CVE-2024-42266 (GCVE-0-2024-42266)
Vulnerability from cvelistv5 – Published: 2024-08-17 08:54 – Updated: 2026-08-05 11:36
VLAI
EPSS
VEX
Title
btrfs: make cow_file_range_inline() honor locked_page on error
Summary
In the Linux kernel, the following vulnerability has been resolved:
btrfs: make cow_file_range_inline() honor locked_page on error
The btrfs buffered write path runs through __extent_writepage() which
has some tricky return value handling for writepage_delalloc().
Specifically, when that returns 1, we exit, but for other return values
we continue and end up calling btrfs_folio_end_all_writers(). If the
folio has been unlocked (note that we check the PageLocked bit at the
start of __extent_writepage()), this results in an assert panic like
this one from syzbot:
BTRFS: error (device loop0 state EAL) in free_log_tree:3267: errno=-5 IO failure
BTRFS warning (device loop0 state EAL): Skipping commit of aborted transaction.
BTRFS: error (device loop0 state EAL) in cleanup_transaction:2018: errno=-5 IO failure
assertion failed: folio_test_locked(folio), in fs/btrfs/subpage.c:871
------------[ cut here ]------------
kernel BUG at fs/btrfs/subpage.c:871!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 PID: 5090 Comm: syz-executor225 Not tainted
6.10.0-syzkaller-05505-gb1bc554e009e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 06/27/2024
RIP: 0010:btrfs_folio_end_all_writers+0x55b/0x610 fs/btrfs/subpage.c:871
Code: e9 d3 fb ff ff e8 25 22 c2 fd 48 c7 c7 c0 3c 0e 8c 48 c7 c6 80 3d
0e 8c 48 c7 c2 60 3c 0e 8c b9 67 03 00 00 e8 66 47 ad 07 90 <0f> 0b e8
6e 45 b0 07 4c 89 ff be 08 00 00 00 e8 21 12 25 fe 4c 89
RSP: 0018:ffffc900033d72e0 EFLAGS: 00010246
RAX: 0000000000000045 RBX: 00fff0000000402c RCX: 663b7a08c50a0a00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900033d73b0 R08: ffffffff8176b98c R09: 1ffff9200067adfc
R10: dffffc0000000000 R11: fffff5200067adfd R12: 0000000000000001
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffea0001cbee80
FS: 0000000000000000(0000) GS:ffff8880b9500000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5f076012f8 CR3: 000000000e134000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__extent_writepage fs/btrfs/extent_io.c:1597 [inline]
extent_write_cache_pages fs/btrfs/extent_io.c:2251 [inline]
btrfs_writepages+0x14d7/0x2760 fs/btrfs/extent_io.c:2373
do_writepages+0x359/0x870 mm/page-writeback.c:2656
filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397
__filemap_fdatawrite_range mm/filemap.c:430 [inline]
__filemap_fdatawrite mm/filemap.c:436 [inline]
filemap_flush+0xdf/0x130 mm/filemap.c:463
btrfs_release_file+0x117/0x130 fs/btrfs/file.c:1547
__fput+0x24a/0x8a0 fs/file_table.c:422
task_work_run+0x24f/0x310 kernel/task_work.c:222
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0xa2f/0x27f0 kernel/exit.c:877
do_group_exit+0x207/0x2c0 kernel/exit.c:1026
__do_sys_exit_group kernel/exit.c:1037 [inline]
__se_sys_exit_group kernel/exit.c:1035 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035
x64_sys_call+0x2634/0x2640
arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f075b70c9
Code: Unable to access opcode bytes at
0x7f5f075b709f.
I was hitting the same issue by doing hundreds of accelerated runs of
generic/475, which also hits IO errors by design.
