CVE-2023-54119: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54119 is a race condition vulnerability in the Linux kernel's inotify subsystem that can cause invalid watch descriptor (wd) values to be reported to userspace. Specifically, when inotify_freeing_mark() races with inotify_handle_inode_event(), the latter may observe that i_mark->wd has already been reset to -1 and incorrectly report this invalid value to inotify listeners. The vulnerability affects the Linux kernel from version 2.6.31 onward, with fixes backported to stable releases including 5.4.243, 5.10.180, 5.15.112, 6.1.29, 6.2.16, 6.3.3, and 6.4. It was published on December 24, 2025, with a CVSS base score of 0.0 as assessed by ENISA, indicating low direct security severity (Feedly, EUVD).

The root cause is a time-of-check/time-of-use (TOCTOU) race condition (CWE-362) in the Linux kernel's inotify filesystem notification subsystem. When a watch mark is being freed via inotify_freeing_mark(), it resets the watch descriptor (wd) field to -1; if inotify_handle_inode_event() concurrently reads this field before the mark is fully removed, it can propagate the invalid -1 value to userspace applications relying on inotify events. The fix validates that the wd value is sensible before reporting it, and if not, treats the event as if the mark was removed prior to event generation (Feedly). Patches are available across multiple stable kernel branches via commits such as 8fb33166, 2d65c977, 17ad86d8, 145f54ea, fb329499, a48bacee, and c915d8f5 (kernel.org patches).

The primary impact of this vulnerability is incorrect behavior in userspace applications that rely on inotify for filesystem event monitoring — receiving an event with wd = -1 can confuse or crash inotify listeners, potentially causing denial of service or missed filesystem events. There is no evidence of direct confidentiality or integrity compromise, and the vulnerability does not enable privilege escalation or remote code execution. The scope is limited to local processes using inotify on affected kernel versions, with no known lateral movement potential (Feedly).

The Linux kernel maintainers have released patches across all affected stable branches. Users should upgrade to kernel versions 5.4.243, 5.10.180, 5.15.112, 6.1.29, 6.2.16, 6.3.3, or 6.4 (or later), depending on their current branch. Linux distribution vendors (e.g., Debian, Ubuntu, RHEL) are expected to incorporate these fixes into their respective kernel packages; administrators should apply available distribution security updates promptly (Feedly, kernel.org patches).