Commit 040b6362 authored Jun 01, 2007 by Oleg Nesterov Committed by Linus Torvalds Jun 01, 2007

tty: fix leakage of -ERESTARTSYS to userland



Spotted by Satoru Takeuchi.

kill_pgrp(task_pgrp(current)) sends the signal to the current's thread
group, but can choose any sub-thread as a target for signal_wake_up().
This means that job_control() and tty_check_change() may return
-ERESTARTSYS without signal_pending().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 13466c84

drivers/char/n_tty.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1191,6 +1191,7 @@ static int job_control(struct tty_struct tty, struct file file)
		is_current_pgrp_orphaned())
		return -EIO;
		kill_pgrp(task_pgrp(current), SIGTTIN, 1);
		set_thread_flag(TIF_SIGPENDING);
		return -ERESTARTSYS;
		}
		}

drivers/char/tty_io.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1148,7 +1148,8 @@ int tty_check_change(struct tty_struct * tty)
		return 0;
		if (is_current_pgrp_orphaned())
		return -EIO;
		(void) kill_pgrp(task_pgrp(current), SIGTTOU, 1);
		kill_pgrp(task_pgrp(current), SIGTTOU, 1);
		set_thread_flag(TIF_SIGPENDING);
		return -ERESTARTSYS;
		}