I instrumented that reproducer with bpftrace and found that the
undesirable folio_unlock was coming from the following callstack:
folio_unlock+5
__process_pages_contig+475
cow_file_range_inline.constprop.0+230
cow_file_range+803
btrfs_run_delalloc_range+566
writepage_delalloc+332
__extent_writepage # inlined in my stacktrace, but I added it here
extent_write_cache_pages+622
Looking at the bisected-to pa
---truncated---
Severity
7.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-09-10 16:12 UTC
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
0586d0a89e77d717da14df42648ace4a9fd67981 , < 061e41581606000a83ce0f0f01d6ad338f3704e9
(git)
Affected: 0586d0a89e77d717da14df42648ace4a9fd67981 , < 478574370bef7951fbd9ef5155537d6cbed49472 (git) |
guessed | |
| Linux | Linux |
Affected:
6.10
Unaffected: 0 , < 6.10 (semver) Unaffected: 6.10.4 , ≤ 6.10.* (semver) Unaffected: 6.11 , ≤ * (original_commit_for_fix) |
guessed |
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"id": "CVE-2024-42266",
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"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: make cow_file_range_inline() honor locked_page on error\n\nThe btrfs buffered write path runs through __extent_writepage() which\nhas some tricky return value handling for writepage_delalloc().\nSpecifically, when that returns 1, we exit, but for other return values\nwe continue and end up calling btrfs_folio_end_all_writers(). If the\nfolio has been unlocked (note that we check the PageLocked bit at the\nstart of __extent_writepage()), this results in an assert panic like\nthis one from syzbot:\n\n BTRFS: error (device loop0 state EAL) in free_log_tree:3267: errno=-5 IO failure\n BTRFS warning (device loop0 state EAL): Skipping commit of aborted transaction.\n BTRFS: error (device loop0 state EAL) in cleanup_transaction:2018: errno=-5 IO failure\n assertion failed: folio_test_locked(folio), in fs/btrfs/subpage.c:871\n ------------[ cut here ]------------\n kernel BUG at fs/btrfs/subpage.c:871!\n Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI\n CPU: 1 PID: 5090 Comm: syz-executor225 Not tainted\n 6.10.0-syzkaller-05505-gb1bc554e009e #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS\n Google 06/27/2024\n RIP: 0010:btrfs_folio_end_all_writers+0x55b/0x610 fs/btrfs/subpage.c:871\n Code: e9 d3 fb ff ff e8 25 22 c2 fd 48 c7 c7 c0 3c 0e 8c 48 c7 c6 80 3d\n 0e 8c 48 c7 c2 60 3c 0e 8c b9 67 03 00 00 e8 66 47 ad 07 90 \u003c0f\u003e 0b e8\n 6e 45 b0 07 4c 89 ff be 08 00 00 00 e8 21 12 25 fe 4c 89\n RSP: 0018:ffffc900033d72e0 EFLAGS: 00010246\n RAX: 0000000000000045 RBX: 00fff0000000402c RCX: 663b7a08c50a0a00\n RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000\n RBP: ffffc900033d73b0 R08: ffffffff8176b98c R09: 1ffff9200067adfc\n R10: dffffc0000000000 R11: fffff5200067adfd R12: 0000000000000001\n R13: dffffc0000000000 R14: 0000000000000000 R15: ffffea0001cbee80\n FS: 0000000000000000(0000) GS:ffff8880b9500000(0000)\n knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f5f076012f8 CR3: 000000000e134000 CR4: 00000000003506f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n \u003cTASK\u003e\n __extent_writepage fs/btrfs/extent_io.c:1597 [inline]\n extent_write_cache_pages fs/btrfs/extent_io.c:2251 [inline]\n btrfs_writepages+0x14d7/0x2760 fs/btrfs/extent_io.c:2373\n do_writepages+0x359/0x870 mm/page-writeback.c:2656\n filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397\n __filemap_fdatawrite_range mm/filemap.c:430 [inline]\n __filemap_fdatawrite mm/filemap.c:436 [inline]\n filemap_flush+0xdf/0x130 mm/filemap.c:463\n btrfs_release_file+0x117/0x130 fs/btrfs/file.c:1547\n __fput+0x24a/0x8a0 fs/file_table.c:422\n task_work_run+0x24f/0x310 kernel/task_work.c:222\n exit_task_work include/linux/task_work.h:40 [inline]\n do_exit+0xa2f/0x27f0 kernel/exit.c:877\n do_group_exit+0x207/0x2c0 kernel/exit.c:1026\n __do_sys_exit_group kernel/exit.c:1037 [inline]\n __se_sys_exit_group kernel/exit.c:1035 [inline]\n __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035\n x64_sys_call+0x2634/0x2640\n arch/x86/include/generated/asm/syscalls_64.h:232\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7f5f075b70c9\n Code: Unable to access opcode bytes at\n 0x7f5f075b709f.\n\nI was hitting the same issue by doing hundreds of accelerated runs of\ngeneric/475, which also hits IO errors by design.\n\nI instrumented that reproducer with bpftrace and found that the\nundesirable folio_unlock was coming from the following callstack:\n\n folio_unlock+5\n __process_pages_contig+475\n cow_file_range_inline.constprop.0+230\n cow_file_range+803\n btrfs_run_delalloc_range+566\n writepage_delalloc+332\n __extent_writepage # inlined in my stacktrace, but I added it here\n extent_write_cache_pages+622\n\nLooking at the bisected-to pa\n---truncated---"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The vulnerable code is the btrfs buffered-write/writeback path, reached through ordinary local syscalls (write/close/fsync) on a mounted btrfs filesystem. No network protocol handling is involved, so local access to the machine is required.\nAC:L - The attacker fully controls the trigger \u2014 create a small (\u003c=2048 byte) file at offset 0 so the inline-extent path is taken, and drive cow_file_range_inline() to a negative return via attacker-inducible memory pressure (-ENOMEM in btrfs_alloc_path/btrfs_join_transaction) or on an already-aborted/EROFS filesystem where the failure is deterministic; the write/close loop can be repeated indefinitely until it fires.\nPR:L - Any unprivileged local user with write access to any btrfs filesystem (e.g. /home or /tmp) can reach the path; no capabilities, mount privileges, or user-namespace tricks are needed.\nUI:N - The attacker\u0027s own write and close trigger writeback via btrfs_release_file()-\u003efilemap_flush(), exactly as in the syzbot stack trace; no victim action is required.\nS:U - The corrupted state (folio lock bits, btrfs page-cache pages) and the resulting panic or hang are confined to the kernel of the same host, with no crossing of a VM, IOMMU, or other security authority boundary.\nC:H - The double unlock destroys page-lock mutual exclusion on a page-cache folio, letting a second thread operate on a folio concurrently with truncate/invalidate/reclaim and read data from a folio that can be freed and reused underneath it, a use-after-free style read primitive over page cache contents.\nI:H - With the page lock invariant broken, two threads can simultaneously believe they own a folio that is being started into writeback, allowing writes into a folio racing removal from the mapping and reuse, i.e. memory corruption leveragable beyond a mere crash.\nA:H - On kernels with CONFIG_BTRFS_ASSERT this is an immediate kernel BUG/panic at fs/btrfs/subpage.c:871; otherwise folio_unlock()\u0027s xor re-sets PG_locked on an ownerless folio, wedging every future access to that page in an unkillable D-state and blocking inode eviction and unmount."
