Medium severity · published Sep 11, 2025
CVE-2025-39736
mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock
5.5
CVSS
0.1%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
5.4 before 5.4.297; 5.5 before 5.10.241; 5.11 before 5.15.190; 5.16 before 6.1.149; 6.2 before 6.6.103; 6.7 before 6.12.43; +3 more · source: NVD
LI
Linux · Linux
c5665868183fec689dbab9fb8505188b2c4f0757 before c7b6ea0ede687e7460e593c5ea478f50aa41682a; c5665868183fec689dbab9fb8505188b2c4f0757 before 4b0151e1d468eb2667c37b7af99b3c075072d334; c5665868183fec689dbab9fb8505188b2c4f0757 before f249d32bb54876b4b6c3ae071af8ddca77af390b; c5665868183fec689dbab9fb8505188b2c4f0757 before 62879faa8efe8d8a9c7bf7606ee9c068012d7dac; c5665868183fec689dbab9fb8505188b2c4f0757 before 1da95d3d4b7b1d380ebd87b71a61e7e6aed3265d; c5665868183fec689dbab9fb8505188b2c4f0757 before a0854de00ce2ee27edf39037e7836ad580eb3350; +4 more · source: vendor
DL
Debian Linux · Debian
11.0 · source: NVD
SC
SIMATIC CN 4100 · Siemens
before V5.0 · source: CISA