Bug 2347668 (CVE-2022-49305) - CVE-2022-49305 kernel: drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop()
Summary: CVE-2022-49305 kernel: drivers: staging: rtl8192u: Fix deadlock in ieee80211_...
Keywords:
Status: NEW
Alias: CVE-2022-49305
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: 2025-02-26 03:02 UTC by OSIDB Bzimport
Modified: 2025-02-26 16:05 UTC (History)
5 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2025-02-26 03:02:31 UTC
In the Linux kernel, the following vulnerability has been resolved:

drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop()

There is a deadlock in ieee80211_beacons_stop(), which is shown below:

   (Thread 1)              |      (Thread 2)
                           | ieee80211_send_beacon()
ieee80211_beacons_stop()   |  mod_timer()
 spin_lock_irqsave() //(1) |  (wait a time)
 ...                       | ieee80211_send_beacon_cb()
 del_timer_sync()          |  spin_lock_irqsave() //(2)
 (wait timer to stop)      |  ...

We hold ieee->beacon_lock in position (1) of thread 1 and use
del_timer_sync() to wait timer to stop, but timer handler
also need ieee->beacon_lock in position (2) of thread 2.
As a result, ieee80211_beacons_stop() will block forever.

This patch extracts del_timer_sync() from the protection of
spin_lock_irqsave(), which could let timer handler to obtain
the needed lock.

Comment 1 Mauro Matteo Cascella 2025-02-26 10:47:53 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022635-CVE-2022-49305-9a46@gregkh/T


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