}
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"dateUpdated": "2026-08-05T11:36:11.043Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"references": [
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{
"url": "https://git.kernel.org/stable/c/478574370bef7951fbd9ef5155537d6cbed49472"
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"title": "btrfs: make cow_file_range_inline() honor locked_page on error",
"x_generator": {
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"cveMetadata": {
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"cveId": "CVE-2024-42266",
"datePublished": "2024-08-17T08:54:22.308Z",
"dateReserved": "2024-07-30T07:40:12.259Z",
"dateUpdated": "2026-08-05T11:36:11.043Z",
"state": "PUBLISHED"
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"epss": {
"cve": "CVE-2024-42266",
"date": "2026-09-25",
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"percentile": "0.0915"
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"fkie_nvd": {
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: make cow_file_range_inline() honor locked_page on error\n\nThe btrfs buffered write path runs through __extent_writepage() which\nhas some tricky return value handling for writepage_delalloc().\nSpecifically, when that returns 1, we exit, but for other return values\nwe continue and end up calling btrfs_folio_end_all_writers(). If the\nfolio has been unlocked (note that we check the PageLocked bit at the\nstart of __extent_writepage()), this results in an assert panic like\nthis one from syzbot:\n\n BTRFS: error (device loop0 state EAL) in free_log_tree:3267: errno=-5 IO failure\n BTRFS warning (device loop0 state EAL): Skipping commit of aborted transaction.\n BTRFS: error (device loop0 state EAL) in cleanup_transaction:2018: errno=-5 IO failure\n assertion failed: folio_test_locked(folio), in fs/btrfs/subpage.c:871\n ------------[ cut here ]------------\n kernel BUG at fs/btrfs/subpage.c:871!\n Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI\n CPU: 1 PID: 5090 Comm: syz-executor225 Not tainted\n 6.10.0-syzkaller-05505-gb1bc554e009e #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS\n Google 06/27/2024\n RIP: 0010:btrfs_folio_end_all_writers+0x55b/0x610 fs/btrfs/subpage.c:871\n Code: e9 d3 fb ff ff e8 25 22 c2 fd 48 c7 c7 c0 3c 0e 8c 48 c7 c6 80 3d\n 0e 8c 48 c7 c2 60 3c 0e 8c b9 67 03 00 00 e8 66 47 ad 07 90 \u003c0f\u003e 0b e8\n 6e 45 b0 07 4c 89 ff be 08 00 00 00 e8 21 12 25 fe 4c 89\n RSP: 0018:ffffc900033d72e0 EFLAGS: 00010246\n RAX: 0000000000000045 RBX: 00fff0000000402c RCX: 663b7a08c50a0a00\n RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000\n RBP: ffffc900033d73b0 R08: ffffffff8176b98c R09: 1ffff9200067adfc\n R10: dffffc0000000000 R11: fffff5200067adfd R12: 0000000000000001\n R13: dffffc0000000000 R14: 0000000000000000 R15: ffffea0001cbee80\n FS: 0000000000000000(0000) GS:ffff8880b9500000(0000)\n knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f5f076012f8 CR3: 000000000e134000 CR4: 00000000003506f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n \u003cTASK\u003e\n __extent_writepage fs/btrfs/extent_io.c:1597 [inline]\n extent_write_cache_pages fs/btrfs/extent_io.c:2251 [inline]\n btrfs_writepages+0x14d7/0x2760 fs/btrfs/extent_io.c:2373\n do_writepages+0x359/0x870 mm/page-writeback.c:2656\n filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397\n __filemap_fdatawrite_range mm/filemap.c:430 [inline]\n __filemap_fdatawrite mm/filemap.c:436 [inline]\n filemap_flush+0xdf/0x130 mm/filemap.c:463\n btrfs_release_file+0x117/0x130 fs/btrfs/file.c:1547\n __fput+0x24a/0x8a0 fs/file_table.c:422\n task_work_run+0x24f/0x310 kernel/task_work.c:222\n exit_task_work include/linux/task_work.h:40 [inline]\n do_exit+0xa2f/0x27f0 kernel/exit.c:877\n do_group_exit+0x207/0x2c0 kernel/exit.c:1026\n __do_sys_exit_group kernel/exit.c:1037 [inline]\n __se_sys_exit_group kernel/exit.c:1035 [inline]\n __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035\n x64_sys_call+0x2634/0x2640\n arch/x86/include/generated/asm/syscalls_64.h:232\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7f5f075b70c9\n Code: Unable to access opcode bytes at\n 0x7f5f075b709f.\n\nI was hitting the same issue by doing hundreds of accelerated runs of\ngeneric/475, which also hits IO errors by design.\n\nI instrumented that reproducer with bpftrace and found that the\nundesirable folio_unlock was coming from the following callstack:\n\n folio_unlock+5\n __process_pages_contig+475\n cow_file_range_inline.constprop.0+230\n cow_file_range+803\n btrfs_run_delalloc_range+566\n writepage_delalloc+332\n __extent_writepage # inlined in my stacktrace, but I added it here\n extent_write_cache_pages+622\n\nLooking at the bisected-to pa\n---truncated---"
