{"api_version":"1","generated_at":"2026-10-01T19:48:53+00:00","cve":"CVE-2026-89950","urls":{"html":"https://cve.report/CVE-2026-89950","api":"https://cve.report/api/cve/CVE-2026-89950.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89950","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89950"},"summary":{"title":"batman-adv: mcast: linearize skbuff for packet generation","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: mcast: linearize skbuff for packet generation\n\nbatadv_mcast_forw_packet() and batadv_mcast_forw_scrape() is not only\ncalled (indirectly) by the unsharing+linearizing batadv_recv_mcast_packet()\nhandler. When it is called (indirectly) by batadv_mcast_forw_mcsend() then\nit will be unshared but not linearized. The SKB_LINEAR_ASSERT() can\ntherefore cause a fatal BUG().\n\nThe linearization should happen during the expansion of the head because\nthe scrape function can be hit already during the initial\nbatadv_mcast_forw_mode() selection code:\n\n* batadv_interface_tx\n* batadv_mcast_forw_mode\n* batadv_mcast_forw_mode_by_count()\n* batadv_mcast_forw_push()\n  -> calls batadv_mcast_forw_expand_head() before everything else\n* batadv_mcast_forw_push_tvlvs()\n* batadv_mcast_forw_push_dests()\n* batadv_mcast_forw_push_adjust_padding()\n* batadv_mcast_forw_scrape()","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-16 11:17:05","updated_at":"2026-09-16 11:17:05"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/6a30a59e2660afd03c975f1b8eae6a2301161197","name":"https://git.kernel.org/stable/c/6a30a59e2660afd03c975f1b8eae6a2301161197","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c32e5e25c41201c8c3b796a4ab2c45103187091e","name":"https://git.kernel.org/stable/c/c32e5e25c41201c8c3b796a4ab2c45103187091e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e","name":"https://git.kernel.org/stable/c/a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2879177539e3ece483a8e5406970373698e9a6c5","name":"https://git.kernel.org/stable/c/2879177539e3ece483a8e5406970373698e9a6c5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89950","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89950","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 90039133221e33964ccb4a536dad7eb0a372fff7 a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 90039133221e33964ccb4a536dad7eb0a372fff7 c32e5e25c41201c8c3b796a4ab2c45103187091e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 90039133221e33964ccb4a536dad7eb0a372fff7 2879177539e3ece483a8e5406970373698e9a6c5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 90039133221e33964ccb4a536dad7eb0a372fff7 6a30a59e2660afd03c975f1b8eae6a2301161197 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.8","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.8 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 6.18.51 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.5 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/batman-adv/multicast_forw.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e","status":"affected","version":"90039133221e33964ccb4a536dad7eb0a372fff7","versionType":"git"},{"lessThan":"c32e5e25c41201c8c3b796a4ab2c45103187091e","status":"affected","version":"90039133221e33964ccb4a536dad7eb0a372fff7","versionType":"git"},{"lessThan":"2879177539e3ece483a8e5406970373698e9a6c5","status":"affected","version":"90039133221e33964ccb4a536dad7eb0a372fff7","versionType":"git"},{"lessThan":"6a30a59e2660afd03c975f1b8eae6a2301161197","status":"affected","version":"90039133221e33964ccb4a536dad7eb0a372fff7","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/batman-adv/multicast_forw.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.8"},{"lessThan":"6.8","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.110","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.51","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.5","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":"6.12.110","versionStartIncluding":"6.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.51","versionStartIncluding":"6.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.5","versionStartIncluding":"6.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.8","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: mcast: linearize skbuff for packet generation\n\nbatadv_mcast_forw_packet() and batadv_mcast_forw_scrape() is not only\ncalled (indirectly) by the unsharing+linearizing batadv_recv_mcast_packet()\nhandler. When it is called (indirectly) by batadv_mcast_forw_mcsend() then\nit will be unshared but not linearized. The SKB_LINEAR_ASSERT() can\ntherefore cause a fatal BUG().\n\nThe linearization should happen during the expansion of the head because\nthe scrape function can be hit already during the initial\nbatadv_mcast_forw_mode() selection code:\n\n* batadv_interface_tx\n* batadv_mcast_forw_mode\n* batadv_mcast_forw_mode_by_count()\n* batadv_mcast_forw_push()\n  -> calls batadv_mcast_forw_expand_head() before everything else\n* batadv_mcast_forw_push_tvlvs()\n* batadv_mcast_forw_push_dests()\n* batadv_mcast_forw_push_adjust_padding()\n* batadv_mcast_forw_scrape()"}],"providerMetadata":{"dateUpdated":"2026-09-16T10:32:35.485Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/a9603e0a7cb5e0cddc6b23af153cf7daafc5c55e"},{"url":"https://git.kernel.org/stable/c/c32e5e25c41201c8c3b796a4ab2c45103187091e"},{"url":"https://git.kernel.org/stable/c/2879177539e3ece483a8e5406970373698e9a6c5"},{"url":"https://git.kernel.org/stable/c/6a30a59e2660afd03c975f1b8eae6a2301161197"}],"title":"batman-adv: mcast: linearize skbuff for packet generation","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89950","datePublished":"2026-09-16T10:32:35.485Z","dateReserved":"2026-09-11T19:38:34.777Z","dateUpdated":"2026-09-16T10:32:35.485Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 11:17:05","lastModifiedDate":"2026-09-16 11:17:05","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89950","Ordinal":"1","Title":"batman-adv: mcast: linearize skbuff for packet generation","CVE":"CVE-2026-89950","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89950","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: mcast: linearize skbuff for packet generation\n\nbatadv_mcast_forw_packet() and batadv_mcast_forw_scrape() is not only\ncalled (indirectly) by the unsharing+linearizing batadv_recv_mcast_packet()\nhandler. When it is called (indirectly) by batadv_mcast_forw_mcsend() then\nit will be unshared but not linearized. The SKB_LINEAR_ASSERT() can\ntherefore cause a fatal BUG().\n\nThe linearization should happen during the expansion of the head because\nthe scrape function can be hit already during the initial\nbatadv_mcast_forw_mode() selection code:\n\n* batadv_interface_tx\n* batadv_mcast_forw_mode\n* batadv_mcast_forw_mode_by_count()\n* batadv_mcast_forw_push()\n  -> calls batadv_mcast_forw_expand_head() before everything else\n* batadv_mcast_forw_push_tvlvs()\n* batadv_mcast_forw_push_dests()\n* batadv_mcast_forw_push_adjust_padding()\n* batadv_mcast_forw_scrape()","Type":"Description","Title":"batman-adv: mcast: linearize skbuff for packet generation"}]}}}