Linux Kernel: libertas WiFi Driver UAF due to timer_delete in lbs_free_adapter()
CVE-2026-23281 Published on March 25, 2026
wifi: libertas: fix use-after-free in lbs_free_adapter()
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.
Products Associated with CVE-2026-23281
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Affected Versions
Linux:- Version 954ee164f4f4598afc172c0ec3865d0352e55a0b and below 3f9dec4a6d95d7f1f5e9e9dfdfa173c053bba8dc is affected.
- Version 954ee164f4f4598afc172c0ec3865d0352e55a0b and below 3c5c818c78b03a1725f3dcd566865c77b48dd3a6 is affected.
- Version 954ee164f4f4598afc172c0ec3865d0352e55a0b and below d0155fe68f31b339961cf2d4f92937d57e9384e6 is affected.
- Version 954ee164f4f4598afc172c0ec3865d0352e55a0b and below ed7d30f90b77f73a47498686ede83f622b7e4f0d is affected.
- Version 954ee164f4f4598afc172c0ec3865d0352e55a0b and below a9f55b14486426d907459bced5825a25063bd922 is affected.
- Version 954ee164f4f4598afc172c0ec3865d0352e55a0b and below 03cc8f90d0537fcd4985c3319b4fafbf2e3fb1f0 is affected.
- Version 2.6.24 is affected.
- Before 2.6.24 is unaffected.
- Version 6.1.167, <= 6.1.* is unaffected.
- Version 6.6.130, <= 6.6.* is unaffected.
- Version 6.12.78, <= 6.12.* is unaffected.
- Version 6.18.17, <= 6.18.* is unaffected.
- Version 6.19.7, <= 6.19.* is unaffected.
- Version 7.0-rc2, <= * is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.