{"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":"2026-10-30T12:40:44.542Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-30T12:40:44.542Z"},"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":"cda0c4e502a0f74a191471ce100fb061e5ab35d6","status":"affected","versionType":"git"},{"version":"1064f874abc0d05eeed8993815f584d847b72486","lessThan":"3f55f71291e4332983cd63b288d1f2be3c9c08fc","status":"affected","versionType":"git"},{"version":"1064f874abc0d05eeed8993815f584d847b72486","lessThan":"361f59e7f3f9a219fb5567bf9abc8482a154a399","status":"affected","versionType":"git"},{"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":"5.10.273","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.224","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.191","lessThanOrEqual":"6.1.*","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":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.1.191"},{"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/cda0c4e502a0f74a191471ce100fb061e5ab35d6"},{"url":"https://git.kernel.org/stable/c/3f55f71291e4332983cd63b288d1f2be3c9c08fc"},{"url":"https://git.kernel.org/stable/c/361f59e7f3f9a219fb5567bf9abc8482a154a399"},{"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"}}}}