CVE-2023-54099

A race condition was found in the Linux kernel's filesystem remount code. When remounting a filesystem from read-only to read-write, the SB_RDONLY flag is cleared before the filesystem is fully prepared to accept writes. This allows userspace writes to race with filesystem initialization operations like quota file preparation, potentially causing filesystem corruption or crashes.

This flaw was discovered by syzbot and affects filesystems like ext4 that perform internal writes during remount read-write. The race window exists between clearing SB_RDONLY and completing filesystem-specific initialization. Exploiting this requires timing userspace writes precisely during remount operations.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.