PT-2025-38550 · Linux+7 · Linux Kernel+7

Published

2025-09-19

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Updated

2026-05-07

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CVE-2025-39843

CVSS v3.1

5.5

Medium

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description The set track prepare() function in the Linux kernel can incur lock recursion. This issue arises when called from hrtimer start range ns while holding the per cpu(hrtimer bases)[n].lock. When CONFIG DEBUG OBJECTS TIMERS is enabled, this can wake up kswapd within set track prepare(), attempting to re-acquire the same lock, leading to a deadlock. The issue is addressed by preventing kswapd from being woken up by passing allocation flags that do not contain GFP KSWAPD RECLAIM in the debug objects fill pool() case. The GFP DIRECT RECLAIM flag is also masked out within slab alloc() as it has preemption disabled.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Allocation of Resources Without Limits

Improper Locking

Weakness Enumeration

Related Identifiers

ALSA-2025:21926
ALSA-2026:0453
BDU:2025-14119
CVE-2025-39843
DLA-4328-1
DSA-6008-1
DSA-6009-1
ECHO-A49B-5A64-0E27
INFESA-2025_0006
INFSA-2025_21926
OESA-2026-1337
OESA-2026-1338
OESA-2026-1339
RHSA-2025:21926
RHSA-2025:23789
RHSA-2025_21926
RHSA-2026:0271
RHSA-2026:0453
USN-8095-1
USN-8095-2
USN-8095-3
USN-8095-4
USN-8095-5
USN-8100-1
USN-8125-1
USN-8126-1
USN-8165-1
USN-8261-1

Affected Products

Almalinux
Astra Linux
Debian
Linuxmint
Linux Kernel
Red Hat
Rocky Linux
Ubuntu