CVE-2025-39736
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…
Does this matter?
Lower severity and a low EPSS score (0.13%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-667
- Affected
- linux/linux kernel · debian/debian linux
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- 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
- https://git.kernel.org/stable/c/f249d32bb54876b4b6c3ae071af8ddca77af390bPatch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlMailing List, Third Party Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.