CVE-2026-45915

In CVE-2026-45915, the Linux kernel FAT filesystem code fixes a parent-link underflow in rmdir. A corrupted FAT image could leave a directory inode with an incorrect i_nlink, causing rmdir to call drop_nlink(dir) and drive i_nlink to 0, triggering a WARN_ON. The patch adds a sanity check in vfat_...