From: Oleg Nesterov <oleg@tv-sign.ru>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>,
Roland McGrath <roland@redhat.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH] tty: fix leakage of -ERESTARTSYS to userland
Date: Tue, 29 May 2007 22:44:35 +0400 [thread overview]
Message-ID: <20070529184435.GA174@tv-sign.ru> (raw)
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>
--- t/drivers/char/n_tty.c~ 2007-04-05 12:18:26.000000000 +0400
+++ t/drivers/char/n_tty.c 2007-05-28 10:57:58.000000000 +0400
@@ -1191,6 +1191,7 @@ static int job_control(struct tty_struct
is_current_pgrp_orphaned())
return -EIO;
kill_pgrp(task_pgrp(current), SIGTTIN, 1);
+ set_thread_flag(TIF_SIGPENDING);
return -ERESTARTSYS;
}
}
--- t/drivers/char/tty_io.c~ 2007-04-05 12:18:26.000000000 +0400
+++ t/drivers/char/tty_io.c 2007-05-29 22:15:52.000000000 +0400
@@ -1121,7 +1121,8 @@ int tty_check_change(struct tty_struct *
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;
}
next reply other threads:[~2007-05-29 18:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-29 18:44 Oleg Nesterov [this message]
2007-05-30 18:05 ` [PATCH] tty: fix leakage of -ERESTARTSYS to userland Andrew Morton
2007-05-30 19:18 ` Oleg Nesterov
2007-05-31 0:48 ` Satoru Takeuchi
2007-05-31 1:08 ` Roland McGrath
2007-05-31 1:55 ` Satoru Takeuchi
2007-05-31 7:40 ` Roland McGrath
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