CVE-2026-52919

batman-adv: fix tp_meter counter underflow during shutdown

State: Published
Severity: 7.8 High
Published: Jun 24, 2026
Updated: Aug 5, 2026
Reserved: Jun 9, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

batman-adv: fix tp_meter counter underflow during shutdown

batadv_tp_sender_shutdown() unconditionally decrements the "sending" atomic counter. If multiple paths (e.g. timeout, user cancel, and normal finish) call this function, the counter can underflow to -1.

Since the sender logic treats any non-zero value as "still sending", a negative value causes the sender kthread to loop indefinitely. This leads to a use-after-free when the interface is removed while the zombie thread is still active.

Fix this by using atomic_xchg() to ensure the counter only transitions from 1 to 0 once.

[sven: added missing change in batadv_tp_send]

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before e75e2ab463b5b34df6b98f94d740aff327ce9f6bAffected 33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before abae88fa254f2981d39ac003a7b302528a22af64Affected 33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before c66d20a3ff095e3f000551d208ec2606616db15cAffected 33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before c1bac194733aabd731aafa6a01350c229e187dbaAffected 33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before 01cefc5923889e29dbb5f281c3d457714ceb9c00Affected 33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before 90ae3eae06b7b8ab9f6250b9497c860915b4c17bAffected 33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before aeae11c5dad9cd0d50723890bdd866f8e6db2e7dAffected 33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before 94f3b133168d1c49895e7cc6afbcf1cc0b354602Affected
LinuxLinux	4.8Affected before 4.8Not affected 5.10.258 through 5.10.Not affected 5.15.209 through 5.15.Not affected 6.1.175 through 6.1.Not affected 6.6.142 through 6.6.Not affected 6.12.92 through 6.12.Not affected 6.18.34 through 6.18.Not affected 7.0.11 through 7.0.*Not affected 7.1 and laterNot affected

Product

Versions

LinuxLinux

33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before e75e2ab463b5b34df6b98f94d740aff327ce9f6bAffected
33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before abae88fa254f2981d39ac003a7b302528a22af64Affected
33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before c66d20a3ff095e3f000551d208ec2606616db15cAffected
33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before c1bac194733aabd731aafa6a01350c229e187dbaAffected
33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before 01cefc5923889e29dbb5f281c3d457714ceb9c00Affected
33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before 90ae3eae06b7b8ab9f6250b9497c860915b4c17bAffected
33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before aeae11c5dad9cd0d50723890bdd866f8e6db2e7dAffected
33a3bb4a3345bb511f9c69c913da95d4693e2a4e to before 94f3b133168d1c49895e7cc6afbcf1cc0b354602Affected

LinuxLinux

4.8Affected
before 4.8Not affected
5.10.258 through 5.10.*Not affected
5.15.209 through 5.15.*Not affected
6.1.175 through 6.1.*Not affected
6.6.142 through 6.6.*Not affected
6.12.92 through 6.12.*Not affected
6.18.34 through 6.18.*Not affected
7.0.11 through 7.0.*Not affected
7.1 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.