CVE-2022-49304 drivers: tty: serial: Fix deadlock in sa1100_set_termios()
A race condition in the Linux kernel's sa1100 serial driver causes a deadlock, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49304?
CVE-2022-49304 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
drivers: tty: serial: Fix deadlock in sa1100_set_termios()
There is a deadlock in sa1100_set_termios(), which is shown below:
(Thread 1) | (Thread 2) | sa1100_enable_ms() sa1100_set_termios() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) ... | sa1100_timeout() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | ...
We hold sport->port.lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need sport->port.lock in position (2) of thread 2. As a result, sa1100_set_termios() will block forever.
This patch moves del_timer_sync() before spin_lock_irqsave() in order to prevent the deadlock.
Weakness: CWE-667
Which versions are affected by CVE-2022-49304?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49304?
Apply the vendor's patch.
Is CVE-2022-49304 being exploited?
There is no known exploitation of CVE-2022-49304 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49304, GHSA-6r4h-5jp9-8j35, UBUNTU-CVE-2022-49304.