CVE-2026-52919
HIGH 7.8In 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]
Severe if exploited (CVSS 7.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.1%chance of exploitation in 30 days · 2nd percentile
Impact if exploited
7.8CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Weakness (CWE)
Not classified.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Technical & other
- https://git.kernel.org/stable/c/e75e2ab463b5b34df6b98f94d740aff327ce9f6b
- https://git.kernel.org/stable/c/abae88fa254f2981d39ac003a7b302528a22af64
- https://git.kernel.org/stable/c/c66d20a3ff095e3f000551d208ec2606616db15c
- https://git.kernel.org/stable/c/c1bac194733aabd731aafa6a01350c229e187dba
- https://git.kernel.org/stable/c/01cefc5923889e29dbb5f281c3d457714ceb9c00
- https://git.kernel.org/stable/c/90ae3eae06b7b8ab9f6250b9497c860915b4c17b
- https://git.kernel.org/stable/c/aeae11c5dad9cd0d50723890bdd866f8e6db2e7d
- https://git.kernel.org/stable/c/94f3b133168d1c49895e7cc6afbcf1cc0b354602