CVE-2026-90160

CVE CVE-2026-90160EUVD EUVD-2026-81753Published 2026-09-17T16:06:51.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: lwt_bpf: Restore reserved headroom after xmit program ip_finish_output2() expands an skb to LL_RESERVED_SPACE(dev) before LWT xmit. An LWT_XMIT BPF program can then modify the skb head and still return BPF_OK, so bpf_xmit() rechecks the remaining headroom before the skb continues to neighbour output. That recheck uses dst->dev->hard_header_len. This is not enough for the neighbour cached-header path: neigh_hh_output() copies the cached hardware header using the aligned hh_cache size, HH_DATA_MOD for short headers or HH_DATA_ALIGN(hh_len) otherwise. On Ethernet, hard_header_len is 14 but the cached copy needs 16 bytes. If an LWT_XMIT BPF program calls bpf_skb_change_head(skb, 1, 0), the skb can still have 15 bytes of headroom after the program. The existing check accepts that, after which neigh_hh_output() hits its headroom warning and drops the skb. Use LL_RESERVED_SPACE(dst->dev) in the post-BPF headroom check to match the reservation made before LWT xmit.

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 patch: 5.10.270; patch: 7.2.6; patch: 6.18.52; 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 <de2b2004e16f2930eb689175e2c1998b0a68d499; patch: 5.15.221; patch: 6.12.110; patch: 6.6.157; 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 <753e5cdcca5474d230d62bb3489e5168ab27c272; 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 <7cf561843ed0ad57501892a65abb77957e6c800f; 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 <a38c0eb447e2dd0120a2ebcdba470f9505ac8907; 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 <5fe7007aed9ad069b2bd77e5d0c875c64f5c0269; 4.10; 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 <7d043e24520a273c362be5dd7d9c82796879a49b; patch: 6.1.188; patch: 0; patch: 7.3-rc1; 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 <179a5b2171573d94a25c9aa8e1c9f9ac352ad316; 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 <c488071c3441fa34f5a87cd6c12ce2cc6304f20e

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

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Linux — Linux

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