CVE-2026-45915

Summary

In the Linux kernel, the following vulnerability has been resolved:

fat: avoid parent link count underflow in rmdir

Corrupted FAT images can leave a directory inode with an incorrect i_nlink (e.g. 2 even though subdirectories exist). rmdir then unconditionally calls drop_nlink(dir) and can drive i_nlink to 0, triggering the WARN_ON in drop_nlink().

Add a sanity check in vfat_rmdir() and msdos_rmdir(): only drop the parent link count when it is at least 3, otherwise report a filesystem error.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux9a53c3a783c2fa9b969628e65695c11c3e51e673 < 7fe0de287e931e07cb96ecf1f449b2ebdb0e1115affected
LinuxLinux9a53c3a783c2fa9b969628e65695c11c3e51e673 < 9894c79fd9466612d0514be157b5c30cd93aa645affected
LinuxLinux9a53c3a783c2fa9b969628e65695c11c3e51e673 < cd569b87378b9c33ae13c23d6bb9d205d66f7c4baffected
LinuxLinux9a53c3a783c2fa9b969628e65695c11c3e51e673 < d3b7ffa90f613938128432c7b2f35b7aa4bdd86baffected
LinuxLinux9a53c3a783c2fa9b969628e65695c11c3e51e673 < 955c5d670b5ae07c78f4345e23a895638db96ce1affected
LinuxLinux9a53c3a783c2fa9b969628e65695c11c3e51e673 < 17866f8a0822d414cb02e621cf003a7d04396ef8affected
LinuxLinux9a53c3a783c2fa9b969628e65695c11c3e51e673 < d0bb592fa9def2bace90ac8926c0a1d6fa8c1aa0affected
LinuxLinux9a53c3a783c2fa9b969628e65695c11c3e51e673 < 8cafcb881364af5ef3a8b9fed4db254054033d8aaffected
LinuxLinux2.6.19affected
LinuxLinux0 < 2.6.19unaffected
LinuxLinux5.10.252 <= 5.10.*unaffected
LinuxLinux5.15.202 <= 5.15.*unaffected
LinuxLinux6.1.165 <= 6.1.*unaffected
LinuxLinux6.6.128 <= 6.6.*unaffected
LinuxLinux6.12.75 <= 6.12.*unaffected
LinuxLinux6.18.14 <= 6.18.*unaffected
LinuxLinux6.19.4 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References