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: haga que cow_file_range_inline() respete la p\u00e1gina bloqueada en caso de error. La ruta de escritura almacenada en el b\u00fafer de btrfs pasa por __extent_writepage(), que tiene un manejo complicado del valor de retorno para writepage_delalloc(). Espec\u00edficamente, cuando eso devuelve 1, salimos, pero para otros valores de retorno continuamos y terminamos llamando a btrfs_folio_end_all_writers(). Si la publicaci\u00f3n se ha desbloqueado (tenga en cuenta que verificamos el bit PageLocked al inicio de __extent_writepage()), esto resulta en un p\u00e1nico de afirmaci\u00f3n como este de syzbot: BTRFS: error (device loop0 state EAL) in free_log_tree:3267: errno = -5 Fallo de E/S Advertencia BTRFS (estado EAL del bucle 0 del dispositivo): omitir El commit de la transacci\u00f3n abortada. BTRFS: error (EAL de estado de bucle 0 del dispositivo) en cleanup_transaction:2018: errno=-5 Error de aserci\u00f3n de E/S fallida: folio_test_locked(folio), en fs/btrfs/subpage.c:871 ------------ [cortar aqu\u00ed]------------ \u00a1ERROR del kernel en fs/btrfs/subpage.c:871! Vaya: c\u00f3digo de operaci\u00f3n no v\u00e1lido: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 PID: 5090 Comm: syz-executor225 No est\u00e1 contaminado 6.10.0-syzkaller-05505-gb1bc554e009e #0 Nombre de hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 27/06/2024 RIP: 0010:btrfs_folio_end_all_writers+0x55b/0x610 fs/btrfs/subpage.c:871 C\u00f3digo: e9 d3 fb ff ff e8 25 22 c2 fd 48 c7 c7 c0 3c 0e 8c 48 c7 c6 80 3d 0e 8c 48 c7 c2 60 3c 0e 8c b9 67 03 00 00 e8 66 47 ad 07 90 \u0026lt;0f\u0026gt; 0b e8 6e 45 b0 07 4c 89 ff be 08 00 00 00 e8 21 12 25 fe 4c 89 RSP: 00033d72e0 EFLAGS: 00010246 RAX: 0000000000000045 RBX: 00fff0000000402c RCX: 663b7a08c50a0a00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 000000000 0000000 RBP: ffffc900033d73b0 R08: ffffffff8176b98c R09: 1ffff9200067adfc R10: dffffc0000000000 R11: fffff5200067adfd R12: 0000000000000001 R13: 0000000000 R14: 0000000000000000 R15: ffffea0001cbee80 FS: 0000000000000000( 0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5f076012f8 CR3: e134000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffe0ff0 DR7: 0000000000000400 Seguimiento de llamadas: __extent_writepage fs/btrfs/extent_io.c:1597 [en l\u00ednea] extend_write_cache_pages fs/btrfs/extent_io.c:2251 [en l\u00ednea] btrfs_writepages+0x14d7/0x2760 fs/btrfs/extent_io.c:2373 do_writepages+0x359/ 0x870 mm/page-writeback.c:2656 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397 __filemap_fdatawrite_range mm/filemap.c:430 [en l\u00ednea] __filemap_fdatawrite mm/filemap.c:436 [en l\u00ednea] filemap_flush+0xdf/0x130 mm /filemap.c:463 btrfs_release_file+0x117/0x130 fs/btrfs/file.c:1547 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:222 exit_task_work include/linux/task_work .h:40 [en l\u00ednea] do_exit+0xa2f/0x27f0 kernel/exit.c:877 do_group_exit+0x207/0x2c0 kernel/exit.c:1026 __do_sys_exit_group kernel/exit.c:1037 [en l\u00ednea] __se_sys_exit_group kernel/exit.c:1035 [en l\u00ednea] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [en l\u00ednea] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5f075b70c9 C\u00f3digo: No se puede acceder a los bytes del c\u00f3digo de operaci\u00f3n en 0x7f5f075b709f. Me encontr\u00e9 con el mismo problema al realizar cientos de ejecuciones aceleradas de generic/475, que tambi\u00e9n genera errores de IO por dise\u00f1o. Instrument\u00e9 ese reproductor con bpftrace y descubr\u00ed que el folio_unlock no deseado proven\u00eda de la siguiente pila de llamadas: folio_unlock+5 __process_pages_contig+475 cow_file_range_inline.constprop.0+230 cow_file_range+803 btrfs_run_delalloc_range+566 writepage_delalloc+332 __extent_writepage # ---truncado---"
}
],
"id": "CVE-2024-42266",
"lastModified": "2024-08-19T12:59:59.177",
"published": "2024-08-17T09:15:07.967",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/061e41581606000a83ce0f0f01d6ad338f3704e9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/478574370bef7951fbd9ef5155537d6cbed49472"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/btrfs/inode.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "061e41581606000a83ce0f0f01d6ad338f3704e9",
