tty: fix leakage of -ERESTARTSYS to userland
authorOleg Nesterov <oleg@tv-sign.ru>
Fri, 1 Jun 2007 07:46:53 +0000 (00:46 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Fri, 1 Jun 2007 15:18:29 +0000 (08:18 -0700)
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>
drivers/char/n_tty.c
drivers/char/tty_io.c

index b3d4ccc33a47e777d1a391ae9a85bde2f450051e..154f42203b0569c4f53c306376c6720e73cfa33d 100644 (file)
@@ -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;
                }
        }
index 75d2a46e106fedf09630958ca24c1bf2909a25ad..3752edc30c366c7940812fb25c2569c7f88d3b79 100644 (file)
@@ -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;
 }