CVE-2026-23281

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.