Bug 2451239 (CVE-2026-23281)

Summary: CVE-2026-23281 kernel: wifi: libertas: fix use-after-free in lbs_free_adapter()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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OS: Linux   
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A flaw was found in the Linux kernel's Marvell Libertas Wi-Fi driver. This vulnerability, a use-after-free, occurs because the system does not properly synchronize the freeing of memory with ongoing timer operations. If a timer attempts to access resources after they have been released, it can lead to system instability or crashes. In some scenarios, this type of flaw could potentially be exploited by an attacker to execute unauthorized code.
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Description OSIDB Bzimport 2026-03-25 11:06:27 UTC
In the Linux kernel, the following vulnerability has been resolved:

wifi: libertas: fix use-after-free in lbs_free_adapter()

The lbs_free_adapter() function uses timer_delete() (non-synchronous)
for both command_timer and tx_lockup_timer before the structure is
freed. This is incorrect because timer_delete() does not wait for
any running timer callback to complete.

If a timer callback is executing when lbs_free_adapter() is called,
the callback will access freed memory since lbs_cfg_free() frees the
containing structure immediately after lbs_free_adapter() returns.

Both timer callbacks (lbs_cmd_timeout_handler and lbs_tx_lockup_handler)
access priv->driver_lock, priv->cur_cmd, priv->dev, and other fields,
which would all be use-after-free violations.

Use timer_delete_sync() instead to ensure any running timer callback
has completed before returning.

This bug was introduced in commit 8f641d93c38a ("libertas: detect TX
lockups and reset hardware") where del_timer() was used instead of
del_timer_sync() in the cleanup path. The command_timer has had the
same issue since the driver was first written.