{"id":"CVE-2026-72034","revision":"a1f1f439a6f74e38aa1f2b931e8776e1","records":[{"revision":"a1f1f439a6f74e38aa1f2b931e8776e1","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-72034","aliases":[],"title":"fhandle: reject detached mounts in capable_wrt_mount()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfhandle: reject detached mounts in capable_wrt_mount()\n\nThe recent fhandle RCU fix moved the mount namespace capability check\ninto capable_wrt_mount(), so a non-NULL mnt_namespace survives the\nns_capable() dereference. The helper still assumes the later\nREAD_ONCE(mount->mnt_ns) must be non-NULL because may_decode_fh()\nchecked is_mounted() first.\n\nThat assumption is not stable. A detached mount from\nopen_tree(..., OPEN_TREE_CLONE) can be dissolved on fput while\nopen_by_handle_at() is between those checks, and umount_tree() can\nclear mount->mnt_ns. If the helper observes NULL, it dereferences\nmnt_ns->user_ns and panics.\n\nReturn false when the RCU read observes a detached mount. This keeps\nthe relaxed permission path conservative: a mount no longer attached\nto a namespace cannot authorize open_by_handle_at() access.","state":0,"publishedAt":"2026-08-15T05:51:55.739+00:00","modifiedAt":"2026-10-19T21:19:23.84+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/fhandle.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"620c266f394932e5decc4b34683a75dfc59dc2f4\",\n                            \"lessThan\": \"15104234c267ebe04b9f9a73e5c2179cc265ff60\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"620c266f394932e5decc4b34683a75dfc59dc2f4\",\n                            \"lessThan\": \"6c52226072a3c61337b1eec1799bb987748884fa\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"620c266f394932e5decc4b34683a75dfc59dc2f4\",\n                            \"lessThan\": \"6ee183d89261bf1d1cf9f06d80a40dab8f36ee55\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"620c266f394932e5decc4b34683a75dfc59dc2f4\",\n                            \"lessThan\": \"6c732471740bc2ac9b0946134f9f551dc75f4369\",\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/fhandle.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.11\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.11\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\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/15104234c267ebe04b9f9a73e5c2179cc265ff60","https://git.kernel.org/stable/c/6c52226072a3c61337b1eec1799bb987748884fa","https://git.kernel.org/stable/c/6ee183d89261bf1d1cf9f06d80a40dab8f36ee55","https://git.kernel.org/stable/c/6c732471740bc2ac9b0946134f9f551dc75f4369"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72034","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-72034","identifiers":["CVE-2026-72034"]},"retained":false,"historicalAffected":[]}],"coverage":[]}