[PATCH 2.6.32 04/62] TTY: drop driver reference in tty_open fail path

[Willy Tarreau]

2.6.32-longterm review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Slaby <jslaby@xxxxxxx>

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@xxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Acked-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
[bwh: Backported to 2.6.32: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>

CVE-2011-5321

Signed-off-by: Willy Tarreau <w@xxxxxx>
---
 drivers/char/tty_io.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index cbdd1698..6c71534 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);
 		}
 	}
-- 
1.7.12.2.21.g234cd45.dirty



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