CVE-2025-39736
mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock
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.
INFO
Published Date :
Sept. 11, 2025, 5:15 p.m.
Last Modified :
Jan. 9, 2026, 2:59 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Linux kernel to include the fix.
- Avoid deadlocks by moving pr_warn_once() outside kmemleak_lock.
- Test the fix to ensure deadlock is resolved.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-39736.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-39736 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-39736
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-39736 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-39736 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jan. 09, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-667 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.103 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.43 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.190 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.241 *cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.15.11 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.16 up to (excluding) 6.16.2 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.149 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.4 up to (excluding) 5.4.297 Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Added Reference Type kernel.org: https://git.kernel.org/stable/c/08f70be5e406ce47c822f2dd11c1170ca259605b Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/4b0151e1d468eb2667c37b7af99b3c075072d334 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/62879faa8efe8d8a9c7bf7606ee9c068012d7dac Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a0854de00ce2ee27edf39037e7836ad580eb3350 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a181b228b37a6a5625dad2bb4265bb7abb673e9f Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c7b6ea0ede687e7460e593c5ea478f50aa41682a Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/f249d32bb54876b4b6c3ae071af8ddca77af390b Types: Patch Added Reference Type CVE: https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Types: Mailing List, Third Party Advisory Added Reference Type CVE: https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Types: Mailing List, Third Party Advisory -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 03, 2025
Action Type Old Value New Value Added Reference https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Added Reference https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 11, 2025
Action Type Old Value New Value Added 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. Added Reference https://git.kernel.org/stable/c/08f70be5e406ce47c822f2dd11c1170ca259605b Added Reference https://git.kernel.org/stable/c/1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d Added Reference https://git.kernel.org/stable/c/47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2 Added Reference https://git.kernel.org/stable/c/4b0151e1d468eb2667c37b7af99b3c075072d334 Added Reference https://git.kernel.org/stable/c/62879faa8efe8d8a9c7bf7606ee9c068012d7dac Added Reference https://git.kernel.org/stable/c/a0854de00ce2ee27edf39037e7836ad580eb3350 Added Reference https://git.kernel.org/stable/c/a181b228b37a6a5625dad2bb4265bb7abb673e9f Added Reference https://git.kernel.org/stable/c/c7b6ea0ede687e7460e593c5ea478f50aa41682a Added Reference https://git.kernel.org/stable/c/f249d32bb54876b4b6c3ae071af8ddca77af390b