In the Linux kernel, the following vulnerability has been resolved:
dm thin: Use last transaction's pmd->root when commit failed
Recently we found a softlock up problem in dm thin pool btree lookup
code due to corrupted metadata:
Kernel panic - not syncing: softlockup: hung tasks
CPU: 7 PID: 2669225 Comm: kworker/u16:3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Workqueue: dm-thin do_worker [dm_thin_pool]
Call Trace:
<IRQ>
dump_stack+0x9c/0xd3
panic+0x35d/0x6b9
watchdog_timer_fn.cold+0x16/0x25
__run_hrtimer+0xa2/0x2d0
</IRQ>
RIP: 0010:__relink_lru+0x102/0x220 [dm_bufio]
__bufio_new+0x11f/0x4f0 [dm_bufio]
new_read+0xa3/0x1e0 [dm_bufio]
dm_bm_read_lock+0x33/0xd0 [dm_persistent_data]
ro_step+0x63/0x100 [dm_persistent_data]
btree_lookup_raw.constprop.0+0x44/0x220 [dm_persistent_data]
dm_btree_lookup+0x16f/0x210 [dm_persistent_data]
dm_thin_find_block+0x12c/0x210 [dm_thin_pool]
__process_bio_read_only+0xc5/0x400 [dm_thin_pool]
process_thin_deferred_bios+0x1a4/0x4a0 [dm_thin_pool]
process_one_work+0x3c5/0x730
Following process may generate a broken btree mixed with fresh and
stale btree nodes, which could get dm thin trapped in an infinite loop
while looking up data block:
Transaction 1: pmd->root = A, A->B->C // One path in btree
pmd->root = X, X->Y->Z // Copy-up
Transaction 2: X,Z is updated on disk, Y write failed.
// Commit failed, dm thin becomes read-only.
process_bio_read_only
dm_thin_find_block
__find_block
dm_btree_lookup(pmd->root)
The pmd->root points to a broken btree, Y may contain stale node
pointing to any block, for example X, which gets dm thin trapped into
a dead loop while looking up Z.
Fix this by setting pmd->root in __open_metadata(), so that dm thin
will use the last transaction's pmd->root if commit failed.
Fetch a reproducer in [Link].
Linke: https://bugzilla.kernel.org/show_bug.cgi?id=216790
References
Configurations
Configuration 1 (hide)
|
History
05 Feb 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/3db757ffdd87ed8d7118b2250236a496502a660f - Patch | |
| References | () https://git.kernel.org/stable/c/4b710e8481ade7c9200e94d3018e99dc42a0a0e8 - Patch | |
| References | () https://git.kernel.org/stable/c/7991dbff6849f67e823b7cc0c15e5a90b0549b9f - Patch | |
| References | () https://git.kernel.org/stable/c/87d69b8824ca9b090f5a8ed47f758e8f6eecb871 - Patch | |
| References | () https://git.kernel.org/stable/c/94f01ecc2aa0be992865acc80ebb6701f731f955 - Patch | |
| References | () https://git.kernel.org/stable/c/a63ce4eca86fd207e3db07c00fb7ccf4adf1b230 - Patch | |
| References | () https://git.kernel.org/stable/c/b35a22760aa5008d82533e59b0f0b5eb1b02d4e5 - Patch | |
| References | () https://git.kernel.org/stable/c/b91f481300e3a10eaf66b94fc39b740928762aaf - Patch | |
| References | () https://git.kernel.org/stable/c/f758987ff0af3a4b5ee69e95cab6a5294e4367b0 - Patch | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| First Time |
Linux
Linux linux Kernel |
|
| CWE | NVD-CWE-noinfo |
07 Oct 2025, 16:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-10-07 16:15
Updated : 2026-02-05 15:16
NVD link : CVE-2022-50534
Mitre link : CVE-2022-50534
CVE.ORG link : CVE-2022-50534
JSON object : View
Products Affected
linux
- linux_kernel
CWE