AZL-67172
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-67172.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/AZL-67172
- Upstream
- Published
- 2025-09-11T17:15:34Z
- Modified
- 2026-04-01T05:21:09.236326Z
- Summary
- CVE-2025-39736 affecting package kernel for versions less than 6.6.104.2-1
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
mm/kmemleak: avoid deadlock by moving prwarn() outside kmemleaklock
When netpoll is enabled, calling prwarnonce() while holding kmemleaklock in mempoolalloc() can cause a deadlock due to lock inversion with the netconsole subsystem. This occurs because prwarn_once() may trigger netpoll, which eventually leads to __allocskb() and back into kmemleak code, attempting to reacquire kmemleaklock.
This is the path for the deadlock.
mempoolalloc() -> rawspinlockirqsave(&kmemleaklock, flags); -> prwarnonce() -> netconsole subsystem -> netpoll -> __alloc_skb -> _createobject -> rawspinlockirqsave(&kmemleaklock, flags);
Fix this by setting a flag and issuing the prwarnonce() after kmemleak_lock is released.
- References