CVE-2025-22026 nfsd: don't ignore the return code of svc_proc_register()
An attacker can cause a kernel warning and potential instability by triggering a failure in NFS proc file registration, requiring a kernel patch.
- 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-2025-22026?
CVE-2025-22026 is a medium-severity denial of service vulnerability in Linux kernel, published on 16 Apr 2025. 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:
nfsd: don't ignore the return code of svc_proc_register()
Currently, nfsd_proc_stat_init() ignores the return value of svc_proc_register(). If the procfile creation fails, then the kernel will WARN when it tries to remove the entry later.
Fix nfsd_proc_stat_init() to return the same type of pointer as svc_proc_register(), and fix up nfsd_net_init() to check that and fail the nfsd_net construction if it occurs.
svc_proc_register() can fail if the dentry can't be allocated, or if an identical dentry already exists. The second case is pretty unlikely in the nfsd_net construction codepath, so if this happens, return -ENOMEM.
Weakness: CWE-252
Which versions are affected by CVE-2025-22026?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-22026?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-22026 being exploited?
There is no known exploitation of CVE-2025-22026 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-62735, AZL-68985, BELL-CVE-2025-22026, DEBIAN-CVE-2025-22026, GHSA-xrr8-p4pf-hfwr, ROOT-OS-DEBIAN-11-CVE-2025-22026 and 4 more.