CVE-2025-71084 RDMA/cm: Fix leaking the multicast GID table reference

Medium 5.5 Published 13 Jan 2026 Updated 19 Oct 2026

A reference leak in the Linux kernel RDMA connection manager can cause resource exhaustion and system warnings, potentially leading to denial of service.

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-2025-71084?

CVE-2025-71084 is a medium-severity denial of service vulnerability in Linux kernel, published on 13 Jan 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:

RDMA/cm: Fix leaking the multicast GID table reference

If the CM ID is destroyed while the CM event for multicast creating is still queued the cancel_work_sync() will prevent the work from running which also prevents destroying the ah_attr. This leaks a refcount and triggers a WARN:

GID entry ref leak for dev syz1 index 2 ref=573 WARNING: CPU: 1 PID: 655 at drivers/infiniband/core/cache.c:809 release_gid_table drivers/infiniband/core/cache.c:806 [inline] WARNING: CPU: 1 PID: 655 at drivers/infiniband/core/cache.c:809 gid_table_release_one+0x284/0x3cc drivers/infiniband/core/cache.c:886

Destroy the ah_attr after canceling the work, it is safe to call this twice.

Weakness: CWE-401

Which versions are affected by CVE-2025-71084?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-71084?

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-2025-71084 being exploited?

There is no known exploitation of CVE-2025-71084 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2025-71084, DEBIAN-CVE-2025-71084, GHSA-q8q5-8hv7-m52r, ROOT-OS-DEBIAN-11-CVE-2025-71084, ROOT-OS-DEBIAN-12-CVE-2025-71084, ROOT-OS-DEBIAN-13-CVE-2025-71084 and 3 more.