Bluetooth: Fix using uninitialized option in RFCMode

commit 8f321f853ea33330c7141977cd34804476e2e07e upstream.

If remote device sends bogus RFC option with invalid length,
undefined options values are used. Fix this by using defaults when
remote misbehaves.

This also fixes the following warning reported by gcc 4.7.0:

net/bluetooth/l2cap_core.c: In function 'l2cap_config_rsp':
net/bluetooth/l2cap_core.c:3302:13: warning: 'rfc.max_pdu_size' may be used uninitialized in this function [-Wmaybe-uninitialized]
net/bluetooth/l2cap_core.c:3266:24: note: 'rfc.max_pdu_size' was declared here
net/bluetooth/l2cap_core.c:3298:25: warning: 'rfc.monitor_timeout' may be used uninitialized in this function [-Wmaybe-uninitialized]
net/bluetooth/l2cap_core.c:3266:24: note: 'rfc.monitor_timeout' was declared here
net/bluetooth/l2cap_core.c:3297:25: warning: 'rfc.retrans_timeout' may be used uninitialized in this function [-Wmaybe-uninitialized]
net/bluetooth/l2cap_core.c:3266:24: note: 'rfc.retrans_timeout' was declared here
net/bluetooth/l2cap_core.c:3295:2: warning: 'rfc.mode' may be used uninitialized in this function [-Wmaybe-uninitialized]
net/bluetooth/l2cap_core.c:3266:24: note: 'rfc.mode' was declared here

Signed-off-by: Szymon Janc <szymon.janc@tieto.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 627c35445a13bcf974f67ed0c88b0b8d0aa09ff9..fa07aed3983b7e557c38123df84015ea2302d358 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -2585,12 +2585,14 @@ static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len)
        while (len >= L2CAP_CONF_OPT_SIZE) {
                len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
 
-               switch (type) {
-               case L2CAP_CONF_RFC:
-                       if (olen == sizeof(rfc))
-                               memcpy(&rfc, (void *)val, olen);
-                       goto done;
-               }
+               if (type != L2CAP_CONF_RFC)
+                       continue;
+
+               if (olen != sizeof(rfc))
+                       break;
+
+               memcpy(&rfc, (void *)val, olen);
+               goto done;
        }
 
        /* Use sane default values in case a misbehaving remote device