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Date: Sun, 8 May 2011 21:57:25 +0200
Message-ID: <BANLkTik7WyQ977-+8XapTgBrVRMyexyHKg@mail.gmail.com>
Subject: Bluetooth: l2cap and rfcomm: fix 1 byte infoleak to userspace.
From: Filip Palian <s3810@pjwstk.edu.pl>
To: Marcel Holtmann <marcel@holtmann.org>, "Gustavo F. Padovan" <padovan@profusion.mobi>,
	"David S. Miller" <davem@davemloft.net>, linux-bluetooth@vger.kernel.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: security@kernel.org, oss-security@lists.openwall.com
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List-ID: <linux-bluetooth.vger.kernel.org>

Hi,

Structures "l2cap_conninfo" and "rfcomm_conninfo" have one padding
byte each. This byte in "cinfo" is copied to userspace uninitialized.

patch no.1:
-- cut --
--- a/net/bluetooth/l2cap_sock.c        2011-05-04 03:59:13.000000000 +0100
+++ b/net/bluetooth/l2cap_sock.c        2011-05-08 18:57:20.000000000 +0100
@@ -446,6 +446,7 @@ static int l2cap_sock_getsockopt_old(str
                        break;
                }

+               memset(&cinfo, 0, sizeof(cinfo));
                cinfo.hci_handle = l2cap_pi(sk)->conn->hcon->handle;
                memcpy(cinfo.dev_class, l2cap_pi(sk)->conn->hcon->dev_class, 3);

-- cut --

patch no.2:
-- cut --
--- a/net/bluetooth/rfcomm/sock.c       2011-05-04 03:59:13.000000000 +0100
+++ b/net/bluetooth/rfcomm/sock.c       2011-05-08 19:00:24.000000000 +0100
@@ -787,6 +787,7 @@ static int rfcomm_sock_getsockopt_old(st

                l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;

+               memset(&cinfo, 0, sizeof(cinfo));
                cinfo.hci_handle = l2cap_pi(l2cap_sk)->conn->hcon->handle;
                memcpy(cinfo.dev_class,
l2cap_pi(l2cap_sk)->conn->hcon->dev_class, 3);
-- cut --

Found by Marek Kroemeke and Filip Palian. Special thanks to Vasiliy
Kulikov for verifying this bug.


Best regards.