CVE-2025-23131

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.

Affected Software

References

• https://git.kernel.org/stable/c/8e2bad543eca5c25cd02cbc63d72557934d45f13
• https://git.kernel.org/stable/c/b73c4ad4d387fe5bc988145bd9f1bc0de76afd5c