{"apiVersion":"1.0","identifier":"CVE-2026-99173","description":"In the Linux kernel, the following vulnerability has been resolved: eventfs: Free the eventfs_inode after an rcu grace period too tracefs_d_revalidate() reads ->is_freed of the eventfs_inode that dentry->d_fsdata points to, and ->d_revalidate() is called in rcu pathwalk mode with nothing but rcu_read_lock() held. The dentry itself stays around for such a walker, but tracefs_d_release() drops its reference to the eventfs_inode when the dentry is killed, and release_ei() then frees it after a grace period of eventfs_srcu. An SRCU grace period doesn-t wait for rcu_read_lock() sections, so the walker can read an eventfs_inode that is already gone. With a pathwalk held up in tracefs_d_revalidate() while the dentry goes away: BUG: KASAN: slab-use-after-free in tracefs_d_revalidate+0x76/0x90 Read of size 1 at addr ff1100010152d8d0 by task walker/97 Call Trace: <TASK> tracefs_d_revalidate+0x76/0x90 lookup_fast+0x320/0x640 path_lookupat+0x160/0xb00 filename_lookup+0x1f1/0x5b0 vfs_statx+0xd7/0x3b0 vfs_fstatat+0x4d/0x90 __do_sys_newfstatat+0xa0/0x100 do_syscall_64+0x10e/0x5e0 entry_SYSCALL_64_after_hwframe+0x77/0x7f [...] Allocated by task 1: __kmalloc_cache_noprof+0x249/0x560 eventfs_create_dir+0x7a/0x590 event_create_dir+0x2fb/0xcf0 trace_add_event_call+0xbf/0x150 [...] Freed by task 11: kfree+0x1db/0x5b0 srcu_invoke_callbacks+0x3a3/0x620 process_one_work+0x937/0x1810 worker_thread+0x4f1/0xd60 Before commit 8e556432477e (-eventfs: Use SRCU for freeing eventfs_inodes-) release_ei() used call_rcu(), which covered the walker, while eventfs_iterate() needs the SRCU grace period. Wait for both and chain call_rcu() from the SRCU callback.","publishedAt":"2026-10-28T11:17:37","lastModifiedAt":"2026-10-31T13:17:58","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-99173","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00125,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-99173","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-99173","en":"https://www.redsauce.net/en/cves/CVE-2026-99173","fr":"https://www.redsauce.net/fr/cves/CVE-2026-99173","pt":"https://www.redsauce.net/pt/cves/CVE-2026-99173","de":"https://www.redsauce.net/de/cves/CVE-2026-99173","sk":"https://www.redsauce.net/sk/cves/CVE-2026-99173","el":"https://www.redsauce.net/el/cves/CVE-2026-99173"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-99173"}}