji5 -----END PGP SIGNATURE----- Merge tag 'hardening-v6.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening fixes from Kees Cook: - lib/prime_numbers: KUnit test should not select PRIME_NUMBERS (Geert Uytterhoeven) - ubsan: Fix panic from test_ubsan_out_of_bounds (Mostafa Saleh) - ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP (Nathan Chancellor) - string: Add load_unaligned_zeropad() code path to sized_strscpy() (Peter Collingbourne) - kasan: Add strscpy() test to trigger tag fault on arm64 (Vincenzo Frascino) - Disable GCC randstruct for COMPILE_TEST * tag 'hardening-v6.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: lib/prime_numbers: KUnit test should not select PRIME_NUMBERS ubsan: Fix panic from test_ubsan_out_of_bounds lib/Kconfig.ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP hardening: Disable GCC randstruct for COMPILE_TEST kasan: Add strscpy() test to trigger tag fault on arm64 string: Add load_unaligned_zeropad() code path to sized_strscpy() |
||
|
Johannes Weiner
|
a1f0220f33 |
mm: vmscan: fix kswapd exit condition in defrag_mode
Vlastimil points out an issue with kswapd in defrag_mode not waking up
kcompactd reliably.
Background: When kswapd is woken for any higher-order request, it
initially checks those high-order watermarks to decide if work is
necesary. However, it cannot (efficiently) meet the contiguity goal of
such a request by itself. So once it has reclaimed a compaction gap, it
adjusts the request down to check for free order-0 pages, then wakes
kcompactd to coalesce them into larger blocks.
In defrag_mode, the initial watermark check needs to be analogously
against free pageblocks. However, once kswapd drops the high-order to
hand off contiguity work, it also needs to fall back to base page
watermarks - otherwise it'll keep reclaiming until blocks are freed.
While it appears kcompactd is woken up frequently enough to do most of the
compaction work, kswapd ends up overreclaiming by quite a bit:
DEFRAGMODE DEFRAGMODE-thispatch
Hugealloc Time mean 79381.34 ( +0.00%) 88126.12 ( +11.02%)
Hugealloc Time stddev 85852.16 ( +0.00%) 135366.75 ( +57.67%)
Kbuild Real time 249.35 ( +0.00%) 226.71 ( -9.04%)
Kbuild User time 1249.16 ( +0.00%) 1249.37 ( +0.02%)
Kbuild System time 171.76 ( +0.00%) 166.93 ( -2.79%)
THP fault alloc 51666.87 ( +0.00%) 52685.60 ( +1.97%)
THP fault fallback 16970.00 ( +0.00%) 15951.87 ( -6.00%)
Direct compact fail 166.53 ( +0.00%) 178.93 ( +7.40%)
Direct compact success 17.13 ( +0.00%) 4.13 ( -71.69%)
Compact daemon scanned migrate 3095413.33 ( +0.00%) 9231239.53 ( +198.22%)
Compact daemon scanned free 2155966.53 ( +0.00%) 7053692.87 ( +227.17%)
Compact direct scanned migrate 265642.47 ( +0.00%) 68388.33 ( -74.26%)
Compact direct scanned free 130252.60 ( +0.00%) 55634.87 ( -57.29%)
Compact total migrate scanned 3361055.80 ( +0.00%) 9299627.87 ( +176.69%)
Compact total free scanned 2286219.13 ( +0.00%) 7109327.73 ( +210.96%)
Alloc stall 1890.80 ( +0.00%) 6297.60 ( +232.94%)
Pages kswapd scanned 9043558.80 ( +0.00%) 5952576.73 ( -34.18%)
Pages kswapd reclaimed 1891708.67 ( +0.00%) 1030645.00 ( -45.52%)
Pages direct scanned 1017090.60 ( +0.00%) 2688047.60 ( +164.29%)
Pages direct reclaimed 92682.60 ( +0.00%) 309770.53 ( +234.22%)
Pages total scanned 10060649.40 ( +0.00%) 8640624.33 ( -14.11%)
Pages total reclaimed 1984391.27 ( +0.00%) 1340415.53 ( -32.45%)
Swap out 884585.73 ( +0.00%) 417781.93 ( -52.77%)
Swap in 287106.27 ( +0.00%) 95589.73 ( -66.71%)
File refaults 551697.60 ( +0.00%) 426474.80 ( -22.70%)
Link: https://lkml.kernel.org/r/20250416135142.778933-3-hannes@cmpxchg.org
Fixes:
|
||
|
Johannes Weiner
|
3844818145 |
mm: vmscan: restore high-cpu watermark safety in kswapd
Vlastimil points out that commit |
||
|
David Hildenbrand
|
8bdea2fce9 |
mm/memory: move sanity checks in do_wp_page() after mapcount vs. refcount stabilization
In __folio_remove_rmap() for RMAP_LEVEL_PMD/RMAP_LEVEL_PUD and with
CONFIG_PAGE_MAPCOUNT we first decrement the folio mapcount (and recompute
mapped shared vs. mapped exclusively) to then adjust the entire mapcount.
