{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98990", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.384Z", "datePublished": "2026-10-23T12:20:09.349Z", "dateUpdated": "2026-10-23T12:20:09.349Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-23T12:20:09.349Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnamespace: check a submount for references right before unmounting it\n\nshrink_submounts() and mark_mounts_for_expiry() first collect all the\nmounts they are allowed to unmount and then unmount them.\n\nWhether a mount is busy is decided by propagate_mount_busy() on the\ntree. But unmounting the first mount changes the tree that the second\none propagates into. propagate_umount()\nmoves a surviving overmount off a copy it unmounts and mounts it where\nthe copy was mounted. If that's where the propagated copy of the second\nvictim is looked up the overmount becomes a candidate of the second\numount_tree(). It's childless and so trim_one() commits it without\nlooking at its reference count.\n\nSo a synchronous umount pulls out a busy mount that is in use somewhere\nelse and marks it MNT_SYNC_UMOUNT while it has users:\n\n umount2(/tmp/plshrink/p1, 0) = 0 errno 0\n cwd is (unreachable)\n\nThe same two umounts requested one after the other fail with EBUSY.\nThis needs a mount with MNT_SHRINKABLE, i.e., automounted submounts of\nNFS, AFS and CIFS or the tracefs mount below debugfs. Bind mounts\ninherit the flag.\n\nCheck each mount right before it is unmounted under the same hold of\nnamespace_sem and mount_lock as the umount itself. Make sure that the\nalgorithm stays linear." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/namespace.c" ], "versions": [ { "version": "1064f874abc0d05eeed8993815f584d847b72486", "lessThan": "f6394281834492c6516a405a348b545ae698a331", "status": "affected", "versionType": "git" }, { "version": "1064f874abc0d05eeed8993815f584d847b72486", "lessThan": "6e4012e571867868b545c91ca9d6095fdb709907", "status": "affected", "versionType": "git" }, { "version": "1064f874abc0d05eeed8993815f584d847b72486", "lessThan": "d73f04e92c1aab78d96ac6cadb234c8a3a373d22", "status": "affected", "versionType": "git" }, { "version": "1064f874abc0d05eeed8993815f584d847b72486", "lessThan": "18902a23ef36f83d32bafc58ae2484e6bb4bb8ef", "status": "affected", "versionType": "git" }, { "version": "1064f874abc0d05eeed8993815f584d847b72486", "lessThan": "32bf92416614a1e3ff3524fc6b780259c7aad3ef", "status": "affected", "versionType": "git" }, { "version": "5e6ef5ef6eaf690faad3a7c6c665ebf45d7b6ccf", "status": "affected", "versionType": "git" }, { "version": "839d42687dfce0ed0ea2c6bd8d707cc0e276fbe7", "status": "affected", "versionType": "git" }, { "version": "808e83e5add13152bd4a88346487de68395c136b", "status": "affected", "versionType": "git" }, { "version": "6de9d08a9718ee9c12ba6343c50141c2d633e3dc", "status": "affected", "versionType": "git" }, { "version": "4.1.40", "lessThan": "4.2", "status": "affected", "versionType": "semver" }, { "version": "4.4.54", "lessThan": "4.5", "status": "affected", "versionType": "semver" }, { "version": "4.9.15", "lessThan": "4.10", "status": "affected", "versionType": "semver" }, { "version": "4.10.3", "lessThan": "4.11", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/namespace.c" ], "versions": [ { "version": "4.11", "status": "affected" }, { "version": "0", "lessThan": "4.11", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.11", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.12.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "7.2.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "7.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.15" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f6394281834492c6516a405a348b545ae698a331" }, { "url": "https://git.kernel.org/stable/c/6e4012e571867868b545c91ca9d6095fdb709907" }, { "url": "https://git.kernel.org/stable/c/d73f04e92c1aab78d96ac6cadb234c8a3a373d22" }, { "url": "https://git.kernel.org/stable/c/18902a23ef36f83d32bafc58ae2484e6bb4bb8ef" }, { "url": "https://git.kernel.org/stable/c/32bf92416614a1e3ff3524fc6b780259c7aad3ef" } ], "title": "namespace: check a submount for references right before unmounting it", "x_generator": { "engine": "bippy-1.2.0" } } } }