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]

A flaw was found in the `batman-adv` module of the Linux kernel. During the shutdown process of the `tp_meter` sender, an atomic counter can underflow due to multiple decrements. This can cause the sender kernel thread to loop indefinitely, leading to a use-after-free vulnerability if the associated network interface is removed. This issue could result in system instability or a denial of service.

Red Hat Enterprise Linux 10 Not affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Not affected kernel Red Hat Enterprise Linux 9 Not affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-52919 https://nvd.nist.gov/vuln/detail/CVE-2026-52919 https://lore.kernel.org/linux-cve-announce/2026062430-CVE-2026-52919-f17e@gregkh/T