{"schema":"threatline.record/2","record":{"id":"CVE-2026-98368","aliases":[],"summary":"esp: downgrade zerocopy managed frags before mutating skb frags","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nesp: downgrade zerocopy managed frags before mutating skb frags\n\nOn the out-of-place output path (esp->inplace == false) ESP rewrites the\nskb frag array: esp_output_head() appends a trailer frag and\nesp_output_tail() replaces the frags with a destination page, both\nreferenced with get_page().\n\nWhen the skb carries zerocopy managed frags (SKBFL_MANAGED_FRAG_REFS) the\npayload frags are owned by the ubuf and must not be referenced or\nunreferenced individually, but ESP mutates the frag array without ever\ndowngrading the skb.  This breaks the managed-frag invariant two ways:\n\n  - esp_ssg_unref() walks the source scatterlist and drops a page\n    reference for every frag, including the ubuf-owned payload frags,\n    pushing their refcount below the GUP pin bias while the pages are\n    still pinned, i.e. a use-after-free of the zerocopy pages;\n\n  - esp_output_tail() installs its destination page as frag 0 with\n    get_page() but leaves SKBFL_MANAGED_FRAG_REFS set, so\n    skb_release_data() takes the skip_unref branch and never drops that\n    reference, leaking the x->xfrag page at packet rate.\n\nFix this the way every other frag-mutating site does (__ip_append_data(),\n__ip6_append_data(), tcp_sendmsg_locked()) and call\nskb_zcopy_downgrade_managed() before ESP touches the frag array: it takes\na real reference on each existing frag and clears SKBFL_MANAGED_FRAG_REFS,\nso the per-frag unref in esp_ssg_unref() and the frag release in\nskb_release_data() are both balanced and no mixed-ownership frag array is\nleft behind.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98368","source_modified_at":"2026-10-19T09:18:20.253Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"2359264f377cdbdef2d95868cc8fb572949e48d3","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"69a768c12398cada8528080332c822623fa7064d","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"6508304ac2c8cdafca2f4ab915df8c707893e134","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"6cab554f2c0f28773f712ed3a5479103f42ce844","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"0d0845ee61c5df47cc68bc446501f48f71e8dcc6","status":"affected","versionType":"git"},{"version":"753f1ca4e1e50248a1b760c9774d6d6b354562cc","lessThan":"f89416eb3db151170a6f3c6dfc5239d26cdce4d2","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98368","source_modified_at":"2026-10-19T09:18:20.253Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"6.0","status":"affected"},{"version":"0","lessThan":"6.0","status":"unaffected","versionType":"semver"},{"version":"6.1.189","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.158","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.112","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.54","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.8","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98368","source_modified_at":"2026-10-19T09:18:20.253Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"2359264f377cdbdef2d95868cc8fb572949e48d3","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98368","source_modified_at":"2026-10-19T09:18:20.253Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"69a768c12398cada8528080332c822623fa7064d","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98368","source_modified_at":"2026-10-19T09:18:20.253Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6508304ac2c8cdafca2f4ab915df8c707893e134","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98368","source_modified_at":"2026-10-19T09:18:20.253Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6cab554f2c0f28773f712ed3a5479103f42ce844","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98368","source_modified_at":"2026-10-19T09:18:20.253Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"0d0845ee61c5df47cc68bc446501f48f71e8dcc6","basis":"first unaffected version stated in the CVE record"}],"cvss":7.8,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00126,"percentile":0.02089,"score_date":"2026-10-23"},"published_at":"2026-10-06T08:46:53.292Z","modified_at":"2026-10-19T09:18:20.253Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98368","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:18:20.253Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98368","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/2359264f377cdbdef2d95868cc8fb572949e48d3"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/69a768c12398cada8528080332c822623fa7064d"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/6508304ac2c8cdafca2f4ab915df8c707893e134"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/6cab554f2c0f28773f712ed3a5479103f42ce844"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/0d0845ee61c5df47cc68bc446501f48f71e8dcc6"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/f89416eb3db151170a6f3c6dfc5239d26cdce4d2"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:18:20.253Z","content_hash":"bf7b746df0dc9e63310df9db9522ad8df0195ba06bc57c78fc7fd0fb8938c30e"}}