"status": "affected",
"version": "0586d0a89e77d717da14df42648ace4a9fd67981",
"versionType": "git"
},
{
"lessThan": "478574370bef7951fbd9ef5155537d6cbed49472",
"status": "affected",
"version": "0586d0a89e77d717da14df42648ace4a9fd67981",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/btrfs/inode.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.10"
},
{
"lessThan": "6.10",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.10.*",
"status": "unaffected",
"version": "6.10.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.11",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "58294AC2-8D9E-4C90-B6EC-7C210C28ECB6",
"versionEndExcluding": "6.10.4",
"versionStartIncluding": "6.10",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*",
"matchCriteriaId": "8B3CE743-2126-47A3-8B7C-822B502CF119",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: make cow_file_range_inline() honor locked_page on error\n\nThe btrfs buffered write path runs through __extent_writepage() which\nhas some tricky return value handling for writepage_delalloc().\nSpecifically, when that returns 1, we exit, but for other return values\nwe continue and end up calling btrfs_folio_end_all_writers(). If the\nfolio has been unlocked (note that we check the PageLocked bit at the\nstart of __extent_writepage()), this results in an assert panic like\nthis one from syzbot:\n\n BTRFS: error (device loop0 state EAL) in free_log_tree:3267: errno=-5 IO failure\n BTRFS warning (device loop0 state EAL): Skipping commit of aborted transaction.\n BTRFS: error (device loop0 state EAL) in cleanup_transaction:2018: errno=-5 IO failure\n assertion failed: folio_test_locked(folio), in fs/btrfs/subpage.c:871\n ------------[ cut here ]------------\n kernel BUG at fs/btrfs/subpage.c:871!\n Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI\n CPU: 1 PID: 5090 Comm: syz-executor225 Not tainted\n 6.10.0-syzkaller-05505-gb1bc554e009e #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS\n Google 06/27/2024\n RIP: 0010:btrfs_folio_end_all_writers+0x55b/0x610 fs/btrfs/subpage.c:871\n Code: e9 d3 fb ff ff e8 25 22 c2 fd 48 c7 c7 c0 3c 0e 8c 48 c7 c6 80 3d\n 0e 8c 48 c7 c2 60 3c 0e 8c b9 67 03 00 00 e8 66 47 ad 07 90 \u003c0f\u003e 0b e8\n 6e 45 b0 07 4c 89 ff be 08 00 00 00 e8 21 12 25 fe 4c 89\n RSP: 0018:ffffc900033d72e0 EFLAGS: 00010246\n RAX: 0000000000000045 RBX: 00fff0000000402c RCX: 663b7a08c50a0a00\n RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000\n RBP: ffffc900033d73b0 R08: ffffffff8176b98c R09: 1ffff9200067adfc\n R10: dffffc0000000000 R11: fffff5200067adfd R12: 0000000000000001\n R13: dffffc0000000000 R14: 0000000000000000 R15: ffffea0001cbee80\n FS: 0000000000000000(0000) GS:ffff8880b9500000(0000)\n knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f5f076012f8 CR3: 000000000e134000 CR4: 00000000003506f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n \u003cTASK\u003e\n __extent_writepage fs/btrfs/extent_io.c:1597 [inline]\n extent_write_cache_pages fs/btrfs/extent_io.c:2251 [inline]\n btrfs_writepages+0x14d7/0x2760 fs/btrfs/extent_io.c:2373\n do_writepages+0x359/0x870 mm/page-writeback.c:2656\n filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397\n __filemap_fdatawrite_range mm/filemap.c:430 [inline]\n __filemap_fdatawrite mm/filemap.c:436 [inline]\n filemap_flush+0xdf/0x130 mm/filemap.c:463\n btrfs_release_file+0x117/0x130 fs/btrfs/file.c:1547\n __fput+0x24a/0x8a0 fs/file_table.c:422\n task_work_run+0x24f/0x310 kernel/task_work.c:222\n exit_task_work include/linux/task_work.h:40 [inline]\n do_exit+0xa2f/0x27f0 kernel/exit.c:877\n do_group_exit+0x207/0x2c0 kernel/exit.c:1026\n __do_sys_exit_group kernel/exit.c:1037 [inline]\n __se_sys_exit_group kernel/exit.c:1035 [inline]\n __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035\n x64_sys_call+0x2634/0x2640\n arch/x86/include/generated/asm/syscalls_64.h:232\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7f5f075b70c9\n Code: Unable to access opcode bytes at\n 0x7f5f075b709f.\n\nI was hitting the same issue by doing hundreds of accelerated runs of\ngeneric/475, which also hits IO errors by design.\n\nI instrumented that reproducer with bpftrace and found that the\nundesirable folio_unlock was coming from the following callstack:\n\n folio_unlock+5\n __process_pages_contig+475\n cow_file_range_inline.constprop.0+230\n cow_file_range+803\n btrfs_run_delalloc_range+566\n writepage_delalloc+332\n __extent_writepage # inlined in my stacktrace, but I added it here\n extent_write_cache_pages+622\n\nLooking at the bisected-to pa\n---truncated---"