This means that another process might stumble in do_wp_page() over a
PTE-mapped PMD folio that is indicated as "exclusively mapped", but still
has an entire mapcount (PMD mapping), because it is racing with the
process that is unmapping the folio (PMD mapping). Note that do_wp_page()
will back off once it detects the remaining folio reference from the
process that is in the process of unmapping the folio.
This will trigger the early VM_WARN_ON_ONCE(folio_entire_mapcount(folio))
check in do_wp_page(), that can easily be reproduced by looping a couple
of times over allocating a PMD THP, forking a child where we immediately
unmap it again, and writing in the parent concurrently to the THP.
[ 252.738129][T16470] ------------[ cut here ]------------
[ 252.739267][T16470] WARNING: CPU: 3 PID: 16470 at mm/memory.c:3738 do_wp_page+0x2a75/0x2c00
[ 252.740968][T16470] Modules linked in:
[ 252.741958][T16470] CPU: 3 UID: 0 PID: 16470 Comm: ...
...
[ 252.765841][T16470] <TASK>
[ 252.766419][T16470] ? srso_alias_return_thunk+0x5/0xfbef5
[ 252.767558][T16470] ? rcu_is_watching+0x12/0x60
[ 252.768525][T16470] ? srso_alias_return_thunk+0x5/0xfbef5
[ 252.769645][T16470] ? srso_alias_return_thunk+0x5/0xfbef5
[ 252.770778][T16470] ? lock_acquire+0x33/0x80
[ 252.771697][T16470] ? __handle_mm_fault+0x5e8/0x3e40
[ 252.772735][T16470] ? __handle_mm_fault+0x5e8/0x3e40
[ 252.773781][T16470] __handle_mm_fault+0x1869/0x3e40
[ 252.774839][T16470] handle_mm_fault+0x22a/0x640
[ 252.775808][T16470] do_user_addr_fault+0x618/0x1000
[ 252.776847][T16470] exc_page_fault+0x68/0xd0
[ 252.777775][T16470] asm_exc_page_fault+0x26/0x30
While we could adjust the sequence in __folio_remove_rmap(), let's rater
move the mapcount sanity checks after the mapcount vs. refcount
stabilization phase. With this fix, a simple reproducer is happy.
While at it, convert the two VM_WARN_ON_ONCE() we are moving to
VM_WARN_ON_ONCE_FOLIO().
Link: https://lkml.kernel.org/r/20250415095007.569836-1-david@redhat.com
Fixes:
|
||
|
Oscar Salvador
|
274fe92de2 |
mm, hugetlb: increment the number of pages to be reset on HVO
commit |
||
|
Baoquan He
|
8c03ebd7cd |
mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable()
Not like fault_in_readable() or fault_in_writeable(), in
fault_in_safe_writeable() local variable 'start' is increased page by page
to loop till the whole address range is handled. However, it mistakenly
calculates the size of the handled range with 'uaddr - start'.
Fix it here.
Andreas said:
: In gfs2, fault_in_iov_iter_writeable() is used in
: gfs2_file_direct_read() and gfs2_file_read_iter(), so this potentially
: affects buffered as well as direct reads. This bug could cause those
: gfs2 functions to spin in a loop.
Link: https://lkml.kernel.org/r/20250410035717.473207-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20250410035717.473207-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Fixes:
|
||
|
Muchun Song
|
6b956934ad |
mm: memcontrol: fix swap counter leak from offline cgroup
commit |
||
|
Kirill A. Shutemov
|
4067196a52 |
mm/page_alloc: fix deadlock on cpu_hotplug_lock in __accept_page()
When the last page in the zone is accepted, __accept_page() calls
static_branch_dec(). This function takes cpu_hotplug_lock, which can lead
to a deadlock if the allocation occurs during CPU bringup path as
_cpu_up() also takes the lock.
To prevent this deadlock, defer static_branch_dec() to a workqueue.
Call static_branch_dec() only when the workqueue is not yet initialized.
Workqueues are initialized before CPU bring up, so this will not conflict
with the first scenario.
