CVE-2026-31659

NameCVE-2026-31659
DescriptionIn 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-4561-1, DSA-6238-1, DSA-6243-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bullseye5.10.223-1vulnerable
bullseye (security)5.10.251-5vulnerable
bookworm6.1.159-1vulnerable
bookworm (security)6.1.172-1fixed
trixie6.12.73-1vulnerable
trixie (security)6.12.88-1fixed
forky7.0.4-1fixed
sid7.0.7-1fixed
linux-6.1 (PTS)bullseye (security)6.1.170-3~deb11u1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebookworm6.1.170-1DSA-6243-1
linuxsourcetrixie6.12.85-1DSA-6238-1
linuxsource(unstable)6.19.13-1
linux-6.1sourcebullseye6.1.170-1~deb11u1DLA-4561-1

Notes

https://git.kernel.org/linus/3a359bf5c61d52e7f09754108309d637532164a6 (7.0)

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