CVE-2026-93800

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

Description An issue exists in the Btrfs file system where a failure in the insert dirty subvol() function, caused by an error returned by btrfs update reloc root(), leads to a use-after-free or double free condition. When the error occurs, the reloc root field of a root remains pointing to a reloc root that has already been freed instead of being set to NULL. This occurs because the root is not added to the rc->dirty subvol roots list, causing it to be skipped during the cleanup process in clean dirty subvols(). Consequently, when the file system is unmounted, the btrfs put root() function is called against the already freed reloc root.

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