{"api_version":"1","generated_at":"2026-10-01T19:48:54+00:00","cve":"CVE-2026-90160","urls":{"html":"https://cve.report/CVE-2026-90160","api":"https://cve.report/api/cve/CVE-2026-90160.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-90160","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-90160"},"summary":{"title":"lwt_bpf: Restore reserved headroom after xmit program","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlwt_bpf: Restore reserved headroom after xmit program\n\nip_finish_output2() expands an skb to LL_RESERVED_SPACE(dev) before LWT\nxmit. An LWT_XMIT BPF program can then modify the skb head and still\nreturn BPF_OK, so bpf_xmit() rechecks the remaining headroom before the\nskb continues to neighbour output.\n\nThat recheck uses dst->dev->hard_header_len. This is not enough for the\nneighbour cached-header path: neigh_hh_output() copies the cached hardware\nheader using the aligned hh_cache size, HH_DATA_MOD for short headers or\nHH_DATA_ALIGN(hh_len) otherwise.\n\nOn Ethernet, hard_header_len is 14 but the cached copy needs 16 bytes. If\nan LWT_XMIT BPF program calls bpf_skb_change_head(skb, 1, 0), the skb can\nstill have 15 bytes of headroom after the program. The existing check\naccepts that, after which neigh_hh_output() hits its headroom warning and\ndrops the skb.\n\nUse LL_RESERVED_SPACE(dst->dev) in the post-BPF headroom check to match\nthe reservation made before LWT xmit.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-17 17:17:09","updated_at":"2026-09-17 17:17:09"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/a38c0eb447e2dd0120a2ebcdba470f9505ac8907","name":"https://git.kernel.org/stable/c/a38c0eb447e2dd0120a2ebcdba470f9505ac8907","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7cf561843ed0ad57501892a65abb77957e6c800f","name":"https://git.kernel.org/stable/c/7cf561843ed0ad57501892a65abb77957e6c800f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/753e5cdcca5474d230d62bb3489e5168ab27c272","name":"https://git.kernel.org/stable/c/753e5cdcca5474d230d62bb3489e5168ab27c272","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/de2b2004e16f2930eb689175e2c1998b0a68d499","name":"https://git.kernel.org/stable/c/de2b2004e16f2930eb689175e2c1998b0a68d499","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7d043e24520a273c362be5dd7d9c82796879a49b","name":"https://git.kernel.org/stable/c/7d043e24520a273c362be5dd7d9c82796879a49b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5fe7007aed9ad069b2bd77e5d0c875c64f5c0269","name":"https://git.kernel.org/stable/c/5fe7007aed9ad069b2bd77e5d0c875c64f5c0269","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c488071c3441fa34f5a87cd6c12ce2cc6304f20e","name":"https://git.kernel.org/stable/c/c488071c3441fa34f5a87cd6c12ce2cc6304f20e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/179a5b2171573d94a25c9aa8e1c9f9ac352ad316","name":"https://git.kernel.org/stable/c/179a5b2171573d94a25c9aa8e1c9f9ac352ad316","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-90160","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90160","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 753e5cdcca5474d230d62bb3489e5168ab27c272 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 c488071c3441fa34f5a87cd6c12ce2cc6304f20e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 a38c0eb447e2dd0120a2ebcdba470f9505ac8907 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2 de2b2004e16f2930eb689175e2c1998b0a68d499 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.221 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.188 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.157 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.110 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.52 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.6 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/core/lwt_bpf.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"753e5cdcca5474d230d62bb3489e5168ab27c272","status":"affected","version":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2","versionType":"git"},{"lessThan":"c488071c3441fa34f5a87cd6c12ce2cc6304f20e","status":"affected","version":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2","versionType":"git"},{"lessThan":"a38c0eb447e2dd0120a2ebcdba470f9505ac8907","status":"affected","version":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2","versionType":"git"},{"lessThan":"de2b2004e16f2930eb689175e2c1998b0a68d499","status":"affected","version":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2","versionType":"git"},{"lessThan":"7d043e24520a273c362be5dd7d9c82796879a49b","status":"affected","version":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2","versionType":"git"},{"lessThan":"7cf561843ed0ad57501892a65abb77957e6c800f","status":"affected","version":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2","versionType":"git"},{"lessThan":"179a5b2171573d94a25c9aa8e1c9f9ac352ad316","status":"affected","version":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2","versionType":"git"},{"lessThan":"5fe7007aed9ad069b2bd77e5d0c875c64f5c0269","status":"affected","version":"3a0af8fd61f90920f6fa04e4f1e9a6a73c1b4fd2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/core/lwt_bpf.