CVE-2026-90373

wifi: mt76: mt7915: clear wcid mask under mutex after RCU pointer clear

Published Sep 17, 2026 CVSS n/a EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-362
Type Values Removed Values Added
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.
Title wifi: mt76: mt7915: clear wcid mask under mutex after RCU pointer clear
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 30, 2026, 12:35 PM
Reserved
Sep 11, 2026, 7:38 PM
Status
Received
Published
Sep 17, 2026, 5:17 PM
Modified
Oct 30, 2026, 1:20 PM