{"api_version":"1","generated_at":"2026-10-20T17:41:28+00:00","cve":"CVE-2026-98539","urls":{"html":"https://cve.report/CVE-2026-98539","api":"https://cve.report/api/cve/CVE-2026-98539.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98539","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98539"},"summary":{"title":"fs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and murder syzbot's \"WARNING in do_new_mount\" saga","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and murder syzbot's \"WARNING in do_new_mount\" saga\n\nntfs_create_inode() creates a new inode via ntfs_new_inode(). It hashes\nit with insert_inode_locked() and so it's marked as I_NEW until\nunlock_new_inode().\n\nntfs 3 calls d_instantiate() in between though... Since the dentry was\nalready hashed by the lookup before the create any path walk finds it\nwithout touching the parent's i_rwsem and so can lock the inode.\n\nIf the inode is a directory unlock_new_inode() calls\nlockdep_annotate_inode_mutex_key() and marks i_rwsem with the\ni_mutex_dir_key class.\n\nThat resets the count and the owner of a lock somebody else may already\nhold by now...\n\nsyzbot has been spamming us with the same godforsaken bug\n\n  \"WARNING in do_new_mount\"\n\nsince 2023. I can't take it anymore so I went looking. Afaict, syzbot's\nexecutor chdirs into a freshly mounted ntfs3 image, creates a\ndirectory and then mounts some pseudofs on it. Everytime the mkdir()\ntakes longer than syzbot waits mount() runs concurrently:\n\n  mkdir(\"./sys\")                        mount(NULL, \"./sys\", \"sysfs\")\n  ntfs_create_inode()\n    d_instantiate()\n                                        user_path_at() finds the dentry\n                                        do_lock_mount()\n                                          inode_lock(inode)\n                                          namespace_lock()\n    unlock_new_inode()\n      lockdep_annotate_inode_mutex_key()\n        init_rwsem(&inode->i_rwsem)\n                                        unlock_mount()\n                                          inode_unlock(inode)\n\nThe mount side then releases a lock that according to the rwsem nobody\nholds:\n\n  DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && ...):\n  count = 0x0, magic = 0xffff888043a854e8, owner = 0x0,\n  curr 0xffff888000244880, list empty\n  WARNING: CPU: 0 PID: 5346 at kernel/locking/rwsem.c:1368 __up_write\n  Call Trace:\n   inode_unlock include/linux/fs.h:877 [inline]\n   unlock_mount fs/namespace.c:2892 [inline]\n   do_new_mount_fc fs/namespace.c:3828 [inline]\n   do_new_mount+0x777/0xa40 fs/namespace.c:3887\n\nOn PREEMPT_RT the same thing shows up as\n\n  DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current)\n  WARNING: kernel/locking/rtmutex_common.h:193 at rt_mutex_slowunlock\n\nThe up_write() underflows the reset count. A following inode_lock() on\nthat directory then never returns. A path walk into the new directory\nracing with the mkdir() corrupts the lock the same way via\ninode_lock_shared() in lookup_slow().\n\nSwitch to d_instantiate_new() and drop the trailing unlock_new_inode().\nAll error paths bail out before that point with I_NEW still set and\nkeep using discard_new_inode().\n\nMay we never see this fscking bug report again.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:17:05","updated_at":"2026-10-18 16:17:05"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/1ae2a242c15b03470b1b16289298e597bbe3bb29","name":"https://git.kernel.org/stable/c/1ae2a242c15b03470b1b16289298e597bbe3bb29","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6fda7121cb6a8ea6fbd77d0f787f04b8e8b5358e","name":"https://git.kernel.org/stable/c/6fda7121cb6a8ea6fbd77d0f787f04b8e8b5358e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1abd643f3783ea8f8e273c18697ff0413aa92dc7","name":"https://git.kernel.org/stable/c/1abd643f3783ea8f8e273c18697ff0413aa92dc7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/37ec7353f4ac495b28284b0fcb0e53d21d1b3f3f","name":"https://git.kernel.org/stable/c/37ec7353f4ac495b28284b0fcb0e53d21d1b3f3f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98539","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98539","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 82cae269cfa953032fbb8980a7d554d60fb00b17 