CVE-2021-47579: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ovl: fix warning in ovl_create_real() Syzbot triggered the following warning in ovl_workdir_create() -> ovl_create_real(): if (!err && WARN_ON(!newdentry->d_inode)) { The reason is that the cgroup2 filesystem returns from mkdir without instantiating the new dentry. Weird filesystems such as this will be rejected by overlayfs at a later stage during setup, but to prevent such a warning, call ovl_mkdir_real() directly from ovl_workdir_create() and reject this case early.

Affected products

• Linux Linux Kernel: before 4.19.222 (fixed in 4.19.222); from 4.20, before 5.4.168 (fixed in 5.4.168); from 5.5, before 5.10.88 (fixed in 5.10.88); from 5.11, before 5.15.11 (fixed in 5.15.11)

Published 2024-06-19. Last modified 2026-06-17.