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.10"},{"lessThan":"4.10","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.270","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.221","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.188","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.157","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.110","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.52","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.270","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.221","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.188","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.157","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.110","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.52","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.6","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"4.10","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlwt_bpf: Restore reserved headroom after xmit program\n\nip_finish_output2() expands an skb to LL_RESERVED_SPACE(dev) before LWT\nxmit. An LWT_XMIT BPF program can then modify the skb head and still\nreturn BPF_OK, so bpf_xmit() rechecks the remaining headroom before the\nskb continues to neighbour output.\n\nThat recheck uses dst->dev->hard_header_len. This is not enough for the\nneighbour cached-header path: neigh_hh_output() copies the cached hardware\nheader using the aligned hh_cache size, HH_DATA_MOD for short headers or\nHH_DATA_ALIGN(hh_len) otherwise.\n\nOn Ethernet, hard_header_len is 14 but the cached copy needs 16 bytes. If\nan LWT_XMIT BPF program calls bpf_skb_change_head(skb, 1, 0), the skb can\nstill have 15 bytes of headroom after the program. The existing check\naccepts that, after which neigh_hh_output() hits its headroom warning and\ndrops the skb.\n\nUse LL_RESERVED_SPACE(dst->dev) in the post-BPF headroom check to match\nthe reservation made before LWT xmit."}],"providerMetadata":{"dateUpdated":"2026-09-17T16:06:51.806Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/753e5cdcca5474d230d62bb3489e5168ab27c272"},{"url":"https://git.kernel.org/stable/c/c488071c3441fa34f5a87cd6c12ce2cc6304f20e"},{"url":"https://git.kernel.org/stable/c/a38c0eb447e2dd0120a2ebcdba470f9505ac8907"},{"url":"https://git.kernel.org/stable/c/de2b2004e16f2930eb689175e2c1998b0a68d499"},{"url":"https://git.kernel.org/stable/c/7d043e24520a273c362be5dd7d9c82796879a49b"},{"url":"https://git.kernel.org/stable/c/7cf561843ed0ad57501892a65abb77957e6c800f"},{"url":"https://git.kernel.org/stable/c/179a5b2171573d94a25c9aa8e1c9f9ac352ad316"},{"url":"https://git.kernel.org/stable/c/5fe7007aed9ad069b2bd77e5d0c875c64f5c0269"}],"title":"lwt_bpf: Restore reserved headroom after xmit program","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-90160","datePublished":"2026-09-17T16:06:51.806Z","dateReserved":"2026-09-11T19:38:34.790Z","dateUpdated":"2026-09-17T16:06:51.806Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-17 17:17:09","lastModifiedDate":"2026-09-17 17:17:09","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"90160","Ordinal":"1","Title":"lwt_bpf: Restore reserved headroom after xmit program","CVE":"CVE-2026-90160","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"90160","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nlwt_bpf: Restore reserved headroom after xmit program\n\nip_finish_output2() expands an skb to LL_RESERVED_SPACE(dev) before LWT\nxmit. An LWT_XMIT BPF program can then modify the skb head and still\nreturn BPF_OK, so bpf_xmit() rechecks the remaining headroom before the\nskb continues to neighbour output.\n\nThat recheck uses dst->dev->hard_header_len. This is not enough for the\nneighbour cached-header path: neigh_hh_output() copies the cached hardware\nheader using the aligned hh_cache size, HH_DATA_MOD for short headers or\nHH_DATA_ALIGN(hh_len) otherwise.\n\nOn Ethernet, hard_header_len is 14 but the cached copy needs 16 bytes. If\nan LWT_XMIT BPF program calls bpf_skb_change_head(skb, 1, 0), the skb can\nstill have 15 bytes of headroom after the program. The existing check\naccepts that, after which neigh_hh_output() hits its headroom warning and\ndrops the skb.\n\nUse LL_RESERVED_SPACE(dst->dev) in the post-BPF headroom check to match\nthe reservation made before LWT xmit.","Type":"Description","Title":"lwt_bpf: Restore reserved headroom after xmit program"}]}}}