CVE-2025-22026

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.

This vulnerability is rated as Moderate impact because triggering the condition requires local privileges to initialize or tear down network namespaces with NFS server instances, or inducing memory exhaustion during procfs registration. The issue is confined to systems actively operating the NFS daemon, which is not active by default on standard Red Hat Enterprise Linux installations. An unprivileged remote attacker cannot directly trigger this flaw, limiting the blast radius to local kernel warnings or cleanup errors during deconstruction.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.