CVE-2025-39736

mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock

State: Published
Severity: Not scored
Published: Sep 11, 2025
Updated: May 12, 2026
Reserved: Apr 16, 2025

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	c5665868183fec689dbab9fb8505188b2c4f0757 to before c7b6ea0ede687e7460e593c5ea478f50aa41682aAffected c5665868183fec689dbab9fb8505188b2c4f0757 to before 4b0151e1d468eb2667c37b7af99b3c075072d334Affected c5665868183fec689dbab9fb8505188b2c4f0757 to before f249d32bb54876b4b6c3ae071af8ddca77af390bAffected c5665868183fec689dbab9fb8505188b2c4f0757 to before 62879faa8efe8d8a9c7bf7606ee9c068012d7dacAffected c5665868183fec689dbab9fb8505188b2c4f0757 to before 1da95d3d4b7b1d380ebd87b71a61e7e6aed3265dAffected c5665868183fec689dbab9fb8505188b2c4f0757 to before a0854de00ce2ee27edf39037e7836ad580eb3350Affected c5665868183fec689dbab9fb8505188b2c4f0757 to before 08f70be5e406ce47c822f2dd11c1170ca259605bAffected c5665868183fec689dbab9fb8505188b2c4f0757 to before a181b228b37a6a5625dad2bb4265bb7abb673e9fAffected c5665868183fec689dbab9fb8505188b2c4f0757 to before 47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2Affected
LinuxLinux	5.4Affected before 5.4Not affected 5.4.297 through 5.4.Not affected 5.10.241 through 5.10.Not affected 5.15.190 through 5.15.Not affected 6.1.149 through 6.1.Not affected 6.6.103 through 6.6.Not affected 6.12.43 through 6.12.Not affected 6.15.11 through 6.15.Not affected 6.16.2 through 6.16.Not affected 6.17 and laterNot affected

Product

Versions

LinuxLinux

c5665868183fec689dbab9fb8505188b2c4f0757 to before c7b6ea0ede687e7460e593c5ea478f50aa41682aAffected
c5665868183fec689dbab9fb8505188b2c4f0757 to before 4b0151e1d468eb2667c37b7af99b3c075072d334Affected
c5665868183fec689dbab9fb8505188b2c4f0757 to before f249d32bb54876b4b6c3ae071af8ddca77af390bAffected
c5665868183fec689dbab9fb8505188b2c4f0757 to before 62879faa8efe8d8a9c7bf7606ee9c068012d7dacAffected
c5665868183fec689dbab9fb8505188b2c4f0757 to before 1da95d3d4b7b1d380ebd87b71a61e7e6aed3265dAffected
c5665868183fec689dbab9fb8505188b2c4f0757 to before a0854de00ce2ee27edf39037e7836ad580eb3350Affected
c5665868183fec689dbab9fb8505188b2c4f0757 to before 08f70be5e406ce47c822f2dd11c1170ca259605bAffected
c5665868183fec689dbab9fb8505188b2c4f0757 to before a181b228b37a6a5625dad2bb4265bb7abb673e9fAffected
c5665868183fec689dbab9fb8505188b2c4f0757 to before 47b0f6d8f0d2be4d311a49e13d2fd5f152f492b2Affected

LinuxLinux

5.4Affected
before 5.4Not affected
5.4.297 through 5.4.*Not affected
5.10.241 through 5.10.*Not affected
5.15.190 through 5.15.*Not affected
6.1.149 through 6.1.*Not affected
6.6.103 through 6.6.*Not affected
6.12.43 through 6.12.*Not affected
6.15.11 through 6.15.*Not affected
6.16.2 through 6.16.*Not affected
6.17 and laterNot affected

References

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