{"id":"CVE-2026-53198","revision":"a12f728470bc40f3964d8720d9ef8265","records":[{"revision":"a12f728470bc40f3964d8720d9ef8265","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-53198","aliases":[],"title":"ksmbd: fix use-after-free of a deferred file_lock on double SMB2_CANCEL","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free of a deferred file_lock on double SMB2_CANCEL\n\nA deferred byte-range lock (an SMB2_LOCK that blocks) registers an async work on\nconn->async_requests via setup_async_work(), with cancel_fn =\nsmb2_remove_blocked_lock and cancel_argv[0] pointing at the struct file_lock.\n\nWhen the request is cancelled, the worker frees the file_lock with\nlocks_free_lock() and takes the cancelled early-exit, which \"goto out\"s and never\nreaches release_async_work() -- the only site that unlinks the work from\nconn->async_requests and clears cancel_fn/cancel_argv. The work therefore stays\nmatchable on async_requests with a live cancel_fn pointing at the freed file_lock,\nuntil connection teardown finally runs release_async_work().\n\nsmb2_cancel() fires cancel_fn unconditionally with no state guard, so a second\nSMB2_CANCEL for the same AsyncId, arriving in that window, re-runs\nsmb2_remove_blocked_lock() on the freed file_lock -- a slab use-after-free:\n\n  BUG: KASAN: slab-use-after-free in __locks_delete_block\n    __locks_delete_block\n    locks_delete_block\n    ksmbd_vfs_posix_lock_unblock\n    smb2_remove_blocked_lock\n    smb2_cancel                 <- 2nd SMB2_CANCEL fires cancel_fn\n    handle_ksmbd_work\n  Allocated by ...: locks_alloc_lock <- smb2_lock\n  Freed by ...:     locks_free_lock  <- smb2_lock (cancelled branch)\n  ... cache file_lock_cache of size 192\n\nReproduced on mainline with KASAN by an authenticated SMB client.\n\nSkip a work whose state is already KSMBD_WORK_CANCELLED so its cancel callback\ncannot be fired a second time.","state":0,"publishedAt":"2026-06-25T08:39:07.65+00:00","modifiedAt":"2026-10-15T01:22:39.317+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/smb/server/smb2pdu.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n                            \"lessThan\": \"b7063c7426ea5a4d15e01b60538718765392f49d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n                            \"lessThan\": \"0da2e073f9cbf4985a0fd9acb71bc5ff599f8afd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n                            \"lessThan\": \"89ae9df09d2c1fb4a4eb495c113a7ce1dca34147\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n                            \"lessThan\": \"14d2eee0193ac3cd1bf3d014373449f0b8d35d6d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n                            \"lessThan\": \"2b2eda2821cff1d1b5a423b6ee7d8fc6fbc8e694\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n                            \"lessThan\": \"f580d27e8928828693df44ba2db0fffdbe11dfea\",\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/smb/server/smb2pdu.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.15\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.176\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.143\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.94\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.36\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.13\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/b7063c7426ea5a4d15e01b60538718765392f49d","https://git.kernel.org/stable/c/0da2e073f9cbf4985a0fd9acb71bc5ff599f8afd","https://git.kernel.org/stable/c/89ae9df09d2c1fb4a4eb495c113a7ce1dca34147","https://git.kernel.org/stable/c/14d2eee0193ac3cd1bf3d014373449f0b8d35d6d","https://git.kernel.org/stable/c/2b2eda2821cff1d1b5a423b6ee7d8fc6fbc8e694","https://git.kernel.org/stable/c/f580d27e8928828693df44ba2db0fffdbe11dfea"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53198","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53198","identifiers":["CVE-2026-53198"]},"retained":false,"historicalAffected":[]}],"coverage":[]}