CVE-2026-74318 (GCVE-0-2026-74318)
Vulnerability from cvelistv5
Published
2026-08-15 05:58
Modified
2026-08-17 05:17
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix deadlock cloning inline extent when using flushoncommit
In commit b48c980b6a7e ("btrfs: fix deadlock between reflink and
transaction commit when using flushoncommit") a deadlock was fixed
between reflinks and transaction commits when the fs is mounted with the
flushoncommit option. This happened when we had to copy an inline extent's
data to the destination file. However the issue was fixed only for the
case where the destination offset is 0, it missed the case when the offset
is greater than zero.
Fix this by ensuring we get i_size update whenever we copied an inline
extent's data into the destination file.
Syzbot reported this with the following trace:
INFO: task kworker/u8:3:57 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3 state:D stack:21600 pid:57 tgid:57 ppid:2 task_flags:0x4208160 flags:0x00080000
Workqueue: writeback wb_workfn (flush-btrfs-129)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
wait_extent_bit fs/btrfs/extent-io-tree.c:905 [inline]
btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:2008
btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline]
btrfs_invalidate_folio+0x440/0xc00 fs/btrfs/inode.c:7718
extent_writepage fs/btrfs/extent_io.c:1848 [inline]
extent_write_cache_pages fs/btrfs/extent_io.c:2552 [inline]
btrfs_writepages+0x12f3/0x2410 fs/btrfs/extent_io.c:2684
do_writepages+0x32e/0x550 mm/page-writeback.c:2571
__writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056
wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241
wb_do_writeback fs/fs-writeback.c:2388 [inline]
wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428
process_one_work+0x98b/0x1630 kernel/workqueue.c:3318
process_scheduled_works kernel/workqueue.c:3401 [inline]
worker_thread+0xb49/0x1140 kernel/workqueue.c:3482
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
INFO: task syz.0.145:8523 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.145 state:D stack:22752 pid:8523 tgid:8522 ppid:5850 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847
try_to_writeback_inodes_sb+0x9a/0xc0 fs/fs-writeback.c:2895
btrfs_start_delalloc_flush fs/btrfs/transaction.c:2182 [inline]
btrfs_commit_transaction+0x813/0x2fc0 fs/btrfs/transaction.c:2371
btrfs_sync_file+0xdf4/0x1230 fs/btrfs/file.c:1822
generic_write_sync include/linux/fs.h:2663 [inline]
btrfs_do_write_iter+0x6a9/0x840 fs/btrfs/file.c:1473
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x629/0xba0 fs/read_write.c:688
ksys_write+0x156/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a0bdece59
RSP: 002b:00007f5a0b446028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5a0c065fa0 RCX: 00007f5a0bdece59
RDX: 000000000000029f RSI: 0000200000
---truncated---
References
| URL | Tags | |
|---|---|---|
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/btrfs/reflink.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "06283034cec0fa357cbd85784ef7d3f5b2ce0790",
"status": "affected",
"version": "05a5a7621ce66c142e081ffc24dd6ade6e912061",
"versionType": "git"
},
{
"lessThan": "2aa37c8ef1092c6f088e23a90bffefc672831c09",
"status": "affected",
"version": "05a5a7621ce66c142e081ffc24dd6ade6e912061",
"versionType": "git"
},
{
"lessThan": "ea3452726ccb6bcaa732f43cc57bb928eca3dd59",
"status": "affected",
"version": "05a5a7621ce66c142e081ffc24dd6ade6e912061",
"versionType": "git"
},
{
"lessThan": "532085d00eb54c074bdeae648b194765239f4d11",
"status": "affected",
"version": "05a5a7621ce66c142e081ffc24dd6ade6e912061",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/btrfs/reflink.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.7"
},
{
"lessThan": "5.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.97",
"versionStartIncluding": "5.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.40",
