CVE-2026-52919

Summary

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]

Affected Software

VendorProductVersion RangeStatus
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < e75e2ab463b5b34df6b98f94d740aff327ce9f6baffected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < abae88fa254f2981d39ac003a7b302528a22af64affected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < c66d20a3ff095e3f000551d208ec2606616db15caffected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < c1bac194733aabd731aafa6a01350c229e187dbaaffected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < 01cefc5923889e29dbb5f281c3d457714ceb9c00affected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < 90ae3eae06b7b8ab9f6250b9497c860915b4c17baffected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < aeae11c5dad9cd0d50723890bdd866f8e6db2e7daffected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < 94f3b133168d1c49895e7cc6afbcf1cc0b354602affected
LinuxLinux4.8affected
LinuxLinux0 < 4.8unaffected
LinuxLinux5.10.258 <= 5.10.*unaffected
LinuxLinux5.15.209 <= 5.15.*unaffected
LinuxLinux6.1.175 <= 6.1.*unaffected
LinuxLinux6.6.142 <= 6.6.*unaffected
LinuxLinux6.12.92 <= 6.12.*unaffected
LinuxLinux6.18.34 <= 6.18.*unaffected
LinuxLinux7.0.11 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References