CVE-2026-98706: wifi: mac80211: drain PS delivery work during station teardown
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: drain PS delivery work during station teardown
Removing an AP or mesh station can notify the driver and wake TXQs after the station has already been removed from the driver, and can update numstaps and the power-save queues after station cleanup has purged them.
stadeliverpsframes() tests sta->dead only before it starts delivery. A worker that passes that test can be delayed while teardown sets sta->dead and removes the station from the driver; when it resumes it still runs the full delivery.
The existing cancelworksync() sits near the end of cleanupsinglesta(), after the final driver state transition and after PS accounting and queue purging, so it drains the worker only once the state it has to protect has already changed. Before commit d34ba2168a3c ("mac80211: don't delay station destruction") cleanup was deferred through the same ordered workqueue as the delivery work, which kept the two ordered.
Cancel the work after setting sta->dead and before moving the driver state, and move the existing cancellation to the start of cleanupsinglesta(). The first drain closes the driver-lifetime window; driver callbacks during the remaining state transitions can still queue drvdeliverwk through ieee80211stablockawake(), so retain the second drain at the start of cleanupsinglesta(). That drain also covers insertion failures, which reach cleanup without setting sta->dead.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.113-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 7.2.10-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 5.10.273 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 5.15.224 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.1.191 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.160 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.113 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.18.56 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 7.2.10 - Upgrade
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azurelinux/kernelto a version that resolves this vulnerability.Fixed in 6.6.161.1-1 - Compensating control
During station teardown, cancel the PS delivery work after setting sta->dead and before moving the station state in the driver; retain the existing cancel_work_sync() at the start of __cleanup_single_sta() so driver callbacks during remaining state transitions cannot queue drv_deliver_wk.
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Linux kernel systems using the mac80211 Wi-Fi stack are exposed when an AP or mesh station is removed while power-save frame delivery work can still be pending.
What timing is required to trigger the race?
A power-save delivery worker must pass its initial check that the station is not dead, then be delayed while station teardown marks the station dead and removes it from the driver. When the worker resumes, it can deliver frames against state that teardown has already cleaned up.
What changes mitigate the issue?
The fix drains pending power-save delivery work after the station is marked dead and before driver-state changes, and moves the existing work cancellation to the beginning of station cleanup. This prevents delayed delivery work from running after driver removal, power-save accounting updates, and queue purging.