A use-after-free flaw was discovered in the Linux kernel's tty subsystem, which allows for the disclosure of uncontrolled memory location and possible kernel panic. The information leak is caused by a race condition when attempting to set and read the tty line discipline. A local attacker could use the TIOCSETD (via tty_set_ldisc) to switch to a new line discipline; a concurrent call to a TIOCGETD ioctl performing a read on a given tty could then access previously allocated memory. Up to 4 bytes could be leaked when querying the line discipline or the kernel could panic with a NULL-pointer dereference.