{"id":"CVE-2026-99171","revision":"f654c90e54774424b3503266038bdaf1","records":[{"revision":"f654c90e54774424b3503266038bdaf1","observedAt":"2026-10-28T11:27:43.363+00:00","statement":{"source":"cve-program","id":"CVE-2026-99171","aliases":[],"title":"ntfs3: free the sbi after a grace period","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: free the sbi after a grace period\n\nIf the \"nocase\" mount option ntfs3 uses custom hash and dentry compare\nfunctions. Both access ntfs3 superblock private information in rcu\npathwalk. ntfs_put_super() and ntfs3_kill_sb() drop the info without any\nrcu delay. A lookup that's still inside the filesystem when the last\nreference to the mount is dropped causes a UAF. With a pathwalk held up\nin ntfs_d_hash() while the last reference to the mount goes away:\n\n  BUG: KASAN: slab-use-after-free in ntfs_nls_to_utf16+0x752/0x940\n  Read of size 8 at addr ff1100010453c850 by task walker/99\n  Call Trace:\n   <TASK>\n   ntfs_nls_to_utf16+0x752/0x940\n   ntfs_d_hash+0x22b/0x500\n   link_path_walk+0x11ad/0x1d30\n   path_lookupat+0x63/0xb00\n   filename_lookup+0x1f1/0x5b0\n   vfs_statx+0xd7/0x3b0\n  [...]\n  Allocated by task 95:\n   __kmalloc_cache_noprof+0x249/0x560\n   ntfs_init_fs_context+0x2db/0x5a0\n   alloc_fs_context+0x52e/0xc70\n  [...]\n  Freed by task 98:\n   kfree+0x1db/0x5b0\n   deactivate_locked_super+0x9c/0xf0\n   cleanup_mnt+0x9f/0x130\n   task_work_run+0x131/0x250\n\nThe bug is currently masked by the grace period in namespace_unlock()\nfor umount(2). Keep the necessary information until the filesystem\nprivate info is freed and free it with an rcu delay.\n\nntfs3_free_sbi() now runs from an rcu callback and drops the upcase\ntable via ntfs_put_shared(). So switch s_shared_lock over to\nspin_lock_bh(). Otherwise the callback can deadlock against a task\nholding the lock on the same cpu.","state":0,"publishedAt":"2026-10-28T10:35:26.598+00:00","modifiedAt":"2026-10-28T10:35:26.598+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/ntfs3/ntfs_fs.h\",\n                        \"fs/ntfs3/super.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"a3a956c78efaa202b1d75190136671cf6e87bfbe\",\n                            \"lessThan\": \"c8b1a4840467930e01f1a9374d991d7a8a2896c1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a3a956c78efaa202b1d75190136671cf6e87bfbe\",\n                            \"lessThan\": \"7abecef26a9be8f9de70659a3092250461a52072\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a3a956c78efaa202b1d75190136671cf6e87bfbe\",\n                            \"lessThan\": \"c01b091b06412d3b1b53d8c2925f6de586c8a2fc\",\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/ntfs3/ntfs_fs.h\",\n                        \"fs/ntfs3/super.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.2\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.2\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.59\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.13\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/c8b1a4840467930e01f1a9374d991d7a8a2896c1","https://git.kernel.org/stable/c/7abecef26a9be8f9de70659a3092250461a52072","https://git.kernel.org/stable/c/c01b091b06412d3b1b53d8c2925f6de586c8a2fc"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99171","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-99171","identifiers":["CVE-2026-99171"]},"retained":false,"historicalAffected":[]}],"coverage":[]}