"versionStartIncluding": "5.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "5.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "5.7",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix deadlock cloning inline extent when using flushoncommit\n\nIn commit b48c980b6a7e (\"btrfs: fix deadlock between reflink and\ntransaction commit when using flushoncommit\") a deadlock was fixed\nbetween reflinks and transaction commits when the fs is mounted with the\nflushoncommit option. This happened when we had to copy an inline extent\u0027s\ndata to the destination file. However the issue was fixed only for the\ncase where the destination offset is 0, it missed the case when the offset\nis greater than zero.\n\nFix this by ensuring we get i_size update whenever we copied an inline\nextent\u0027s data into the destination file.\n\nSyzbot reported this with the following trace:\n\n INFO: task kworker/u8:3:57 blocked for more than 143 seconds.\n Not tainted syzkaller #0\n \"echo 0 \u003e /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n task:kworker/u8:3 state:D stack:21600 pid:57 tgid:57 ppid:2 task_flags:0x4208160 flags:0x00080000\n Workqueue: writeback wb_workfn (flush-btrfs-129)\n Call Trace:\n \u003cTASK\u003e\n context_switch kernel/sched/core.c:5402 [inline]\n __schedule+0x16f9/0x5500 kernel/sched/core.c:7204\n __schedule_loop kernel/sched/core.c:7283 [inline]\n schedule+0x164/0x360 kernel/sched/core.c:7298\n wait_extent_bit fs/btrfs/extent-io-tree.c:905 [inline]\n btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:2008\n btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline]\n btrfs_invalidate_folio+0x440/0xc00 fs/btrfs/inode.c:7718\n extent_writepage fs/btrfs/extent_io.c:1848 [inline]\n extent_write_cache_pages fs/btrfs/extent_io.c:2552 [inline]\n btrfs_writepages+0x12f3/0x2410 fs/btrfs/extent_io.c:2684\n do_writepages+0x32e/0x550 mm/page-writeback.c:2571\n __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764\n writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056\n wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241\n wb_do_writeback fs/fs-writeback.c:2388 [inline]\n wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428\n process_one_work+0x98b/0x1630 kernel/workqueue.c:3318\n process_scheduled_works kernel/workqueue.c:3401 [inline]\n worker_thread+0xb49/0x1140 kernel/workqueue.c:3482\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n \u003c/TASK\u003e\n INFO: task syz.0.145:8523 blocked for more than 143 seconds.\n Not tainted syzkaller #0\n \"echo 0 \u003e /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n task:syz.0.145 state:D stack:22752 pid:8523 tgid:8522 ppid:5850 task_flags:0x400140 flags:0x00080002\n Call Trace:\n \u003cTASK\u003e\n context_switch kernel/sched/core.c:5402 [inline]\n __schedule+0x16f9/0x5500 kernel/sched/core.c:7204\n __schedule_loop kernel/sched/core.c:7283 [inline]\n schedule+0x164/0x360 kernel/sched/core.c:7298\n wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227\n __writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847\n try_to_writeback_inodes_sb+0x9a/0xc0 fs/fs-writeback.c:2895\n btrfs_start_delalloc_flush fs/btrfs/transaction.c:2182 [inline]\n btrfs_commit_transaction+0x813/0x2fc0 fs/btrfs/transaction.c:2371\n btrfs_sync_file+0xdf4/0x1230 fs/btrfs/file.c:1822\n generic_write_sync include/linux/fs.h:2663 [inline]\n btrfs_do_write_iter+0x6a9/0x840 fs/btrfs/file.c:1473\n new_sync_write fs/read_write.c:595 [inline]\n vfs_write+0x629/0xba0 fs/read_write.c:688\n ksys_write+0x156/0x270 fs/read_write.c:740\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7f5a0bdece59\n RSP: 002b:00007f5a0b446028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001\n RAX: ffffffffffffffda RBX: 00007f5a0c065fa0 RCX: 00007f5a0bdece59\n RDX: 000000000000029f RSI: 0000200000\n---truncated---"
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:17:08.156Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/06283034cec0fa357cbd85784ef7d3f5b2ce0790"
},
{
"url": "https://git.kernel.org/stable/c/2aa37c8ef1092c6f088e23a90bffefc672831c09"
},
{
"url": "https://git.kernel.org/stable/c/ea3452726ccb6bcaa732f43cc57bb928eca3dd59"
},
{
"url": "https://git.kernel.org/stable/c/532085d00eb54c074bdeae648b194765239f4d11"
}
],
"title": "btrfs: fix deadlock cloning inline extent when using flushoncommit",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74318",
"datePublished": "2026-08-15T05:58:15.499Z",
"dateReserved": "2026-08-15T05:44:03.884Z",
"dateUpdated": "2026-08-17T05:17:08.156Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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