6fda7121cb6a8ea6fbd77d0f787f04b8e8b5358e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 82cae269cfa953032fbb8980a7d554d60fb00b17 37ec7353f4ac495b28284b0fcb0e53d21d1b3f3f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 82cae269cfa953032fbb8980a7d554d60fb00b17 1ae2a242c15b03470b1b16289298e597bbe3bb29 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 82cae269cfa953032fbb8980a7d554d60fb00b17 1abd643f3783ea8f8e273c18697ff0413aa92dc7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.112 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.55 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.9 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/ntfs3/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"6fda7121cb6a8ea6fbd77d0f787f04b8e8b5358e","status":"affected","version":"82cae269cfa953032fbb8980a7d554d60fb00b17","versionType":"git"},{"lessThan":"37ec7353f4ac495b28284b0fcb0e53d21d1b3f3f","status":"affected","version":"82cae269cfa953032fbb8980a7d554d60fb00b17","versionType":"git"},{"lessThan":"1ae2a242c15b03470b1b16289298e597bbe3bb29","status":"affected","version":"82cae269cfa953032fbb8980a7d554d60fb00b17","versionType":"git"},{"lessThan":"1abd643f3783ea8f8e273c18697ff0413aa92dc7","status":"affected","version":"82cae269cfa953032fbb8980a7d554d60fb00b17","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ntfs3/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.15"},{"lessThan":"5.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.112","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.55","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.112","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.55","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.9","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"5.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and murder syzbot's \"WARNING in do_new_mount\" saga\n\nntfs_create_inode() creates a new inode via ntfs_new_inode(). It hashes\nit with insert_inode_locked() and so it's marked as I_NEW until\nunlock_new_inode().\n\nntfs 3 calls d_instantiate() in between though... Since the dentry was\nalready hashed by the lookup before the create any path walk finds it\nwithout touching the parent's i_rwsem and so can lock the inode.\n\nIf the inode is a directory unlock_new_inode() calls\nlockdep_annotate_inode_mutex_key() and marks i_rwsem with the\ni_mutex_dir_key class.\n\nThat resets the count and the owner of a lock somebody else may already\nhold by now...\n\nsyzbot has been spamming us with the same godforsaken bug\n\n  \"WARNING in do_new_mount\"\n\nsince 2023. I can't take it anymore so I went looking. Afaict, syzbot's\nexecutor chdirs into a freshly mounted ntfs3 image, creates a\ndirectory and then mounts some pseudofs on it. Everytime the mkdir()\ntakes longer than syzbot waits mount() runs concurrently:\n\n  mkdir(\"./sys\")                        mount(NULL, \"./sys\", \"sysfs\")\n  ntfs_create_inode()\n    d_instantiate()\n                                        user_path_at() finds the dentry\n                                        do_lock_mount()\n                                          inode_lock(inode)\n                                          namespace_lock()\n    unlock_new_inode()\n      lockdep_annotate_inode_mutex_key()\n        init_rwsem(&inode->i_rwsem)\n                                        unlock_mount()\n                                          inode_unlock(inode)\n\nThe mount side then releases a lock that according to the rwsem nobody\nholds:\n\n  DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && ...):\n  count = 0x0, magic = 0xffff888043a854e8, owner = 0x0,\n  curr 0xffff888000244880, list empty\n  WARNING: CPU: 0 PID: 5346 at kernel/locking/rwsem.c:1368 __up_write\n  Call Trace:\n   inode_unlock include/linux/fs.h:877 [inline]\n   unlock_mount fs/namespace.c:2892 [inline]\n   do_new_mount_fc fs/namespace.c:3828 [inline]\n   do_new_mount+0x777/0xa40 fs/namespace.c:3887\n\nOn PREEMPT_RT the same thing shows up as\n\n  DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current)\n  WARNING: kernel/locking/rtmutex_common.h:193 at rt_mutex_slowunlock\n\nThe up_write() underflows the reset count. A following inode_lock() on\nthat directory then never returns. A path walk into the new directory\nracing with the mkdir() corrupts the lock the same way via\ninode_lock_shared() in lookup_slow().