CVE-2026-31659

Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: reject oversized global TT response buffers batadv_tt_prepare_tvlv_global_data() builds the allocation length for a global TT response in 16-bit temporaries. When a remote originator advertises a large enough global TT, the TT payload length plus the VLAN header offset can exceed 65535 and wrap before kmalloc(). The full-table response path still uses the original TT payload length when it fills tt_change, so the wrapped allocation is too small and batadv_tt_prepare_tvlv_global_data() writes past the end of the heap object before the later packet-size check runs. Fix this by rejecting TT responses whose TVLV value length cannot fit in the 16-bit TVLV payload length field.

References

• https://git.kernel.org/stable/c/2997f4bd1f982e7013709946e00be89b507693fa
• https://git.kernel.org/stable/c/3a359bf5c61d52e7f09754108309d637532164a6
• https://git.kernel.org/stable/c/69d61639bc7e963c3b645e570279d731e7c89062
• https://git.kernel.org/stable/c/7e5d007e0df946bffb8542fb112e0044014a5897
• https://git.kernel.org/stable/c/95c71365a2222908441b54d6f2c315e0c79fcec3