CVE-2022-49304

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drivers: tty: serial: Fix deadlock in sa1100_set_termios()<br /> <br /> There is a deadlock in sa1100_set_termios(), which is shown<br /> below:<br /> <br /> (Thread 1) | (Thread 2)<br /> | sa1100_enable_ms()<br /> sa1100_set_termios() | mod_timer()<br /> spin_lock_irqsave() //(1) | (wait a time)<br /> ... | sa1100_timeout()<br /> del_timer_sync() | spin_lock_irqsave() //(2)<br /> (wait timer to stop) | ...<br /> <br /> We hold sport-&gt;port.lock in position (1) of thread 1 and<br /> use del_timer_sync() to wait timer to stop, but timer handler<br /> also need sport-&gt;port.lock in position (2) of thread 2. As a result,<br /> sa1100_set_termios() will block forever.<br /> <br /> This patch moves del_timer_sync() before spin_lock_irqsave()<br /> in order to prevent the deadlock.