- Description
- In the Linux kernel, the following vulnerability has been resolved:
gpio: mpsse: fix race when arming the IRQ poll worker
gpio_mpsse_irq_enable() arms the poll worker before publishing it:
schedule_work() runs before the worker is added to priv->workers. If
gpio_mpsse_disconnect() walks the list in that window it misses the
worker, and once disconnect returns, the USB core frees mpsse_priv
while the orphaned gpio_mpsse_poll() work keeps accessing it, causing
a use-after-free.
Fix this by publishing and arming the worker in one irq_spin
critical section. Teardown walks the same list under irq_spin, so a
worker found on the list is guaranteed to be armed, and
cancel_work_sync() handles it whether it is queued or running.
A worker armed after the disconnect walk would still be missed, so
also set a new priv->dying flag under irq_spin before the teardown
walk, and check it in the same critical section, freeing it via
kfree_rcu() instead when the device is going away, since kfree()
would be called with the IRQ core's raw spinlock held and may sleep
on PREEMPT_RT. schedule_work() is safe to call with irq_spin held,
and the next probe gets a fresh mpsse_priv, so the flag never needs
to be cleared.
This issue was found by an in-house static analysis tool.
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- NVD status
- Received