CVE-2022-0812

What it actually does

The flaw in net/sunrpc/xprtrdma/rpc_rdma.c permits a local user to trigger NFS/RDMA operations that inadvertently copy uninitialized or sensitive kernel memory into responses visible to the caller.

Why it matters to the business

Attackers who already possess a low-privileged account on a Linux system can obtain kernel memory contents that may contain credentials, addresses, or other data useful for escalating privileges or bypassing protections.

How an attack unfolds

An authenticated local user crafts NFS/RDMA requests that exercise the vulnerable RDMA transport path; the kernel leaks memory contents back to the user process without sanitization, allowing the attacker to harvest sensitive information for follow-on attacks.

How to fix it

Upgrade the Linux kernel to a version containing commit 912288442cb2f431bf3c8cb097a5de83bc6dbac1 or later; apply the fix via distribution package updates or rebuild from the corrected source.

How to confirm the fix worked

Verify the running kernel contains commit 912288442cb2f431bf3c8cb097a5de83bc6dbac1; confirm the vulnerable function in rpc_rdma.c no longer performs unsanitized copies; retest NFS/RDMA paths for information disclosure.

Typical attack path

1. Obtain normal user shell on affected Linux host
2. Load or exercise NFS/RDMA client functionality
3. Send specially formed RDMA RPC messages
4. Receive and parse kernel memory disclosures
5. Use leaked data to inform local privilege escalation

How to detect it

Review kernel audit logs and system call traces for unusual NFS/RDMA activity from unprivileged processes; examine process memory dumps or strace output for unexpected data patterns originating from the RDMA transport layer.

What your security team should do

• Prioritize kernel updates on all systems exposing NFS/RDMA
• Restrict NFS/RDMA usage to trusted networks and authenticated clients only
• Monitor for new kernel releases and schedule patch deployment within standard change windows
• Audit systems for unnecessary NFS/RDMA exposure and disable where feasible