Bug 2540492 (CVE-2026-93804) - CVE-2026-93804 kernel: wifi: mac80211: ibss: wait for in-flight TX on disconnect
Summary: CVE-2026-93804 kernel: wifi: mac80211: ibss: wait for in-flight TX on disconnect
Keywords:
Status: NEW
Alias: CVE-2026-93804
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-24 17:00 UTC by OSIDB Bzimport
Modified: 2026-09-28 12:39 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-09-24 17:00:26 UTC
In the Linux kernel, the following vulnerability has been resolved:

wifi: mac80211: ibss: wait for in-flight TX on disconnect

While leaving an IBSS in ieee80211_ibss_disconnect() mac80211 flushes
stations, turns the carrier off and immediately tells the driver to
leave as well. While there may be synchronize_net() in station flush
and in this code later, packets can still be transmitted due to
cross-CPU race conditions after carrier off is set.
Therefore, it's possible for a race to happen where a TX to the
driver occurs while or after telling it to leave the IBSS. This can
be confusing to drivers, and in the case of iwlwifi leads to an
attempt to use invalid queues.

Move netif_carrier_off() to occur before sta_info_flush() during
IBSS disconnect, and add synchronize_net() if flushing didn't,
so that the synchronize_net() always happens between turning the
carrier off and telling the driver, avoiding this race.


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