On 1/31/19 5:14 PM, Greg KH wrote:
On Thu, Jan 31, 2019 at 04:23:59PM -0700, Shuah Khan wrote:tty_set_termios() has the following WARN_ON which can be triggered with a syscall to invoke TIOCSETD __NR_ioctl. WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER); Reference: https://syzkaller.appspot.com/bug?id=2410d22f1d8e5984217329dd0884b01d99e3e48d The problem started with commit 7721383f4199 ("Bluetooth: hci_uart: Support operational speed during setup") which introduced a new way for how tty_set_termios() could end up being called for a master pty. Fix the problem by preventing setting the HCI line discipline for PTYs from hci_uart_setup() and hci_uart_set_flow_control(). The reproducer is used to reproduce the problem and verify the fix. Reported-by: syzbot+a950165cbb86bdd023a4@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Shuah Khan <shuah@xxxxxxxxxx> --- drivers/bluetooth/hci_ldisc.c | 11 +++++++++++ 1 file changed, 11 insertions(+)I think the subject should be something like: "bluetooth: hci: Fix warning in tty_set_termios()" it isn't a tty core problem :)
Yes. Sorry about that. Will get it right in my v3. thanks, -- Shuah
