{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-98539", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-98539", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-10-18T15:18:06.921Z", "updatedAt": "2026-10-19T09:21:22.671Z", "importedAt": "2026-10-24T01:58:41.756Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "fs/ntfs3: use d_instantiate_new() in ntfs_create_inode() and murder syzbot's \"WARNING in do_new_mount\" saga", "summary": "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.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "status": "affected", "versionType": "git", "lessThan": "6fda7121cb6a8ea6fbd77d0f787f04b8e8b5358e" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "status": "affected", "versionType": "git", "lessThan": "37ec7353f4ac495b28284b0fcb0e53d21d1b3f3f" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "status": "affected", "versionType": "git", "lessThan": "1ae2a242c15b03470b1b16289298e597bbe3bb29" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "status": "affected", "versionType": "git", "lessThan": "1abd643f3783ea8f8e273c18697ff0413aa92dc7" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.15" }, { "version": "6.12.112", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.55", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.2.9", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.2.*" }, { "version": "7.3", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }