CVE-2025-39736

Summary

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.

Impact & exploitability

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products we track (2)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/08f70be5e406ce47c822f2dd11c1170ca259605b ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/08f70be5e406ce47c822f2dd11c1170ca259605bPatch
• https://git.kernel.org/stable/c/1da95d3d4b7b1d380ebd87b71a61e7e6aed3265dPatch
• https://git.kernel.org/stable/c/47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2Patch
• https://git.kernel.org/stable/c/4b0151e1d468eb2667c37b7af99b3c075072d334Patch
• https://git.kernel.org/stable/c/62879faa8efe8d8a9c7bf7606ee9c068012d7dacPatch
• https://git.kernel.org/stable/c/a0854de00ce2ee27edf39037e7836ad580eb3350Patch
• https://git.kernel.org/stable/c/a181b228b37a6a5625dad2bb4265bb7abb673e9fPatch
• https://git.kernel.org/stable/c/c7b6ea0ede687e7460e593c5ea478f50aa41682aPatch