CVE-2026-99050 gpio: mpsse: fix race when arming the IRQ poll worker
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-99050?
CVE-2026-99050 is a high-severity vulnerability in Linux, published on 23 Oct 2026.
Official 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.
Which versions are affected by CVE-2026-99050?
How do I fix CVE-2026-99050?
Upgrade to a fixed version.
Is CVE-2026-99050 being exploited?
There is no known exploitation of CVE-2026-99050 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-99050, GHSA-77g9-3gmv-7p3q, UBUNTU-CVE-2026-99050.