5.5

CVE-2022-50534: dm thin: Use last transaction's pmd->root when commit failed

Analyzed
AliasesUBUNTU-CVE-2022-50534DEBIAN-CVE-2022-50534
Published 07-10-2025Last modified 11-05-2026

Vulnerability summary

CVE-2022-50534 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.5% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.16%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 9 · Related 7
RHSA-2023:2458RHSA-2023:2951SUSE-SU-2025:4111-1SUSE-SU-2025:4135-1SUSE-SU-2025:4139-1SUSE-SU-2025:4149-1

Timeline

  1. 07-10-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

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

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.16%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.16% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu120 products
  • linuxAll versions (No fix recorded) | < 4.15.0-208.220 | < 5.4.0-144.161 | < 5.15.0-69.76
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 4.15.0-1153.166 | < 5.4.0-1097.105 | < 5.15.0-1033.37
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < b35a22760aa5008d82533e59b0f0b5eb1b02d4e5 | ≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < 87d69b8824ca9b090f5a8ed47f758e8f6eecb871 | ≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < 3db757ffdd87ed8d7118b2250236a496502a660f | ≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < f758987ff0af3a4b5ee69e95cab6a5294e4367b0 | ≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < 94f01ecc2aa0be992865acc80ebb6701f731f955 | ≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < 4b710e8481ade7c9200e94d3018e99dc42a0a0e8 | ≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < a63ce4eca86fd207e3db07c00fb7ccf4adf1b230 | ≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < b91f481300e3a10eaf66b94fc39b740928762aaf | ≥ 991d9fa02da0dd1f843dc011376965e0c8c6c9b5, < 7991dbff6849f67e823b7cc0c15e5a90b0549b9f | 3.2
  • linux_kernel≥ 3.2, < 4.9.337 | ≥ 4.10, < 4.14.303 | ≥ 4.15, < 4.19.270 | ≥ 4.20, < 5.4.229 | ≥ 5.5, < 5.10.163 | ≥ 5.11, < 5.15.87 | ≥ 5.16, < 6.0.18 | ≥ 6.1, < 6.1.4
Debian1 product
  • linux< 6.1.4-1

3 vendors · 123 products

References

13 links
Show all 13 references