Link: https://lkml.kernel.org/r/20250329171030.3942298-1-kirill.shutemov@linux.intel.com
Fixes:
|
||
|
Linus Torvalds
|
a54f4a97e3 |
slab fix for 6.15-rc2
-----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEe7vIQRWZI0iWSE3xu+CwddJFiJoFAmgAyqUACgkQu+CwddJF iJrbtQf/Z4yPM96vm+AFPYrzZHvLKMgjpu7bb5M+6kHLjnu7eZ1n82rnGZ+kBFxp uUbDSGkh6U608P8Va6Fd6FBtwr9bFvCrL3Ek4XMDuuAbOUrZ3w9YvhDXeMxdUnLi KpVLT3BVc7kA3EP5gQsQm1zesAFlknwwXTKEBETS5zuferxYpatghQdqK/JbBoVp h7EJ8HThCLoy3UOm6nb/wmkNn1i6Vl+W9VY81fFOHmMLnt8ISNeRcjUu1EvlP1jy TAPHBisMd4nKpIedNARXFChQvm04zSjNgoDD6hHFFVu/alljDHxFMhLM7tjp/zjQ Cab2Vb7jTbdOmuV06+oF3wik2a58sg== =AYL8 -----END PGP SIGNATURE----- Merge tag 'slab-for-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fix from Vlastimil Babka: - Stable fix adding zero initialization of slab->obj_ext to prevent crashes with allocation profiling (Suren Baghdasaryan) * tag 'slab-for-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: slab: ensure slab->obj_exts is clear in a newly allocated slab page |
||
|
Vincenzo Frascino
|
62d32440ac |
kasan: Add strscpy() test to trigger tag fault on arm64
When we invoke strscpy() with a maximum size of N bytes, it assumes that: - It can always read N bytes from the source. - It always write N bytes (zero-padded) to the destination. On aarch64 with Memory Tagging Extension enabled if we pass an N that is bigger then the source buffer, it would previously trigger an MTE fault. Implement a KASAN KUnit test that triggers the issue with the previous implementation of read_word_at_a_time() on aarch64 with MTE enabled. Cc: Will Deacon <will@kernel.org> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Co-developed-by: Peter Collingbourne <pcc@google.com> Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://linux-review.googlesource.com/id/If88e396b9e7c058c1a4b5a252274120e77b1898a Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20250403000703.2584581-3-pcc@google.com Signed-off-by: Kees Cook <kees@kernel.org> |
||
|
Suren Baghdasaryan
|
d2f5819b6e |
slab: ensure slab->obj_exts is clear in a newly allocated slab page
ktest recently reported crashes while running several buffered io tests
with __alloc_tagging_slab_alloc_hook() at the top of the crash call stack.
The signature indicates an invalid address dereference with low bits of
slab->obj_exts being set. The bits were outside of the range used by
page_memcg_data_flags and objext_flags and hence were not masked out
by slab_obj_exts() when obtaining the pointer stored in slab->obj_exts.
The typical crash log looks like this:
00510 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
00510 Mem abort info:
00510 ESR = 0x0000000096000045
00510 EC = 0x25: DABT (current EL), IL = 32 bits
00510 SET = 0, FnV = 0
00510 EA = 0, S1PTW = 0
00510 FSC = 0x05: level 1 translation fault
00510 Data abort info:
00510 ISV = 0, ISS = 0x00000045, ISS2 = 0x00000000
00510 CM = 0, WnR = 1, TnD = 0, TagAccess = 0
00510 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
00510 user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104175000
00510 [0000000000000010] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
00510 Internal error: Oops: 0000000096000045 [#1] SMP
00510 Modules linked in:
00510 CPU: 10 UID: 0 PID: 7692 Comm: cat Not tainted 6.15.0-rc1-ktest-g189e17946605 #19327 NONE
00510 Hardware name: linux,dummy-virt (DT)
00510 pstate: 20001005 (nzCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
00510 pc : __alloc_tagging_slab_alloc_hook+0xe0/0x190
00510 lr : __kmalloc_noprof+0x150/0x310
00510 sp : ffffff80c87df6c0
00510 x29: ffffff80c87df6c0 x28: 000000000013d1ff x27: 000000000013d200
00510 x26: ffffff80c87df9e0 x25: 0000000000000000 x24: 0000000000000001
00510 x23: ffffffc08041953c x22: 000000000000004c x21: ffffff80c0002180
00510 x20: fffffffec3120840 x19: ffffff80c4821000 x18: 0000000000000000
00510 x17: fffffffec3d02f00 x16: fffffffec3d02e00 x15: fffffffec3d00700
00510 x14: fffffffec3d00600 x13: 0000000000000200 x12: 0000000000000006
00510 x11: ffffffc080bb86c0 x10: 0000000000000000 x9 : ffffffc080201e58
00510 x8 : ffffff80c4821060 x7 : 0000000000000000 x6 : 0000000055555556
00510 x5 : 0000000000000001 x4 : 0000000000000010 x3 : 0000000000000060
00510 x2 : 0000000000000000 x1 : ffffffc080f50cf8 x0 : ffffff80d801d000
