CVE-2026-31659

batman-adv: reject oversized global TT response buffers

State: Published
Severity: 9.8 Critical
Published: Apr 24, 2026
Updated: Oct 19, 2026
Reserved: Mar 9, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-190 Integer Overflow or Wraparound

Affected Products

Product	Versions
LinuxLinux	7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 7e5d007e0df946bffb8542fb112e0044014a5897Affected 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 2997f4bd1f982e7013709946e00be89b507693faAffected 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 95c71365a2222908441b54d6f2c315e0c79fcec3Affected 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 69d61639bc7e963c3b645e570279d731e7c89062Affected 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before f970646b9a39539d1bac86822ac78b5915455ea9Affected 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before de6c1dc3c7d01a152607e6fcecee4d5288283f10Affected 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before cf2199171ef799ca7270019125f4a91bd20ad4d9Affected 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 3a359bf5c61d52e7f09754108309d637532164a6Affected
LinuxLinux	3.13Affected before 3.13Not affected 5.10.253 through 5.10.Not affected 5.15.203 through 5.15.Not affected 6.1.169 through 6.1.Not affected 6.6.135 through 6.6.Not affected 6.12.82 through 6.12.Not affected 6.18.23 through 6.18.Not affected 6.19.13 through 6.19.*Not affected 7.0 and laterNot affected

Product

Versions

LinuxLinux

7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 7e5d007e0df946bffb8542fb112e0044014a5897Affected
7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 2997f4bd1f982e7013709946e00be89b507693faAffected
7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 95c71365a2222908441b54d6f2c315e0c79fcec3Affected
7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 69d61639bc7e963c3b645e570279d731e7c89062Affected
7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before f970646b9a39539d1bac86822ac78b5915455ea9Affected
7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before de6c1dc3c7d01a152607e6fcecee4d5288283f10Affected
7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before cf2199171ef799ca7270019125f4a91bd20ad4d9Affected
7ea7b4a142758deaf46c1af0ca9ceca6dd55138b to before 3a359bf5c61d52e7f09754108309d637532164a6Affected

LinuxLinux

3.13Affected
before 3.13Not affected
5.10.253 through 5.10.*Not affected
5.15.203 through 5.15.*Not affected
6.1.169 through 6.1.*Not affected
6.6.135 through 6.6.*Not affected
6.12.82 through 6.12.*Not affected
6.18.23 through 6.18.*Not affected
6.19.13 through 6.19.*Not affected
7.0 and laterNot affected

References

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