CVE-2026-31659
Published: May 3, 2026Last modified: May 3, 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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 9.8 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.170-r0) |
| 25 LTS | linux-lts | Fixed (6.12.85-r0) | |
| Stream | linux-lts | Fixed (6.12.85-r0) |
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
- https://git.kernel.org/stable/c/cf2199171ef799ca7270019125f4a91bd20ad4d9
- https://git.kernel.org/stable/c/de6c1dc3c7d01a152607e6fcecee4d5288283f10
- https://git.kernel.org/stable/c/f970646b9a39539d1bac86822ac78b5915455ea9