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: haga que cow_file_range_inline() respete la p\u00e1gina bloqueada en caso de error. La ruta de escritura almacenada en el b\u00fafer de btrfs pasa por __extent_writepage(), que tiene un manejo complicado del valor de retorno para writepage_delalloc(). Espec\u00edficamente, cuando eso devuelve 1, salimos, pero para otros valores de retorno continuamos y terminamos llamando a btrfs_folio_end_all_writers(). Si la publicaci\u00f3n se ha desbloqueado (tenga en cuenta que verificamos el bit PageLocked al inicio de __extent_writepage()), esto resulta en un p\u00e1nico de afirmaci\u00f3n como este de syzbot: BTRFS: error (device loop0 state EAL) in free_log_tree:3267: errno = -5 Fallo de E/S Advertencia BTRFS (estado EAL del bucle 0 del dispositivo): omitir El commit de la transacci\u00f3n abortada. BTRFS: error (EAL de estado de bucle 0 del dispositivo) en cleanup_transaction:2018: errno=-5 Error de aserci\u00f3n de E/S fallida: folio_test_locked(folio), en fs/btrfs/subpage.c:871 ------------ [cortar aqu\u00ed]------------ \u00a1ERROR del kernel en fs/btrfs/subpage.c:871! Vaya: c\u00f3digo de operaci\u00f3n no v\u00e1lido: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 PID: 5090 Comm: syz-executor225 No est\u00e1 contaminado 6.10.0-syzkaller-05505-gb1bc554e009e #0 Nombre de hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 27/06/2024 RIP: 0010:btrfs_folio_end_all_writers+0x55b/0x610 fs/btrfs/subpage.c:871 C\u00f3digo: e9 d3 fb ff ff e8 25 22 c2 fd 48 c7 c7 c0 3c 0e 8c 48 c7 c6 80 3d 0e 8c 48 c7 c2 60 3c 0e 8c b9 67 03 00 00 e8 66 47 ad 07 90 \u0026lt;0f\u0026gt; 0b e8 6e 45 b0 07 4c 89 ff be 08 00 00 00 e8 21 12 25 fe 4c 89 RSP: 00033d72e0 EFLAGS: 00010246 RAX: 0000000000000045 RBX: 00fff0000000402c RCX: 663b7a08c50a0a00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 000000000 0000000 RBP: ffffc900033d73b0 R08: ffffffff8176b98c R09: 1ffff9200067adfc R10: dffffc0000000000 R11: fffff5200067adfd R12: 0000000000000001 R13: 0000000000 R14: 0000000000000000 R15: ffffea0001cbee80 FS: 0000000000000000( 0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5f076012f8 CR3: e134000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffe0ff0 DR7: 0000000000000400 Seguimiento de llamadas: __extent_writepage fs/btrfs/extent_io.c:1597 [en l\u00ednea] extend_write_cache_pages fs/btrfs/extent_io.c:2251 [en l\u00ednea] btrfs_writepages+0x14d7/0x2760 fs/btrfs/extent_io.c:2373 do_writepages+0x359/ 0x870 mm/page-writeback.c:2656 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397 __filemap_fdatawrite_range mm/filemap.c:430 [en l\u00ednea] __filemap_fdatawrite mm/filemap.c:436 [en l\u00ednea] filemap_flush+0xdf/0x130 mm /filemap.c:463 btrfs_release_file+0x117/0x130 fs/btrfs/file.c:1547 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:222 exit_task_work include/linux/task_work .h:40 [en l\u00ednea] do_exit+0xa2f/0x27f0 kernel/exit.c:877 do_group_exit+0x207/0x2c0 kernel/exit.c:1026 __do_sys_exit_group kernel/exit.c:1037 [en l\u00ednea] __se_sys_exit_group kernel/exit.c:1035 [en l\u00ednea] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [en l\u00ednea] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5f075b70c9 C\u00f3digo: No se puede acceder a los bytes del c\u00f3digo de operaci\u00f3n en 0x7f5f075b709f. Me encontr\u00e9 con el mismo problema al realizar cientos de ejecuciones aceleradas de generic/475, que tambi\u00e9n genera errores de IO por dise\u00f1o. Instrument\u00e9 ese reproductor con bpftrace y descubr\u00ed que el folio_unlock no deseado proven\u00eda de la siguiente pila de llamadas: folio_unlock+5 __process_pages_contig+475 cow_file_range_inline.constprop.0+230 cow_file_range+803 btrfs_run_delalloc_range+566 writepage_delalloc+332 __extent_writepage # ---truncado---"
}
],
"id": "CVE-2024-42266",
"lastModified": "2026-08-04T11:19:43.813",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
},
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
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"options": [
{
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},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2024-09-10T16:12:27.580534Z",
"version": "2.0.3"
}
}
]
},
