CVE-2026-53174 ovl: keep err zero after successful ovl_cache_get()
A logic error in the Linux kernel overlayfs module can return a bogus error code, potentially causing denial of service during directory listing operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53174?
CVE-2026-53174 is a high-severity vulnerability in Linux kernel, published on 25 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ovl: keep err zero after successful ovl_cache_get()
ovl_iterate_merged() stores PTR_ERR(cache) in err before checking IS_ERR(cache). On success err holds the truncated cache pointer and can be returned as a bogus non-zero error.
The syzbot reproducer reaches this through overlay-on-overlay readdir:
getdents64 iterate_dir(outer overlay file) ovl_iterate_merged() ovl_cache_get() ovl_dir_read_merged() ovl_dir_read() iterate_dir(inner overlay file) ovl_iterate_merged()
Only compute PTR_ERR(cache) on the error path.
Which versions are affected by CVE-2026-53174?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53174?
Apply the vendor's patch.
Is CVE-2026-53174 being exploited?
There is no known exploitation of CVE-2026-53174 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2026-53174, GHSA-xxjh-4wcx-gmq5, UBUNTU-CVE-2026-53174.