CVE-2025-23131: Linux kernel · dlm: prevent NPD when writing a positive value to event_done
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 5 Nov 2026, 23:23 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 16 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: dlm: prevent NPD when writing a positive value to event_done do_uevent returns the value written to event_done. In case it is a positive value, new_lockspace would undo all the work, and lockspace would not be set. __dlm_new_lockspace, however, would treat that positive value as a success due to commit 8511a2728ab8 ("dlm: fix use count with multiple joins"). Down the line, device_create_lockspace would pass that NULL lockspace to dlm_find_lockspace_local, leading to a NULL pointer dereference. Treating such positive values as successes prevents the problem. Given this has been broken for so long, this is unlikely to break userspace expectations.
References
- git.kernel.org/stable/c/a1c41aebb184d9228a440dcb6761224e65b0e49a (opens in a new tab)
- git.kernel.org/stable/c/ee28d99d789b077565cbe0377374d1e826c64d93 (opens in a new tab)
- git.kernel.org/stable/c/c7837e2c96559663c33f43da403d9cf3cf77cfa7 (opens in a new tab)
- git.kernel.org/stable/c/7109d69bec6edce546dc870e66bd2b668a3d5549 (opens in a new tab)
- git.kernel.org/stable/c/10b7a59814765d18d43555c9cef4eb3048b7e8a3 (opens in a new tab)
- git.kernel.org/stable/c/b73c4ad4d387fe5bc988145bd9f1bc0de76afd5c (opens in a new tab)
- git.kernel.org/stable/c/8e2bad543eca5c25cd02cbc63d72557934d45f13 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)