CVE-2026-43381 nouveau/dpcd: return EBUSY for aux xfer if the device is asleep

Medium 5.5 Published 8 May 2026 Updated 11 May 2026

A local attacker can trigger a kernel crash in the nouveau driver by accessing DP aux interfaces while the device is runtime suspended.

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-2026-43381?

CVE-2026-43381 is a medium-severity denial of service vulnerability in Linux kernel, published on 8 May 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:

nouveau/dpcd: return EBUSY for aux xfer if the device is asleep

If we have runtime suspended, and userspace wants to use /dev/drm_dp_* then just tell it the device is busy instead of crashing in the GSP code.

WARNING: CPU: 2 PID: 565741 at drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/rpc.c:164 r535_gsp_msgq_wait+0x9a/0xb0 [nouveau] CPU: 2 UID: 0 PID: 565741 Comm: fwupd Not tainted 6.18.10-200.fc43.x86_64 #1 PREEMPT(lazy) Hardware name: LENOVO 20QTS0PQ00/20QTS0PQ00, BIOS N2OET65W (1.52 ) 08/05/2024 RIP: 0010:r535_gsp_msgq_wait+0x9a/0xb0 [nouveau]

This is a simple fix to get backported. We should probably engineer a proper power domain solution to wake up devices and keep them awake while fw updates are happening.

Which versions are affected by CVE-2026-43381?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-43381?

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-2026-43381 being exploited?

There is no known exploitation of CVE-2026-43381 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-43381, DEBIAN-CVE-2026-43381, GHSA-gwm9-34wj-g7pc, ROOT-OS-DEBIAN-11-CVE-2026-43381, ROOT-OS-UBUNTU-2204-CVE-2026-43381, ROOT-OS-UBUNTU-2404-CVE-2026-43381 and 1 more.