CVE-2026-80731

CVE CVE-2026-80731EUVD EUVD-2026-70335Published 2026-09-03T08:21:48.000ZLast changed 2026-09-04T04:58:17.000ZCVSS 7.8

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header dev_validate_header() reads dev->hard_header_len directly when zero-padding short link layer headers for CAP_SYS_RAWIO holders: if (capable(CAP_SYS_RAWIO)) { memset(ll_header + len, 0, dev->hard_header_len - len); return true; } Packet send paths call dev_validate_header() on skbs whose headroom was allocated from an earlier hard_header_len read. If the device is reconfigured so that dev->hard_header_len increases before validation, the memset writes past the reserved buffer, an out-of-bounds write. This out-of-bounds write is masked in some SOCK_RAW paths today because the same concurrent increase can first make skb_push() exceed the reserved headroom and trigger skb_under_panic(). Remove the zero-padding branch before making those hard_header_len reads consistent, so the snapshot fixes do not turn a loud panic into a silent overwrite. This path is only reached for variable length L2 protocols, where len < hard_header_len but len >= min_header_len. No remaining in-tree variable length L2 protocol implements header_ops->validate, and the CAP_SYS_RAWIO bypass that zero-pads and accepts short headers has no real value beyond allowing testing of intentionally malformed input. Drop the CAP_SYS_RAWIO branch. The remaining reads of dev->hard_header_len in dev_validate_header() are comparisons only and have no memory safety impact.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux f58a6c08ebdfa978178bbca78c2ba744a2665912; patch: 6.6.152; 2793a23aacbd754dbbb5cb75093deb7e4103bace <3b9a324e646d3657a8d9806dfbfe4f3e4066e882; 2793a23aacbd754dbbb5cb75093deb7e4103bace <99df6b7a713f96eda206680d100b76e15f9d9b69; 1df16498dfd0d5a129bdf2982d9a08df73e8923d; patch: 5.15.216; 3.16.36 <3.17; 2793a23aacbd754dbbb5cb75093deb7e4103bace <8fc9816404166a90ed8d544dc52482fafffb6d9f; 4.6; 2793a23aacbd754dbbb5cb75093deb7e4103bace <dbb30dc943a93e083f1e531bfdc6779e57de40d0; patch: 0; 2793a23aacbd754dbbb5cb75093deb7e4103bace <fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6; patch: 7.1.9; patch: 6.12.104; 6804052fa9d86e9a512c88b24a5debbfc1a490fc; 2793a23aacbd754dbbb5cb75093deb7e4103bace <74e035f07f53feca09e2352e77fccb09cad5e208; 8b8d278aa4de9335682bbd4a3bb619af015c859e; 4.5.2 <4.6; 2793a23aacbd754dbbb5cb75093deb7e4103bace <fc902f52a02298c7432b2334c0c82a2885a1a8b6; patch: 6.18.45; b5518429e70cd783b8ca52335456172c1a0589f6 <53fd7f912c0877647d6a1e1877f5ea8535ee0b4a; patch: 6.1.183; 3.2.80 <3.2.81; 4.1.28 <4.2; 4.4.8 <4.5; 2793a23aacbd754dbbb5cb75093deb7e4103bace <b0f92a5731dc82556a9ae005cc35f71ab136307b; patch: 7.2; patch: 5.10.265; patch: 3.2.81

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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