CVE-2026-63834

Summary

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

batman-adv: tp_meter: restrict number of unacked list entries

When the unacked_list is unbound, an attacker could send messages with small lengths and appropriated seqno + gaps to force the receiver to allocate more and more unacked_list entries. And the end either causing an out-of-memory situation or increase the management overhead for the (large) list that significant portions of CPU cycles are wasted in searching through the list.

When limiting the list to a specific number, it is important to still correctly add a new entry to the list. But if the list became larger than the limit, the last entry of the list (with the highest seqno) must be dropped to still allow the earlier seqnos to finish and therefore to continue the process. Otherwise, the process might get stuck with too high seqnos which are not handled by batadv_tp_ack_unordered().

Affected Software

VendorProductVersion RangeStatus
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < 31a88792bfba142be3c9521538c1db805677381faffected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < 1111a3381bca2d1f084a07686bc783af5ab23df7affected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < 1c616b0be4bd8399d485e25e91859373b95d6013affected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < f8c499fd275e59203b77fca76ae6ef2d096c2133affected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < c6231d628d06d841bc1617b2f7034f5f39876b16affected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < 2233787658db859f0a9b83cb397cf783bb8be865affected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < 1fb8762600a393d1caccd63be5d07e1756982d68affected
LinuxLinux33a3bb4a3345bb511f9c69c913da95d4693e2a4e < e7c775110e1858e5a7471a23a9c9658c0af9df89affected
LinuxLinux4.8affected
LinuxLinux0 < 4.8unaffected
LinuxLinux5.10.260 <= 5.10.*unaffected
LinuxLinux5.15.211 <= 5.15.*unaffected
LinuxLinux6.1.177 <= 6.1.*unaffected
LinuxLinux6.6.144 <= 6.6.*unaffected
LinuxLinux6.12.95 <= 6.12.*unaffected
LinuxLinux6.18.38 <= 6.18.*unaffected
LinuxLinux7.1.3 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References