{"schema":"threatline.record/2","record":{"id":"CVE-2026-98360","aliases":[],"summary":"RDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds\n\nrxe_get_mcg() publishes a newly allocated multicast group in\nrxe->mcg_tree before programming the backing Ethernet multicast address\nwith rxe_mcast_add(), which runs outside mcg_lock. A local userspace\nRDMA client reaches this path with ATTACH_MCAST on a UD QP; if\nrxe_mcast_add() then returns an error (for example -ENODEV when the\nbacking netdev has been removed, or a propagated dev_mc_add() error),\nthe unwind frees the published group without removing it from the tree.\nA later lookup of the same MGID dereferences the freed struct rxe_mcg\nfrom __rxe_lookup_mcg().\n\nFix this by keeping the new mcg private until rxe_mcast_add() succeeds.\nSplit the tree publication into __rxe_publish_mcg(), call rxe_mcast_add()\nbefore taking the tree reference, and free the still-private mcg on\nfailure. Because the group is never visible in mcg_tree until the\nmulticast address is programmed, no concurrent caller can look it up or\nattach a QP to a group that is about to be torn down, so the error path\nneeds no conditional unwind. If another caller publishes the same MGID\nwhile the address is being programmed, the post-add re-check under\nmcg_lock finds the winner; this caller then drops its private object and\nbalances its own rxe_mcast_add() with rxe_mcast_del() before returning\nthe winner.\n\nReproduced by forcing the rxe_mcast_add() error return under KASAN:\nwithout the change the next attach to the same MGID reports a\nslab-use-after-free in __rxe_lookup_mcg(); with it the forced failure\nreturns cleanly. A no-injection attach/detach regression, including a\ntwo-QP shared join/leave and re-attach, stays KASAN- and leak-clean.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98360","source_modified_at":"2026-10-19T09:18:11.284Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"a926a903b7dc39a8a949150258c09290998dd812","lessThan":"ddb43ac0926d4a931bc9b7744b93627f627457e5","status":"affected","versionType":"git"},{"version":"a926a903b7dc39a8a949150258c09290998dd812","lessThan":"c79a789aa15180a1543b5db49c343d12e3ec214d","status":"affected","versionType":"git"},{"version":"a926a903b7dc39a8a949150258c09290998dd812","lessThan":"faae1fb4ccf8205806a8802c008798dabeb0205b","status":"affected","versionType":"git"},{"version":"a926a903b7dc39a8a949150258c09290998dd812","lessThan":"02c0a2fa69c16248a7432af8a6d64ab2a73a5283","status":"affected","versionType":"git"},{"version":"a926a903b7dc39a8a949150258c09290998dd812","lessThan":"d4fc4e37f8a143b0fe83b42c8fb48cf542154fee","status":"affected","versionType":"git"},{"version":"a926a903b7dc39a8a949150258c09290998dd812","lessThan":"1caceeb2d74bbe88223aea55eb8626b4c5f076fd","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98360","source_modified_at":"2026-10-19T09:18:11.284Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"5.18","status":"affected"},{"version":"0","lessThan":"5.18","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-2026-98360","source_modified_at":"2026-10-19T09:18:11.284Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"02c0a2fa69c16248a7432af8a6d64ab2a73a5283","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98360","source_modified_at":"2026-10-19T09:18:11.284Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"1caceeb2d74bbe88223aea55eb8626b4c5f076fd","basis":"first unaffected version stated in the CVE record"}],"cvss":7,"severity":"High","kev":{"listed":false},"epss":{"probability":0.0013,"percentile":0.02398,"score_date":"2026-10-23"},"published_at":"2026-10-06T08:46:46.743Z","modified_at":"2026-10-19T09:18:11.284Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98360","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:18:11.284Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98360","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/ddb43ac0926d4a931bc9b7744b93627f627457e5"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/c79a789aa15180a1543b5db49c343d12e3ec214d"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/faae1fb4ccf8205806a8802c008798dabeb0205b"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/02c0a2fa69c16248a7432af8a6d64ab2a73a5283"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/d4fc4e37f8a143b0fe83b42c8fb48cf542154fee"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/1caceeb2d74bbe88223aea55eb8626b4c5f076fd"}],"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":"2026-10-19T09:18:11.284Z","content_hash":"d0b0ca2899d1d79aa83756221236013345ef25db5045727876c35babdec6bd4b"}}