NetSight
medium5.5

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 enabl…

Impact

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.

Affected products

VendorProductAffected versions
LinuxLinux Kernel
from 5.4 before 5.4.297
from 5.5 before 5.10.241
from 5.11 before 5.15.190
from 5.16 before 6.1.149
from 6.2 before 6.6.103
from 6.7 before 6.12.43
DebianDebian Linux
Version 11.0

Weakness classification

References