CVE-2026-89498 orangefs: fix double-free of trailer_buf on readdir copy failure

Q: Is CVE-2026-89498 being exploited?

There is no known exploitation of CVE-2026-89498 in the wild and no public exploit code.

Not scored Published 11 Sep 2026 Updated 19 Oct 2026

A local attacker with access to /dev/pvfs2-req can trigger a double-free in the orangefs kernel module, potentially causing a system crash or arbitrary code execution.

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-2026-89498?

CVE-2026-89498 is an use after free vulnerability in Linux, published on 11 Sep 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:

orangefs: fix double-free of trailer_buf on readdir copy failure

On a readdir downcall, orangefs_devreq_write_iter() frees op->downcall.trailer_buf with vfree() when copy_from_iter_full() fails, but does not clear the pointer before goto Efault. The waiter in do_readdir() is then woken with a negative status and frees the same pointer again on its r < 0 path, causing a deterministic double-free. A client holding /dev/pvfs2-req triggers it by sending a readdir downcall whose declared trailer_size exceeds the bytes it supplies.

Clear the pointer after freeing so the readdir-side vfree() becomes a no-op.

Which versions are affected by CVE-2026-89498?

How do I fix CVE-2026-89498?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2026-89498 being exploited?