CVE-2026-64088

batman-adv: tt: fix negative tt_buff_len

State: Published
Severity: 8.8 High
Published: Jul 19, 2026
Updated: Aug 5, 2026
Reserved: Jul 19, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

batman-adv: tt: fix negative tt_buff_len

batadv_orig_node::tt_buff_len was declared as s16, but the field is never intended to hold a negative value. When a value greater than 32767 is assigned, it wraps to a negative signed integer.

In batadv_send_other_tt_response(), tt_buff_len is temporarily widened to s32. The incorrectly negative s16 value propagates into the s32, causing batadv_tt_prepare_tvlv_global_data() to allocate a full sized buffer but populates only a small portion of it with the collected changeset. All remaining bits are kept uninitialized.

Using an u16 avoids this type confusion and ensures that no (negative) sign extension is performed in batadv_send_other_tt_response().

Scores

CVSS	Score	Vector	Source
3.1	8.8 High	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 4c4c2f340f4c27373bfcac8dc5032ce7bb474e47Affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430Affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 3c96dff00998314983b68a3e7caac07a66ebe496Affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 32edd2a28e112064020a2f319a8cb8a9e5a09767Affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 4dab98961426d0cf6a1599cda6950b7596ca2fcdAffected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 730de8733dd90f70d7580a9b329b971f8e1474a2Affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before ed28ead3420c373a7928622f114bc6168075d1e1Affected a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before b64963a2ceeb7529310b6cf253a1e540784422f4Affected
LinuxLinux	3.1Affected before 3.1Not affected 5.10.258 through 5.10.Not affected 5.15.209 through 5.15.Not affected 6.1.175 through 6.1.Not affected 6.6.142 through 6.6.Not affected 6.12.92 through 6.12.Not affected 6.18.34 through 6.18.Not affected 7.0.11 through 7.0.*Not affected 7.1 and laterNot affected

Product

Versions

LinuxLinux

a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 4c4c2f340f4c27373bfcac8dc5032ce7bb474e47Affected
a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 33e5ede7ce6d92e531920d4bbd6d3e18ef1c6430Affected
a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 3c96dff00998314983b68a3e7caac07a66ebe496Affected
a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 32edd2a28e112064020a2f319a8cb8a9e5a09767Affected
a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 4dab98961426d0cf6a1599cda6950b7596ca2fcdAffected
a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before 730de8733dd90f70d7580a9b329b971f8e1474a2Affected
a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before ed28ead3420c373a7928622f114bc6168075d1e1Affected
a73105b8d4c765d9ebfb664d0a66802127d8e4c7 to before b64963a2ceeb7529310b6cf253a1e540784422f4Affected

LinuxLinux

3.1Affected
before 3.1Not affected
5.10.258 through 5.10.*Not affected
5.15.209 through 5.15.*Not affected
6.1.175 through 6.1.*Not affected
6.6.142 through 6.6.*Not affected
6.12.92 through 6.12.*Not affected
6.18.34 through 6.18.*Not affected
7.0.11 through 7.0.*Not affected
7.1 and laterNot affected

References

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