CVE-2026-90030 usb: dwc3: clear forceRM when issuing EndTransfer
A flaw in the Linux kernel DWC3 USB driver causes SMMU faults and system instability when aborting transfers, requiring a patch to clear the forceRM bit.
- 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-2026-90030?
CVE-2026-90030 is a high-severity denial of service vulnerability in Linux, published on 16 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:
usb: dwc3: clear forceRM when issuing EndTransfer
The forceRM bit of the DEPCMD register controls the behavior of the EndTransfer command used to stop an active transfer. Older DWC3 programming guide revisions recommended setting forceRM=1 when issuing EndTransfer. Newer programming guide revisions recommend issuing EndTransfer with forceRM cleared.
With forceRM=1 on DWC_usb31 v2.00a and v2.10a controllers, a transfer aborted through the ep_dequeue path was observed to remain active after EndTransfer completion. A subsequent StartTransfer issued on the same endpoint triggered writes associated with the aborted transfer. This resulted in an SMMU fault because the transfer buffer had already been unmapped during EndTransfer command-completion cleanup.
Using forceRM=0 eliminates the issue. Although older DWC3 programming guide revisions recommended setting forceRM=1, no issues are known from using forceRM=0. Clear forceRM when issuing EndTransfer to provide consistent EndTransfer behavior and align with newer programming guide recommendations.
Which versions are affected by CVE-2026-90030?
How do I fix CVE-2026-90030?
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-2026-90030 being exploited?
There is no known exploitation of CVE-2026-90030 in the wild and no public exploit code.
Sources
Also known as AZL-101493, BELL-CVE-2026-90030, DEBIAN-CVE-2026-90030, GHSA-xj76-5wmq-jmw6, UBUNTU-CVE-2026-90030.