CVE-2025-40287

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A flaw exists in the exFAT file system within the Linux kernel that can lead to a Denial-of-Service (DoS) condition. Malformed dentries in an exFAT filesystem can cause the kernel to hang when specific system calls—SYS openat, SYS ftruncate, and SYS pwrite64—are executed. The root cause is an improper check of dentry.stream.valid size within the exfat find() function, which does not validate for negative values. This allows the aforementioned system calls to succeed and trigger the DoS issue.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.