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.

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

No data.

No data.

References
Link Providers
https://git.kernel.org/stable/c/08f70be5e406ce47c822f2dd11c1170ca259605b cve-icon cve-icon
https://git.kernel.org/stable/c/1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d cve-icon cve-icon
https://git.kernel.org/stable/c/47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2 cve-icon cve-icon
https://git.kernel.org/stable/c/4b0151e1d468eb2667c37b7af99b3c075072d334 cve-icon cve-icon
https://git.kernel.org/stable/c/62879faa8efe8d8a9c7bf7606ee9c068012d7dac cve-icon cve-icon
https://git.kernel.org/stable/c/a0854de00ce2ee27edf39037e7836ad580eb3350 cve-icon cve-icon
https://git.kernel.org/stable/c/a181b228b37a6a5625dad2bb4265bb7abb673e9f cve-icon cve-icon
https://git.kernel.org/stable/c/c7b6ea0ede687e7460e593c5ea478f50aa41682a cve-icon cve-icon
https://git.kernel.org/stable/c/f249d32bb54876b4b6c3ae071af8ddca77af390b cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025091136-CVE-2025-39736-8dfc@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-39736 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-39736 cve-icon
History

Fri, 12 Sep 2025 08:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Fri, 12 Sep 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low

Thu, 11 Sep 2025 17:00:00 +0000

Type Values Removed Values 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.
Title mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-09-11T16:52:11.772Z

Updated: 2025-09-11T16:52:11.772Z

Reserved: 2025-04-16T07:20:57.119Z

Link: CVE-2025-39736

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-09-11T17:15:34.840

Modified: 2025-09-11T17:15:34.840

Link: CVE-2025-39736

cve-icon Redhat

Severity : Low

Publid Date: 2025-09-11T00:00:00Z

Links: CVE-2025-39736 - Bugzilla