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tty: set_termios/set_termiox should not return -EINTR 

See https://bugzilla.redhat.com/show_bug.cgi?id=904907
read command causes bash to abort with double free or corruption (out).

A simple test-case from Roman:

	// Compile the reproducer and send sigchld ti that process.
	// EINTR occurs even if SA_RESTART flag is set.

	void handler(int sig)
	{
	}

	main()
	{
	  struct sigaction act;
	  act.sa_handler = handler;
	  act.sa_flags = SA_RESTART;
	  sigaction (SIGCHLD, &act, 0);
	  struct termio ttp;
	  ioctl(0, TCGETA, &ttp);
	  while(1)
	  {
	    if (ioctl(0, TCSETAW, ttp) < 0)
	      {
		if (errno == EINTR)
		{
		  fprintf(stderr, "BUG!"); return(1);
		}
	      }
	  }
	}

Change set_termios/set_termiox to return -ERESTARTSYS to fix this
particular problem.

I didn't dare to change other EINTR's in drivers/tty/, but they look
equally wrong.

Reported-by: Roman Rakus <rrakus@redhat.com>
Reported-by: Lingzhu Xiang <lxiang@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Oleg Nesterov 2013-01-29 20:07:41 +01:00 committed by Greg Kroah-Hartman
parent 4d9b109060
commit 183d95cdd8
1 changed files with 2 additions and 2 deletions
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4
drivers/tty/tty_ioctl.c
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@ -617,7 +617,7 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
if (opt & TERMIOS_WAIT) {
tty_wait_until_sent(tty, 0);
if (signal_pending(current))
return -EINTR;
return -ERESTARTSYS;
}
tty_set_termios(tty, &tmp_termios);
@ -684,7 +684,7 @@ static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
if (opt & TERMIOS_WAIT) {
tty_wait_until_sent(tty, 0);
if (signal_pending(current))
return -EINTR;
return -ERESTARTSYS;
}
mutex_lock(&tty->termios_mutex);