From 36e999a83a4a4badd389901eb6d23a30e199b8db Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Thu, 8 Dec 2011 17:23:21 -0800 Subject: [PATCH] Bluetooth: Prevent uninitialized data access in L2CAP configuration When configuring an ERTM or streaming mode connection, remote devices are expected to send an RFC option in a successful config response. A misbehaving remote device might not send an RFC option, and the L2CAP code should not access uninitialized data in this case. Signed-off-by: Mat Martineau Acked-by: Marcel Holtmann Signed-off-by: Gustavo F. Padovan --- net/bluetooth/l2cap_core.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 5ea94a1..17b5b1c 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -2152,7 +2152,7 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, voi void *ptr = req->data; int type, olen; unsigned long val; - struct l2cap_conf_rfc rfc; + struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data); @@ -2271,6 +2271,16 @@ static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len) } } + /* Use sane default values in case a misbehaving remote device + * did not send an RFC option. + */ + rfc.mode = chan->mode; + rfc.retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO); + rfc.monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO); + rfc.max_pdu_size = cpu_to_le16(chan->imtu); + + BT_ERR("Expected RFC option was not found, using defaults"); + done: switch (rfc.mode) { case L2CAP_MODE_ERTM: -- 2.7.4