"published": "2024-08-17T09:15:07.967",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/061e41581606000a83ce0f0f01d6ad338f3704e9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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],
"url": "https://git.kernel.org/stable/c/478574370bef7951fbd9ef5155537d6cbed49472"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-476"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-08-04T18:28:37+00:00",
"cve": "CVE-2024-42266",
"id": "CVE-2024-42266",
"initial_release_date": "2024-08-17T00:00:00+00:00",
"product_status:known_affected": "42",
"product_status:known_not_affected": "156",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: btrfs: make cow_file_range_inline() honor locked_page on error",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2024/cve-2024-42266.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "moderate",
"current_release_date": "2026-09-03T00:22:29Z",
"cve": "CVE-2024-42266",
"id": "CVE-2024-42266",
"initial_release_date": "2024-08-18T02:02:55Z",
"product_status:known_not_affected": "371",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2024-42266",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2024-42266.json",
"version": "20"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2024-42266",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2024-09-10T16:12:27.580534Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2024-09-11T12:42:14.401Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/btrfs/inode.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "061e41581606000a83ce0f0f01d6ad338f3704e9",
"status": "affected",
"version": "0586d0a89e77d717da14df42648ace4a9fd67981",
"versionType": "git"
},
{
"lessThan": "478574370bef7951fbd9ef5155537d6cbed49472",
"status": "affected",
"version": "0586d0a89e77d717da14df42648ace4a9fd67981",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/btrfs/inode.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.10"
},
{
"lessThan": "6.10",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.10.*",
"status": "unaffected",
"version": "6.10.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.11",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.10.4",
"versionStartIncluding": "6.10",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.11",
"versionStartIncluding": "6.10",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: make cow_file_range_inline() honor locked_page on error\n\nThe btrfs buffered write path runs through __extent_writepage() which\nhas some tricky return value handling for writepage_delalloc().\nSpecifically, when that returns 1, we exit, but for other return values\nwe continue and end up calling btrfs_folio_end_all_writers(). If the\nfolio has been unlocked (note that we check the PageLocked bit at the\nstart of __extent_writepage()), this results in an assert panic like\nthis one from syzbot:\n\n BTRFS: error (device loop0 state EAL) in free_log_tree:3267: errno=-5 IO failure\n BTRFS warning (device loop0 state EAL): Skipping commit of aborted transaction.\n BTRFS: error (device loop0 state EAL) in cleanup_transaction:2018: errno=-5 IO failure\n assertion failed: folio_test_locked(folio), in fs/btrfs/subpage.c:871\n ------------[ cut here ]------------\n kernel BUG at fs/btrfs/subpage.c:871!\n Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI\n CPU: 1 PID: 5090 Comm: syz-executor225 Not tainted\n 6.10.0-syzkaller-05505-gb1bc554e009e #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS\n Google 06/27/2024\n RIP: 0010:btrfs_folio_end_all_writers+0x55b/0x610 fs/btrfs/subpage.c:871\n Code: e9 d3 fb ff ff e8 25 22 c2 fd 48 c7 c7 c0 3c 0e 8c 48 c7 c6 80 3d\n 0e 8c 48 c7 c2 60 3c 0e 8c b9 67 03 00 00 e8 66 47 ad 07 90 \u003c0f\u003e 0b e8\n 6e 45 b0 07 4c 89 ff be 08 00 00 00 e8 21 12 25 fe 4c 89\n RSP: 0018:ffffc900033d72e0 EFLAGS: 00010246\n RAX: 0000000000000045 RBX: 00fff0000000402c RCX: 663b7a08c50a0a00\n RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000\n RBP: ffffc900033d73b0 R08: ffffffff8176b98c R09: 1ffff9200067adfc\n R10: dffffc0000000000 R11: fffff5200067adfd R12: 0000000000000001\n R13: dffffc0000000000 R14: 0000000000000000 R15: ffffea0001cbee80\n FS: 0000000000000000(0000) GS:ffff8880b9500000(0000)\n knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f5f076012f8 CR3: 000000000e134000 CR4: 00000000003506f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n \u003cTASK\u003e\n __extent_writepage