CVE-2026-90373 wifi: mt76: mt7915: clear wcid mask under mutex after RCU pointer clear
A race condition in the mt7915 WiFi driver allows concurrent interface removal and allocation to corrupt state, potentially leading to privilege escalation or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90373?
CVE-2026-90373 is a vulnerability in Linux, published on 17 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:
wifi: mt76: mt7915: clear wcid mask under mutex after RCU pointer clear
mt7915_remove_interface() cleared the wcid mask bit with no lock held and before clearing the RCU wcid pointer. The mask is a non-atomic RMW shared with the allocators, which all run under dev->mt76.mutex; on DBDC the two wiphys share one mt76_dev, so this raced add_interface/sta_add on the other band and could leak or double-hand-out a wcid. Clearing the bit before the RCU pointer also let a concurrent allocation reuse the index and publish its wcid, which the subsequent NULL assignment then wiped. Move the clear into the existing mutex section, after the RCU pointer is cleared.
Which versions are affected by CVE-2026-90373?
How do I fix CVE-2026-90373?
Apply the vendor's patch.
Is CVE-2026-90373 being exploited?
There is no known exploitation of CVE-2026-90373 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90373, DEBIAN-CVE-2026-90373, GHSA-4c4x-fg8c-5526, UBUNTU-CVE-2026-90373.