CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's NFS server, specifically in the handling of NFSv4 open owners during the reaping of timed-out entries. This flaw can lead to a use-after-free condition, potentially allowing an attacker to exploit freed memory, which could result in system instability or unauthorized access. System administrators and developers managing NFS services on Linux should prioritize addressing this vulnerability to ensure the integrity and security of their systems.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent client use-after-free during close_lru reaping An nfs4_openowner left on nn->close_lru after its final CLOSE keeps its last closed stateid in oo_last_closed_stid, holding only a raw pointer to its nfs4_client. The laundromat reaps timed-out entries, drops nn->client_lock, and calls nfs4_put_stid(), which dereferences the client through cl_lock. Nothing pins the client across that window, so a concurrent force_expire_client() can free it and nfs4_put_stid() reads freed memory. __destroy_client() hits the same race, walking clp->cl_openowners without cl_lock. Pin the client with cl_rpc_users before dropping client_lock, and skip clients already expiring. __destroy_client() then cleans up its own close_lru entries through release_last_closed_stateid(), so teardown no longer races the laundromat.