{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-98368", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.344Z", "datePublished": "2026-10-06T08:46:53.292Z", "dateUpdated": "2026-10-06T08:46:53.292Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-06T08:46:53.292Z"}, "descriptions": [{"lang": "en", "value": "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."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv4/esp4.c", "net/ipv6/esp6.c"], "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"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv4/esp4.c", "net/ipv6/esp6.c"], "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-rc4", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.1.189"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.6.158"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.12.112"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.18.54"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.2.8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.3-rc4"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2359264f377cdbdef2d95868cc8fb572949e48d3"}, {"url": "https://git.kernel.org/stable/c/69a768c12398cada8528080332c822623fa7064d"}, {"url": "https://git.kernel.org/stable/c/6508304ac2c8cdafca2f4ab915df8c707893e134"}, {"url": "https://git.kernel.org/stable/c/6cab554f2c0f28773f712ed3a5479103f42ce844"}, {"url": "https://git.kernel.org/stable/c/0d0845ee61c5df47cc68bc446501f48f71e8dcc6"}, {"url": "https://git.kernel.org/stable/c/f89416eb3db151170a6f3c6dfc5239d26cdce4d2"}], "title": "esp: downgrade zerocopy managed frags before mutating skb frags", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/ipv4/esp4.c", "net/ipv6/esp6.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2359264f377cdbdef2d95868cc8fb572949e48d3", "status": "affected", "version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc", "versionType": "git"}, {"lessThan": "69a768c12398cada8528080332c822623fa7064d", "status": "affected", "version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc", "versionType": "git"}, {"lessThan": "6508304ac2c8cdafca2f4ab915df8c707893e134", "status": "affected", "version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc", "versionType": "git"}, {"lessThan": "6cab554f2c0f28773f712ed3a5479103f42ce844", "status": "affected", "version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc", "versionType": "git"}, {"lessThan": "0d0845ee61c5df47cc68bc446501f48f71e8dcc6", "status": "affected", "version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc", "versionType": "git"}, {"lessThan": "f89416eb3db151170a6f3c6dfc5239d26cdce4d2", "status": "affected", "version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/ipv4/esp4.c", "net/ipv6/esp6.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.0"}, {"lessThan": "6.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.189", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.158", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.112", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.54", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.8", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3-rc4", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-98368", "lastModified": "2026-10-06T09:18:31.130", "metrics": {}, "published": "2026-10-06T09:18:31.130", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0d0845ee61c5df47cc68bc446501f48f71e8dcc6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2359264f377cdbdef2d95868cc8fb572949e48d3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6508304ac2c8cdafca2f4ab915df8c707893e134"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/69a768c12398cada8528080332c822623fa7064d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6cab554f2c0f28773f712ed3a5479103f42ce844"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f89416eb3db151170a6f3c6dfc5239d26cdce4d2"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{}