{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53341","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-06-09T07:44:35.399Z","datePublished":"2026-07-01T13:32:22.873Z","dateUpdated":"2026-07-04T11:51:08.911Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-07-04T11:51:08.911Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()\n\nmay_decode_fh() accesses mount::mnt_ns without holding any locks; that\nmeans the mount can concurrently be unmounted, and the mnt_namespace can\nconcurrently be freed after an RCU grace period.\n\nThis race can happens as follows, assuming that the mount point was\ncreated by open_tree(..., OPEN_TREE_CLONE):\n\nthread 1            thread 2            RCU\n                    __do_sys_open_by_handle_at\n                      do_handle_open\n                        handle_to_path\n                          may_decode_fh\n                            is_mounted\n                              [mount::mnt_ns access]\n                            [mount::mnt_ns access]\n__do_sys_close\n  fput_close_sync\n    __fput\n      dissolve_on_fput\n        umount_tree\n        class_namespace_excl_destructor\n          namespace_unlock\n            free_mnt_ns\n              mnt_ns_tree_remove\n                call_rcu(mnt_ns_release_rcu)\n                                        mnt_ns_release_rcu\n                                          mnt_ns_release\n                                            kfree\n                            [mnt_namespace::user_ns access] **UAF**\n\nFix it by taking rcu_read_lock() around the mount::mnt_ns access, like\nin __prepend_path().\nAdditionally, document the semantics of mount::mnt_ns, and use WRITE_ONCE()\nfor writers that can race with lockless readers.\n\nThis bug is unreachable unless one of the following is set:\n\n - CONFIG_PREEMPTION\n - CONFIG_RCU_STRICT_GRACE_PERIOD\n\nbecause it requires an RCU grace period to happen during a syscall without\nan explicit preemption.\n\nThis doesn't seem to have interesting security impact; worst-case, it could\nleak the result of an integer comparison to userspace (from the level\ncheck in cap_capable()), cause an endless loop, or crash the kernel by\ndereferencing an invalid address."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fhandle.c","fs/mount.h","fs/namespace.c"],"versions":[{"version":"620c266f394932e5decc4b34683a75dfc59dc2f4","lessThan":"15ea8dc42a02259d49dee38a658d40f60fcd75ed","status":"affected","versionType":"git"},{"version":"620c266f394932e5decc4b34683a75dfc59dc2f4","lessThan":"32138633e51e6db59e474765cf93268c92b42888","status":"affected","versionType":"git"},{"version":"620c266f394932e5decc4b34683a75dfc59dc2f4","lessThan":"a8ed2c29fcfdac78db96c9da4e659c8a513f2a94","status":"affected","versionType":"git"},{"version":"620c266f394932e5decc4b34683a75dfc59dc2f4","lessThan":"40ab6644b99685755f740b872c00ef40d9aa870e","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fhandle.c","fs/mount.h","fs/namespace.c"],"versions":[{"version":"6.11","status":"affected"},{"version":"0","lessThan":"6.11","status":"unaffected","versionType":"semver"},{"version":"6.12.95","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.36","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.13","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"6.11","versionEndExcluding":"6.12.95"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.18.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"7.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/15ea8dc42a02259d49dee38a658d40f60fcd75ed"},{"url":"https://git.kernel.org/stable/c/32138633e51e6db59e474765cf93268c92b42888"},{"url":"https://git.kernel.org/stable/c/a8ed2c29fcfdac78db96c9da4e659c8a513f2a94"},{"url":"https://git.kernel.org/stable/c/40ab6644b99685755f740b872c00ef40d9aa870e"}],"title":"fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()","x_generator":{"engine":"bippy-1.2.0"}}}}