{"schema":"threatline.record/2","record":{"id":"CVE-2026-98366","aliases":[],"summary":"RDMA/rxe: validate access flags before swapping the MR's PD","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: validate access flags before swapping the MR's PD\n\nrxe_rereg_user_mr() reassigns mr->ibmr.pd first and only then\nvalidates the IB_MR_REREG_ACCESS argument:\n\n\tif (flags & IB_MR_REREG_PD) {\n\t\trxe_put(old_pd);\n\t\trxe_get(pd);\n\t\tmr->ibmr.pd = ibpd;\n\t}\n\n\tif (flags & IB_MR_REREG_ACCESS) {\n\t\tif (access & ~RXE_ACCESS_SUPPORTED_MR)\n\t\t\treturn ERR_PTR(-EOPNOTSUPP);\n\t\tmr->access = access;\n\t}\n\nBoth flags pass the entry check because RXE_MR_REREG_SUPPORTED is\nIB_MR_REREG_PD | IB_MR_REREG_ACCESS, so a caller can reach the access\ncheck with mr->ibmr.pd already reassigned.\n\nmr->ibmr.pd is owned by the core, which adjusts pd->usecnt only on the\nsuccess path: ib_uverbs_rereg_mr() jumps to put_new_uobj on a driver error\nwithout undoing the reassignment, so mr->pd == new_pd while the usecnts\nstill charge the MR to orig_pd. ib_dereg_mr_user() then decrements\nnew_pd, whose count can reach zero while a memory window still references\nit; uverbs_free_pd() frees the PD on that count alone and rxe_mw_cleanup()\nwrites to freed memory:\n\n  BUG: KASAN: slab-use-after-free in __rxe_put+0x31/0xa0\n  Write of size 4 at addr ffff8881301dd690 by task rxe_poc/591\n   __rxe_put+0x31/0xa0\n   rxe_mw_cleanup+0x42/0x200\n   __rxe_cleanup+0x115/0x370\n   rxe_dealloc_mw+0x4c/0x80\n  Allocated by task 591:\n   ib_uverbs_alloc_pd+0x258/0x540\n  Freed by task 591:\n   ib_dealloc_pd_user+0x174/0x210\n   uverbs_free_pd+0x8d/0xc0\n   ib_uverbs_dealloc_pd+0x18e/0x1d0\n\nValidate the access flags before mutating any state so the callback either\napplies every requested change or none.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98366","source_modified_at":"2026-10-19T09:18:18.297Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c","lessThan":"08f12745cb72981aa2cabe214af0c7a42a856f0a","status":"affected","versionType":"git"},{"version":"544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c","lessThan":"7230cc456d4bb2221c20c5f1d22b38b8576aa16f","status":"affected","versionType":"git"},{"version":"544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c","lessThan":"fe602c91a52e161ace4afd5bdb8f33270c554c6f","status":"affected","versionType":"git"},{"version":"544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c","lessThan":"4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8","status":"affected","versionType":"git"},{"version":"544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c","lessThan":"ae36a5b609ae79f4de966328b78d2584be9719a4","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98366","source_modified_at":"2026-10-19T09:18:18.297Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"6.5","status":"affected"},{"version":"0","lessThan":"6.5","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-2026-98366","source_modified_at":"2026-10-19T09:18:18.297Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"08f12745cb72981aa2cabe214af0c7a42a856f0a","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98366","source_modified_at":"2026-10-19T09:18:18.297Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"7230cc456d4bb2221c20c5f1d22b38b8576aa16f","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98366","source_modified_at":"2026-10-19T09:18:18.297Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8","basis":"first unaffected version stated in the CVE record"}],"cvss":7.8,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00116,"percentile":0.01548,"score_date":"2026-10-23"},"published_at":"2026-10-06T08:46:51.638Z","modified_at":"2026-10-19T09:18:18.297Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98366","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:18:18.297Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98366","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/08f12745cb72981aa2cabe214af0c7a42a856f0a"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/7230cc456d4bb2221c20c5f1d22b38b8576aa16f"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/fe602c91a52e161ace4afd5bdb8f33270c554c6f"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/ae36a5b609ae79f4de966328b78d2584be9719a4"}],"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":"2026-10-19T09:18:18.297Z","content_hash":"101ed687209abf708ecae5387c59057f2b8c08c7e8e67930f2bd35799d0b6f27"}}