Commit 'e7f3880cd9b98c5bf9391ae7acdec82b75403776' tty: Fix recursive deadlock in tty_perform_flush() introduced a regression where tcflush() does not generate SIGTTOU for background process groups. Make sure ioctl(TCFLSH) calls tty_check_change() when invoked from the line discipline. Cc: stable@xxxxxxxxxxxxxxx # v3.10+ Reported-by: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> --- drivers/tty/tty_ioctl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 3500d41..088b4ca 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -1201,6 +1201,9 @@ int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, } return 0; case TCFLSH: + retval = tty_check_change(tty); + if (retval) + return retval; return __tty_perform_flush(tty, arg); default: /* Try the mode commands */ -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html