CVE-2026-52919
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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]
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.12% probability · 2th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-191
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/01cefc5923889e29dbb5f281c3d457714ceb9c00Patch
- https://git.kernel.org/stable/c/90ae3eae06b7b8ab9f6250b9497c860915b4c17bPatch
- https://git.kernel.org/stable/c/94f3b133168d1c49895e7cc6afbcf1cc0b354602Patch
- https://git.kernel.org/stable/c/abae88fa254f2981d39ac003a7b302528a22af64Patch
- https://git.kernel.org/stable/c/aeae11c5dad9cd0d50723890bdd866f8e6db2e7dPatch
- https://git.kernel.org/stable/c/c1bac194733aabd731aafa6a01350c229e187dbaPatch
- https://git.kernel.org/stable/c/c66d20a3ff095e3f000551d208ec2606616db15cPatch
- https://git.kernel.org/stable/c/e75e2ab463b5b34df6b98f94d740aff327ce9f6bPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.