Executive brief
A memory leak vulnerability was identified in the Linux kernel's batman-adv module, which is used for managing mesh networks. When the system fails to process certain network 'claims' during bridge loop avoidance, it fails to release internal references, leading to a gradual consumption of system memory. Over time, this could lead to system instability or a crash, potentially disrupting network operations.
Technical details
A reference leak exists in the 'batman-adv' kernel module within the Bridge Loop Avoidance (BLA) mechanism. Specifically, in the 'batadv_bla_add_claim()' function, if a new claim fails to be inserted into the hash table, the function returns without calling 'batadv_backbone_gw_put()'. This results in a leaked reference to the 'backbone_gw' object. An attacker on the local network segment could potentially trigger this error path repeatedly to exhaust kernel memory. The issue has been resolved by adding the missing 'put' call in the error handling path across multiple stable kernel branches.
Affected products
- Linux Linux kernel All versions prior to the May 2026 patches
Timeline
- 2026-05-06: other: Patch authored
- 2026-05-28: disclosed: CVE published
References
- https://git.kernel.org/stable/c/0baf4b659cdc7305cf685b5a5d60f9e3816ab5d0
- https://git.kernel.org/stable/c/65419eb4259a26a3cd3f56fa0e3b3c113bf8c256
- https://git.kernel.org/stable/c/7cccf4eb4f96d3c3af91a00b7a9caa652439542e
- https://git.kernel.org/stable/c/ba9d20ee9076dac32c371116bacbe72480eb356c
- https://git.kernel.org/stable/c/fd0ca034c1e71ca7613cde9dd892836b2c2831bd