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: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 888fdca93014e74deb67e0cb8942a5d06f704c95..dd76177556e375413ddbf4229c402680244a9350 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -2264,12 +2264,14 @@ 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