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: v3.4.43~27
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2d97f68d03180ad0a47fdb7c02f0fecdac9ad9a7;p=karo-tx-linux.git

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

[ Upstream commit e11e0455c0d7d3d62276a0c55d9dfbc16779d691 ]

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().

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 8d1edd7207df..c79db7f7533b 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -628,6 +628,7 @@ 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;
 	}