{"id":"CVE-2026-98995","revision":"da7c152530064471b50e313509aec427","records":[{"revision":"da7c152530064471b50e313509aec427","observedAt":"2026-10-24T16:17:04.479+00:00","statement":{"source":"cve-program","id":"CVE-2026-98995","aliases":[],"title":"namespace: reset the old parent's ->overmount in mnt_change_mountpoint()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnamespace: reset the old parent's ->overmount in mnt_change_mountpoint()\n\n__umount_mnt() resets ->overmount of the parent when it unmounts the\nmount that overmounts it. mnt_change_mountpoint() doesn't. It moves the\nmount to its new parent and leaves the old one pointing at it.\n\nFor a mount that is moved beneath in attach_recursive_mnt() that doesn't\nmatter. The new mount has already reset ->overmount of the old parent by\nthe time the old top mount is moved onto it.\n\nIt matters for reparent() though. propagate_umount() moves a surviving\novermount onto the first ancestor that isn't going to be unmounted. The\nmount it was taken from is unmounted immediately afterwards. If a file\ndescriptor keeps that unmounted mount alive ->overmount points at the\nmoved mount. That's a dangling pointer and UAF as the moved mount is\nunmounted and freed.\n\ndo_lock_mount() follows ->overmount from the target path under\nmount_lock. With a file descriptor on such a mount as the target of a\nmount beneath topmost_overmount() walks into the freed mount and\ndo_lock_mount() takes references on whatever it finds there.\n\nSo reset ->overmount of the old parent in mnt_change_mountpoint() the\nsame way __umount_mnt() does. A mount's ->overmount is then always a\nmount that is attached to it.","state":0,"publishedAt":"2026-10-23T12:20:14.155+00:00","modifiedAt":"2026-10-24T14:09:55.095+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\": \"ffdc52fbbd5835a936ad683c943d6d103a2d4514\",\n                            \"lessThan\": \"5e0a1f2c753a79749bc2ead3ae2f2ede3941daa5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ffdc52fbbd5835a936ad683c943d6d103a2d4514\",\n                            \"lessThan\": \"08d575ee89393fd812dbdca7b5d7b4574cd5a564\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ffdc52fbbd5835a936ad683c943d6d103a2d4514\",\n                            \"lessThan\": \"476ef286a7a5db8bda51325dc0c45887b4d99d9a\",\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\": \"6.17\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.17\",\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":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/5e0a1f2c753a79749bc2ead3ae2f2ede3941daa5","https://git.kernel.org/stable/c/08d575ee89393fd812dbdca7b5d7b4574cd5a564","https://git.kernel.org/stable/c/476ef286a7a5db8bda51325dc0c45887b4d99d9a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98995","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98995","identifiers":["CVE-2026-98995"]},"retained":false,"historicalAffected":[]}],"coverage":[]}