In the Linux kernel, the following vulnerability has been resolved:
dlm: prevent NPD when writing a positive value to event_done
douevent returns the value written to eventdone. In case it is a positive value, newlockspace would undo all the work, and lockspace would not be set. _dlmnewlockspace, however, would treat that positive value as a success due to commit 8511a2728ab8 ("dlm: fix use count with multiple joins").
Down the line, devicecreatelockspace would pass that NULL lockspace to dlmfindlockspace_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.
[
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"id": "CVE-2025-23131-305a8444",
"deprecated": false,
"signature_version": "v1",
"signature_type": "Line",
"target": {
"file": "fs/dlm/lockspace.c"
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"digest": {
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"threshold": 0.9
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"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@8e2bad543eca5c25cd02cbc63d72557934d45f13"
},
{
"id": "CVE-2025-23131-5d8a8716",
"deprecated": false,
"signature_version": "v1",
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{
"id": "CVE-2025-23131-c2c1b76f",
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"signature_version": "v1",
"signature_type": "Line",
"target": {
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"digest": {
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"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@b73c4ad4d387fe5bc988145bd9f1bc0de76afd5c"
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{
"id": "CVE-2025-23131-db781cd6",
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"signature_version": "v1",
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"target": {
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]