From: Mathias Krause <minipli@googlemail.com>
Date: Sun, 7 Apr 2013 01:51:50 +0000 (+0000)
Subject: Bluetooth: RFCOMM - Fix missing msg_namelen update in rfcomm_sock_recvmsg()
X-Git-Tag: v2.6.34.15~83
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5f9cd45f92653b4cc8493a47c61a36f5b7426cf1;p=thirdparty%2Fkernel%2Fstable.git

Bluetooth: RFCOMM - Fix missing msg_namelen update in rfcomm_sock_recvmsg()

commit e11e0455c0d7d3d62276a0c55d9dfbc16779d691 upstream.

If RFCOMM_DEFER_SETUP is set in the flags, rfcomm_sock_recvmsg() returns
early with 0 without updating the possibly set msg_namelen member. This,
in turn, leads to a 128 byte kernel stack leak in net/socket.c.

Fix this by updating msg_namelen in this case. For all other cases it
will be handled in bt_sock_stream_recvmsg().

Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 92aa7a012110f..557122ee3e24c 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -656,6 +656,7 @@ static int rfcomm_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 
 	if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
 		rfcomm_dlc_accept(d);
+		msg->msg_namelen = 0;
 		return 0;
 	}