fs/btrfs/extent_io.c:1597 [inline]\n extent_write_cache_pages fs/btrfs/extent_io.c:2251 [inline]\n btrfs_writepages+0x14d7/0x2760 fs/btrfs/extent_io.c:2373\n do_writepages+0x359/0x870 mm/page-writeback.c:2656\n filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397\n __filemap_fdatawrite_range mm/filemap.c:430 [inline]\n __filemap_fdatawrite mm/filemap.c:436 [inline]\n filemap_flush+0xdf/0x130 mm/filemap.c:463\n btrfs_release_file+0x117/0x130 fs/btrfs/file.c:1547\n __fput+0x24a/0x8a0 fs/file_table.c:422\n task_work_run+0x24f/0x310 kernel/task_work.c:222\n exit_task_work include/linux/task_work.h:40 [inline]\n do_exit+0xa2f/0x27f0 kernel/exit.c:877\n do_group_exit+0x207/0x2c0 kernel/exit.c:1026\n __do_sys_exit_group kernel/exit.c:1037 [inline]\n __se_sys_exit_group kernel/exit.c:1035 [inline]\n __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035\n x64_sys_call+0x2634/0x2640\n arch/x86/include/generated/asm/syscalls_64.h:232\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7f5f075b70c9\n Code: Unable to access opcode bytes at\n 0x7f5f075b709f.\n\nI was hitting the same issue by doing hundreds of accelerated runs of\ngeneric/475, which also hits IO errors by design.\n\nI instrumented that reproducer with bpftrace and found that the\nundesirable folio_unlock was coming from the following callstack:\n\n folio_unlock+5\n __process_pages_contig+475\n cow_file_range_inline.constprop.0+230\n cow_file_range+803\n btrfs_run_delalloc_range+566\n writepage_delalloc+332\n __extent_writepage # inlined in my stacktrace, but I added it here\n extent_write_cache_pages+622\n\nLooking at the bisected-to pa\n---truncated---"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The vulnerable code is the btrfs buffered-write/writeback path, reached through ordinary local syscalls (write/close/fsync) on a mounted btrfs filesystem. No network protocol handling is involved, so local access to the machine is required.\nAC:L - The attacker fully controls the trigger \u2014 create a small (\u003c=2048 byte) file at offset 0 so the inline-extent path is taken, and drive cow_file_range_inline() to a negative return via attacker-inducible memory pressure (-ENOMEM in btrfs_alloc_path/btrfs_join_transaction) or on an already-aborted/EROFS filesystem where the failure is deterministic; the write/close loop can be repeated indefinitely until it fires.\nPR:L - Any unprivileged local user with write access to any btrfs filesystem (e.g. /home or /tmp) can reach the path; no capabilities, mount privileges, or user-namespace tricks are needed.\nUI:N - The attacker\u0027s own write and close trigger writeback via btrfs_release_file()-\u003efilemap_flush(), exactly as in the syzbot stack trace; no victim action is required.\nS:U - The corrupted state (folio lock bits, btrfs page-cache pages) and the resulting panic or hang are confined to the kernel of the same host, with no crossing of a VM, IOMMU, or other security authority boundary.\nC:H - The double unlock destroys page-lock mutual exclusion on a page-cache folio, letting a second thread operate on a folio concurrently with truncate/invalidate/reclaim and read data from a folio that can be freed and reused underneath it, a use-after-free style read primitive over page cache contents.\nI:H - With the page lock invariant broken, two threads can simultaneously believe they own a folio that is being started into writeback, allowing writes into a folio racing removal from the mapping and reuse, i.e. memory corruption leveragable beyond a mere crash.\nA:H - On kernels with CONFIG_BTRFS_ASSERT this is an immediate kernel BUG/panic at fs/btrfs/subpage.c:871; otherwise folio_unlock()\u0027s xor re-sets PG_locked on an ownerless folio, wedging every future access to that page in an unkillable D-state and blocking inode eviction and unmount."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T11:36:11.043Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/061e41581606000a83ce0f0f01d6ad338f3704e9"
},
{
"url": "https://git.kernel.org/stable/c/478574370bef7951fbd9ef5155537d6cbed49472"
}
],
"title": "btrfs: make cow_file_range_inline() honor locked_page on error",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2024-42266",
"datePublished": "2024-08-17T08:54:22.308Z",
"dateReserved": "2024-07-30T07:40:12.259Z",
"dateUpdated": "2026-08-05T11:36:11.043Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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