{"id":"CVE-2026-98368","revision":"0dfe7e9608bb44f2a691fa0754f0ce71","records":[{"revision":"0dfe7e9608bb44f2a691fa0754f0ce71","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98368","aliases":[],"title":"esp: downgrade zerocopy managed frags before mutating skb frags","description":"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.","state":0,"publishedAt":"2026-10-06T08:46:53.292+00:00","modifiedAt":"2026-10-19T09:18:20.253+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv4/esp4.c\",\n                        \"net/ipv6/esp6.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"753f1ca4e1e50248a1b760c9774d6d6b354562cc\",\n                            \"lessThan\": \"2359264f377cdbdef2d95868cc8fb572949e48d3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"753f1ca4e1e50248a1b760c9774d6d6b354562cc\",\n                            \"lessThan\": \"69a768c12398cada8528080332c822623fa7064d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"753f1ca4e1e50248a1b760c9774d6d6b354562cc\",\n                            \"lessThan\": \"6508304ac2c8cdafca2f4ab915df8c707893e134\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"753f1ca4e1e50248a1b760c9774d6d6b354562cc\",\n                            \"lessThan\": \"6cab554f2c0f28773f712ed3a5479103f42ce844\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"753f1ca4e1e50248a1b760c9774d6d6b354562cc\",\n                            \"lessThan\": \"0d0845ee61c5df47cc68bc446501f48f71e8dcc6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"753f1ca4e1e50248a1b760c9774d6d6b354562cc\",\n                            \"lessThan\": \"f89416eb3db151170a6f3c6dfc5239d26cdce4d2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv4/esp4.c\",\n                        \"net/ipv6/esp6.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.189\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.112\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.54\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.8\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/2359264f377cdbdef2d95868cc8fb572949e48d3","https://git.kernel.org/stable/c/69a768c12398cada8528080332c822623fa7064d","https://git.kernel.org/stable/c/6508304ac2c8cdafca2f4ab915df8c707893e134","https://git.kernel.org/stable/c/6cab554f2c0f28773f712ed3a5479103f42ce844","https://git.kernel.org/stable/c/0d0845ee61c5df47cc68bc446501f48f71e8dcc6","https://git.kernel.org/stable/c/f89416eb3db151170a6f3c6dfc5239d26cdce4d2"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98368","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98368","identifiers":["CVE-2026-98368"]},"retained":false,"historicalAffected":[]}],"coverage":[]}