Bug 2536649 (CVE-2026-90367)

Summary: CVE-2026-90367 kernel: wifi: mt76: mt7996: hold dev->mt76.mutex while disabling tx worker in SER
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's `mt7996` Wi-Fi driver. The driver fails to properly hold a mutex, which is a mechanism to prevent simultaneous access to shared resources, when disabling a transmit worker during System Error Recovery (SER). This oversight creates a race condition where a concurrent channel switch operation can lead to the corruption of data transfer descriptors or tokens. The most important consequence is potential system instability or a denial of service, where the system becomes unresponsive or crashes.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-17 19:02:20 UTC 
In the Linux kernel, the following vulnerability has been resolved:

wifi: mt76: mt7996: hold dev->mt76.mutex while disabling tx worker in SER

mt7996_mac_reset_work() parked the tx worker and disabled the RX/TX NAPIs
before taking dev->mt76.mutex. mt76_worker_disable()/_enable() are plain
kthread park/unpark, not refcounted, and __mt76_set_channel() toggles the
same worker and the MT76_RESET bit under the mutex. An L1 SER racing a
channel switch could therefore have the worker unparked and MT76_RESET
cleared while the reset path resets the DMA rings, corrupting descriptors
or tokens. Take the mutex before disabling the worker, as mt7915 does.
Comment 1 gkamathe 2026-09-22 08:12:19 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90367.mbox