00510 Call trace:
00510 __alloc_tagging_slab_alloc_hook+0xe0/0x190 (P)
00510 __kmalloc_noprof+0x150/0x310
00510 __bch2_folio_create+0x5c/0xf8
00510 bch2_folio_create+0x2c/0x40
00510 bch2_readahead+0xc0/0x460
00510 read_pages+0x7c/0x230
00510 page_cache_ra_order+0x244/0x3a8
00510 page_cache_async_ra+0x124/0x170
00510 filemap_readahead.isra.0+0x58/0xa0
00510 filemap_get_pages+0x454/0x7b0
00510 filemap_read+0xdc/0x418
00510 bch2_read_iter+0x100/0x1b0
00510 vfs_read+0x214/0x300
00510 ksys_read+0x6c/0x108
00510 __arm64_sys_read+0x20/0x30
00510 invoke_syscall.constprop.0+0x54/0xe8
00510 do_el0_svc+0x44/0xc8
00510 el0_svc+0x18/0x58
00510 el0t_64_sync_handler+0x104/0x130
00510 el0t_64_sync+0x154/0x158
00510 Code: d5384100 f9401c01 b9401aa3 b40002e1 (f8227881)
00510 ---[ end trace 0000000000000000 ]---
00510 Kernel panic - not syncing: Oops: Fatal exception
00510 SMP: stopping secondary CPUs
00510 Kernel Offset: disabled
00510 CPU features: 0x0000,000000e0,00000410,8240500b
00510 Memory Limit: none
Investigation indicates that these bits are already set when we allocate
slab page and are not zeroed out after allocation. We are not yet sure
why these crashes start happening only recently but regardless of the
reason, not initializing a field that gets used later is wrong. Fix it
by initializing slab->obj_exts during slab page allocation.
Fixes:
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Kirill A. Shutemov
|
a995199384 |
mm: fix apply_to_existing_page_range()
In the case of apply_to_existing_page_range(), apply_to_pte_range() is
reached with 'create' set to false. When !create, the loop over the PTE
page table is broken.
apply_to_pte_range() will only move to the next PTE entry if 'create' is
true or if the current entry is not pte_none().
This means that the user of apply_to_existing_page_range() will not have
'fn' called for any entries after the first pte_none() in the PTE page
table.
Fix the loop logic in apply_to_pte_range().
There are no known runtime issues from this, but the fix is trivial enough
for stable@ even without a known buggy user.
Link: https://lkml.kernel.org/r/20250409094043.1629234-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Fixes:
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|
David Hildenbrand
|
8c56c5dbcf |
mm: (un)track_pfn_copy() fix + doc improvements
We got a late smatch warning and some additional review feedback.
smatch warnings:
mm/memory.c:1428 copy_page_range() error: uninitialized symbol 'pfn'.
We actually use the pfn only when it is properly initialized; however, we
may pass an uninitialized value to a function -- although it will not use
it that likely still is UB in C.
So let's just fix it by always initializing pfn in the caller of
track_pfn_copy(), and improving the documentation of track_pfn_copy().
While at it, clarify the doc of untrack_pfn_copy(), that internal checks
make sure if we actually have to untrack anything.
Link: https://lkml.kernel.org/r/20250408085950.976103-1-david@redhat.com
Fixes:
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|
Vishal Moola (Oracle)
|
8ab1b16023 |
mm: fix filemap_get_folios_contig returning batches of identical folios
filemap_get_folios_contig() is supposed to return distinct folios found
within [start, end]. Large folios in the Xarray become multi-index
entries. xas_next() can iterate through the sub-indexes before finding a
sibling entry and breaking out of the loop.
This can result in a returned folio_batch containing an indeterminate
number of duplicate folios, which forces the callers to skeptically handle
the returned batch. This is inefficient and incurs a large maintenance
overhead.
We can fix this by calling xas_advance() after we have successfully adding
a folio to the batch to ensure our Xarray is positioned such that it will
correctly find the next folio - similar to filemap_get_read_batch().
Link: https://lkml.kernel.org/r/Z-8s1-kiIDkzgRbc@fedora
Fixes:
|
||
|
wangxuewen
|
9e2bd67773 |
mm/hugetlb: add a line break at the end of the format string
Missing line break at the end of the format string. Link: https://lkml.kernel.org/r/20250407103017.2979821-1-18810879172@163.com Signed-off-by: wangxuewen <wangxuewen@kylinos.cn> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |