{"id":"CVE-2026-98986","revision":"b946a6e8d719457a82e956327e343d29","records":[{"revision":"b946a6e8d719457a82e956327e343d29","observedAt":"2026-10-23T16:01:20.601+00:00","statement":{"source":"cve-program","id":"CVE-2026-98986","aliases":[],"title":"namespace: remove the fsnotify marks of a mount namespace in process context","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnamespace: remove the fsnotify marks of a mount namespace in process context\n\nmnt_ns_release() drops the last passive reference of a mount namespace\nand removes its fanotify marks via fsnotify_mntns_delete(). That takes\nthe mutex of every group with a mark on the namespace and the spinlock\nof the connector. Fine from process context. But mnt_ns_tree_remove()\nhands the reference the namespace was allocated with to call_rcu() and\nso the marks are removed from the RCU softirq:\n\n  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:623\n  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/3\n   __mutex_lock+0x113/0x24b0\n   fsnotify_destroy_marks+0x11b/0x3d0\n   mnt_ns_release_rcu+0x57/0xa0\n   rcu_core+0x6b6/0x1e40\n\nand lockdep complains about the connector lock being taken from softirq\ncontext. A fanotify group with a FAN_MARK_MNTNS mark on the mount\nnamespace of another task is all that's needed. Root in a user\nnamespace can do that for a mount namespace it owns. The task exits and\nthe namespace is freed with the mark still on it.\n\nRemove the marks in free_mnt_ns() before the namespace is handed to RCU.\nThat runs in process context once the last active reference is gone. A\nmark is added through a file descriptor to the namespace which holds an\nactive reference so no mark can show up after that.","state":0,"publishedAt":"2026-10-23T12:20:04.966+00:00","modifiedAt":"2026-10-23T12:20:04.966+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                        \"fs/namespace.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"bf630c40164162ba1d3933c2f5e3397d083e0948\",\n                            \"lessThan\": \"888363d74c3b5d32e2accf217add70f8b38e0e2b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bf630c40164162ba1d3933c2f5e3397d083e0948\",\n                            \"lessThan\": \"9e820a6becdd955a04adbedfd767253a47eedd9e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bf630c40164162ba1d3933c2f5e3397d083e0948\",\n                            \"lessThan\": \"1a116222acdcc1bc1a8350727ae6f28907d44594\",\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                        \"fs/namespace.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.15\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.57\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.11\",\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":[],"references":["https://git.kernel.org/stable/c/888363d74c3b5d32e2accf217add70f8b38e0e2b","https://git.kernel.org/stable/c/9e820a6becdd955a04adbedfd767253a47eedd9e","https://git.kernel.org/stable/c/1a116222acdcc1bc1a8350727ae6f28907d44594"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98986","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98986","identifiers":["CVE-2026-98986"]},"retained":false,"historicalAffected":[]}],"coverage":[]}