From: Luiz Augusto von Dentz luiz.von.dentz@intel.com
[ Upstream commit 7cf3b1dd6aa603fd80969e9e7160becf1455a0eb ]
When receiving L2CAP_CREDIT_BASED_CONNECTION_REQ the remote may request more channels than allowed by the spec (10 octecs = 5 CIDs) so this checks if the number of channels is bigger than the maximum allowed and respond with an error.
Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Marcel Holtmann marcel@holtmann.org Stable-dep-of: 9aa9d9473f15 ("Bluetooth: L2CAP: Fix responding with wrong PDU type") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/bluetooth/l2cap.h | 1 + net/bluetooth/l2cap_core.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h index 9b8000869b078..7f9d0ab76b14f 100644 --- a/include/net/bluetooth/l2cap.h +++ b/include/net/bluetooth/l2cap.h @@ -493,6 +493,7 @@ struct l2cap_le_credits {
#define L2CAP_ECRED_MIN_MTU 64 #define L2CAP_ECRED_MIN_MPS 64 +#define L2CAP_ECRED_MAX_CID 5
struct l2cap_ecred_conn_req { __le16 psm; diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index bde90df6b4976..b01677882e38c 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -5952,7 +5952,7 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, struct l2cap_ecred_conn_req *req = (void *) data; struct { struct l2cap_ecred_conn_rsp rsp; - __le16 dcid[5]; + __le16 dcid[L2CAP_ECRED_MAX_CID]; } __packed pdu; struct l2cap_chan *chan, *pchan; u16 mtu, mps; @@ -5969,6 +5969,14 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, goto response; }
+ cmd_len -= sizeof(*req); + num_scid = cmd_len / sizeof(u16); + + if (num_scid > ARRAY_SIZE(pdu.dcid)) { + result = L2CAP_CR_LE_INVALID_PARAMS; + goto response; + } + mtu = __le16_to_cpu(req->mtu); mps = __le16_to_cpu(req->mps);
@@ -6013,8 +6021,6 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, }
result = L2CAP_CR_LE_SUCCESS; - cmd_len -= sizeof(*req); - num_scid = cmd_len / sizeof(u16);
for (i = 0; i < num_scid; i++) { u16 scid = __le16_to_cpu(req->scid[i]);