\n\nSwitch to d_instantiate_new() and drop the trailing unlock_new_inode().\nAll error paths bail out before that point with I_NEW still set and\nkeep using discard_new_inode().\n\nMay we never see this fscking bug report again."}],"providerMetadata":{"dateUpdated":"2026-10-19T09:21:22.671Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/6fda7121cb6a8ea6fbd77d0f787f04b8e8b5358e"},{"url":"https://git.kernel.org/stable/c/37ec7353f4ac495b28284b0fcb0e53d21d1b3f3f"},{"url":"https://git.kernel.org/stable/c/1ae2a242c15b03470b1b16289298e597bbe3bb29"},{"url":"https://git.kernel.org/stable/c/1abd643f3783ea8f8e273c18697ff0413aa92dc7"}],"title":"fs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and murder syzbot's \"WARNING in do_new_mount\" saga","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98539","datePublished":"2026-10-18T15:18:06.921Z","dateReserved":"2026-09-25T10:25:14.356Z","dateUpdated":"2026-10-19T09:21:22.671Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:17:05","lastModifiedDate":"2026-10-18 16:17:05","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98539","Ordinal":"1","Title":"fs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and mur","CVE":"CVE-2026-98539","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98539","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and murder syzbot's \"WARNING in do_new_mount\" saga\n\nntfs_create_inode() creates a new inode via ntfs_new_inode(). It hashes\nit with insert_inode_locked() and so it's marked as I_NEW until\nunlock_new_inode().\n\nntfs 3 calls d_instantiate() in between though... Since the dentry was\nalready hashed by the lookup before the create any path walk finds it\nwithout touching the parent's i_rwsem and so can lock the inode.\n\nIf the inode is a directory unlock_new_inode() calls\nlockdep_annotate_inode_mutex_key() and marks i_rwsem with the\ni_mutex_dir_key class.\n\nThat resets the count and the owner of a lock somebody else may already\nhold by now...\n\nsyzbot has been spamming us with the same godforsaken bug\n\n  \"WARNING in do_new_mount\"\n\nsince 2023. I can't take it anymore so I went looking. Afaict, syzbot's\nexecutor chdirs into a freshly mounted ntfs3 image, creates a\ndirectory and then mounts some pseudofs on it. Everytime the mkdir()\ntakes longer than syzbot waits mount() runs concurrently:\n\n  mkdir(\"./sys\")                        mount(NULL, \"./sys\", \"sysfs\")\n  ntfs_create_inode()\n    d_instantiate()\n                                        user_path_at() finds the dentry\n                                        do_lock_mount()\n                                          inode_lock(inode)\n                                          namespace_lock()\n    unlock_new_inode()\n      lockdep_annotate_inode_mutex_key()\n        init_rwsem(&inode->i_rwsem)\n                                        unlock_mount()\n                                          inode_unlock(inode)\n\nThe mount side then releases a lock that according to the rwsem nobody\nholds:\n\n  DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && ...):\n  count = 0x0, magic = 0xffff888043a854e8, owner = 0x0,\n  curr 0xffff888000244880, list empty\n  WARNING: CPU: 0 PID: 5346 at kernel/locking/rwsem.c:1368 __up_write\n  Call Trace:\n   inode_unlock include/linux/fs.h:877 [inline]\n   unlock_mount fs/namespace.c:2892 [inline]\n   do_new_mount_fc fs/namespace.c:3828 [inline]\n   do_new_mount+0x777/0xa40 fs/namespace.c:3887\n\nOn PREEMPT_RT the same thing shows up as\n\n  DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current)\n  WARNING: kernel/locking/rtmutex_common.h:193 at rt_mutex_slowunlock\n\nThe up_write() underflows the reset count. A following inode_lock() on\nthat directory then never returns. A path walk into the new directory\nracing with the mkdir() corrupts the lock the same way via\ninode_lock_shared() in lookup_slow().\n\nSwitch to d_instantiate_new() and drop the trailing unlock_new_inode().\nAll error paths bail out before that point with I_NEW still set and\nkeep using discard_new_inode().\n\nMay we never see this fscking bug report again.","Type":"Description","Title":"fs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and mur"}]}}}