{"schema":"threatline.record/2","record":{"id":"CVE-2026-99172","aliases":[],"summary":"ipc: drop the mqueue mount with kern_unmount() on setup failure","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipc: drop the mqueue mount with kern_unmount() on setup failure\n\nmq_init_ns() creates the mqueue mount with fc_mount_longterm(), so its\n->mnt_ns is MNT_NS_INTERNAL. When setting up the mqueue or ipc sysctls\nor msg_init_ns() fails afterwards, create_ipc_ns() drops it with a plain\nmntput(). With ->mnt_ns set that takes the fast path of\nmntput_no_expire(). The count drops to zero and nothing ever kills the\nmount, so the mount and the mqueue superblock are leaked.\n\nCommit dc55e35f9e81 (\"ipc: Store mqueue sysctls in the ipc namespace\")\nadded the first failure path after mq_init_ns() and never dropped the\nmount. Commit 7229d74e5e8c (\"ipc: create_ipc_ns: drop mqueue mount on\nsysctl setup failure\") tried to fix that with a mntput() but that\ndoesn't help for a long-term mount.\n\nUse kern_unmount(). free_ipc() open-codes the same thing for a namespace\nthat made it.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99172","source_modified_at":"2026-10-28T10:35:27.245Z","fetched_at":"2026-10-28T15:55:58.673066Z","product":"Linux","vendor":"Linux","versions":[{"version":"dc55e35f9e810f23dd69cfdc91a3d636023f57a2","lessThan":"c0620b648321fff654173d238d4a85298ea16d05","status":"affected","versionType":"git"},{"version":"dc55e35f9e810f23dd69cfdc91a3d636023f57a2","lessThan":"f0e48172a59e517e613b73f73cc35f24fd123aeb","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99172","source_modified_at":"2026-10-28T10:35:27.245Z","fetched_at":"2026-10-28T15:55:58.673066Z","product":"Linux","vendor":"Linux","versions":[{"version":"5.19","status":"affected"},{"version":"0","lessThan":"5.19","status":"unaffected","versionType":"semver"},{"version":"7.2.13","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-28T10:35:27.245Z","modified_at":"2026-10-28T10:35:27.245Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-99172","fetched_at":"2026-10-28T15:55:58.673066Z","source_modified_at":"2026-10-28T10:35:27.245Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/c0620b648321fff654173d238d4a85298ea16d05"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/f0e48172a59e517e613b73f73cc35f24fd123aeb"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-28T10:35:27.245Z","content_hash":"d16129cca84dca54b3a4f021498523382512dcaa48abd7265a7b36a4d3094db9"}}