AZL-67172
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-67172.json
- JSON Data
- https://api.osv.dev/v1/vulns/AZL-67172
- Upstream
- Published
- 2025-09-11T17:15:34Z
- Modified
- 2026-04-21T04:38:05Z
- 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 pr_warn() outside kmemleak_lock
When netpoll is enabled, calling pr_warn_once() while holding kmemleak_lock in mem_pool_alloc() can cause a deadlock due to lock inversion with the netconsole subsystem. This occurs because pr_warn_once() may trigger netpoll, which eventually leads to __alloc_skb() and back into kmemleak code, attempting to reacquire kmemleak_lock.
This is the path for the deadlock.
mem_pool_alloc() -> raw_spin_lock_irqsave(&kmemleak_lock, flags); -> pr_warn_once() -> netconsole subsystem -> netpoll -> __alloc_skb -> __create_object -> raw_spin_lock_irqsave(&kmemleak_lock, flags);
Fix this by setting a flag and issuing the pr_warn_once() after kmemleak_lock is released.
- References