{"cve":"CVE-2026-23199","nvd":{"published":"2026-02-14T17:15:57.743","modified":"2026-06-17T10:21:05.097","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nprocfs: avoid fetching build ID while holding VMA lock\n\nFix PROCMAP_QUERY to fetch optional build ID only after dropping mmap_lock\nor per-VMA lock, whichever was used to lock VMA under question, to avoid\ndeadlock reported by syzbot:\n\n -> #1 (&mm->mmap_lock){++++}-{4:4}:\n        __might_fault+0xed/0x170\n        _copy_to_iter+0x118/0x1720\n        copy_page_to_iter+0x12d/0x1e0\n        filemap_read+0x720/0x10a0\n        blkdev_read_iter+0x2b5/0x4e0\n        vfs_read+0x7f4/0xae0\n        ksys_read+0x12a/0x250\n        do_syscall_64+0xcb/0xf80\n        entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n -> #0 (&sb->s_type->i_mutex_key#8){++++}-{4:4}:\n        __lock_acquire+0x1509/0x26d0\n        lock_acquire+0x185/0x340\n        down_read+0x98/0x490\n        blkdev_read_iter+0x2a7/0x4e0\n        __kernel_read+0x39a/0xa90\n        freader_fetch+0x1d5/0xa80\n        __build_id_parse.isra.0+0xea/0x6a0\n        do_procmap_query+0xd75/0x1050\n        procfs_procmap_ioctl+0x7a/0xb0\n        __x64_sys_ioctl+0x18e/0x210\n        do_syscall_64+0xcb/0xf80\n        entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n other info that might help us debug this:\n\n  Possible unsafe locking scenario:\n\n        CPU0                    CPU1\n        ----                    ----\n   rlock(&mm->mmap_lock);\n                                lock(&sb->s_type->i_mutex_key#8);\n                                lock(&mm->mmap_lock);\n   rlock(&sb->s_type->i_mutex_key#8);\n\n  *** DEADLOCK ***\n\nThis seems to be exacerbated (as we haven't seen these syzbot reports\nbefore that) by the recent:\n\n\t777a8560fd29 (\"lib/buildid: use __kernel_read() for sleepable context\")\n\nTo make this safe, we need to grab file refcount while VMA is still locked, but\nother than that everything is pretty straightforward. Internal build_id_parse()\nAPI assumes VMA is passed, but it only needs the underlying file reference, so\njust add another variant build_id_parse_file() that expects file passed\ndirectly.\n\n[akpm@linux-foundation.org: fix up kerneldoc]","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/b5cbacd7f86f4f62b8813688c8e73be94e8e1951","https://git.kernel.org/stable/c/b9b97e6aeb534315f9646b2090d1a5024c6a4e82","https://git.kernel.org/stable/c/cbc03ce3e6ce7e21214c3f02218213574c1a2d08"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:23:35.260773158+00:00"},"epss":{"cve":"CVE-2026-23199","score":0.00103,"percentile":0.00971,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}