Commit 36e999a8 authored by Mat Martineau's avatar Mat Martineau Committed by Gustavo F. Padovan

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: default avatarMat Martineau <mathewm@codeaurora.org>
Acked-by: default avatarMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: default avatarGustavo F. Padovan <padovan@profusion.mobi>
parent 33cb722c
...@@ -2152,7 +2152,7 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, voi ...@@ -2152,7 +2152,7 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, voi
void *ptr = req->data; void *ptr = req->data;
int type, olen; int type, olen;
unsigned long val; 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); 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) ...@@ -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: done:
switch (rfc.mode) { switch (rfc.mode) {
case L2CAP_MODE_ERTM: case L2CAP_MODE_ERTM:
......
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