From: Jiri Slaby <jslaby@suse.cz>
Date: Wed, 12 Oct 2011 09:32:42 +0000 (+0200)
Subject: TTY: drop driver reference in tty_open fail path
X-Git-Tag: v2.6.32.68~56
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d447af56f50bdcb4d5ca378ed6b2d48fb0b973ac;p=thirdparty%2Fkernel%2Fstable.git

TTY: drop driver reference in tty_open fail path

commit c290f8358acaeffd8e0c551ddcc24d1206143376 upstream.

When tty_driver_lookup_tty fails in tty_open, we forget to drop a
reference to the tty driver. This was added by commit 4a2b5fddd5 (Move
tty lookup/reopen to caller).

Fix that by adding tty_driver_kref_put to the fail path.

I will refactor the code later. This is for the ease of backporting to
stable.

Introduced-in: v2.6.28-rc2
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[bwh: Backported to 2.6.32: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

CVE-2011-5321

Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index cbdd1698c07b8..6c7153438514d 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1779,6 +1779,7 @@ got_driver:
 
 		if (IS_ERR(tty)) {
 			mutex_unlock(&tty_mutex);
+			tty_driver_kref_put(driver);
 			return PTR_ERR(tty);
 		}
 	}