linux-kernel - [PATCH 2/3] tty: Fix unbalanced BKL handling in error path

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Date:	Thu, 13 May 2010 12:16:38 -0700
From:	Greg Kroah-Hartman <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org
Cc:	Alan Cox <alan@...ux.intel.com>, stable <stable@...nel.org>,
	Greg Kroah-Hartman <gregkh@...e.de>
Subject: [PATCH 2/3] tty: Fix unbalanced BKL handling in error path

From: Alan Cox <alan@...ux.intel.com>

Arnd noted:

After the "retry_open:" label, we first get the tty_mutex
and then the BKL. However a the end of tty_open, we jump
back to retry_open with the BKL still held. If we run into
this case, the tty_open function will be left with the BKL
still held.

Signed-off-by: Alan Cox <alan@...ux.intel.com>
Acked-by: Arnd Bergmann <arnd@...db.de>
Cc: stable <stable@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
---
 drivers/char/tty_io.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 6da962c..d71f0fc 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1875,6 +1875,7 @@ got_driver:
 		 */
 		if (filp->f_op == &hung_up_tty_fops)
 			filp->f_op = &tty_fops;
+		unlock_kernel();
 		goto retry_open;
 	}
 	unlock_kernel();
-- 
1.7.1

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