From: Gustavo F. Padovan <padovan@profusion.mobi>
Date: Sat, 1 May 2010 19:15:45 +0000 (-0300)
Subject: Bluetooth: Prevents buffer overflow on l2cap_ertm_reassembly_sdu()
X-Git-Tag: v2.6.35-rc1~473^2~178
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=4178ba462a3e8ab5094e69606f01d9e95f2d5ea6;p=~shefty%2Frdma-dev.git

Bluetooth: Prevents buffer overflow on l2cap_ertm_reassembly_sdu()

The checks should be done before the the memcpy to avoid buffer
overflow.

Reported-by: João Paulo Rechi Vita <jprvita@profusion.mobi>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
---

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index fe663e9c668..9ef01c32b3a 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -3470,12 +3470,12 @@ static int l2cap_ertm_reassembly_sdu(struct sock *sk, struct sk_buff *skb, u16 c
 		if (!pi->sdu)
 			goto disconnect;
 
-		memcpy(skb_put(pi->sdu, skb->len), skb->data, skb->len);
-
 		pi->partial_sdu_len += skb->len;
 		if (pi->partial_sdu_len > pi->sdu_len)
 			goto drop;
 
+		memcpy(skb_put(pi->sdu, skb->len), skb->data, skb->len);
+
 		break;
 
 	case L2CAP_SDU_END:
@@ -3486,8 +3486,6 @@ static int l2cap_ertm_reassembly_sdu(struct sock *sk, struct sk_buff *skb, u16 c
 			goto disconnect;
 
 		if (!(pi->conn_state & L2CAP_CONN_SAR_RETRY)) {
-			memcpy(skb_put(pi->sdu, skb->len), skb->data, skb->len);
-
 			pi->partial_sdu_len += skb->len;
 
 			if (pi->partial_sdu_len > pi->imtu)
@@ -3495,6 +3493,8 @@ static int l2cap_ertm_reassembly_sdu(struct sock *sk, struct sk_buff *skb, u16 c
 
 			if (pi->partial_sdu_len != pi->sdu_len)
 				goto drop;
+
+			memcpy(skb_put(pi->sdu, skb->len), skb->data, skb->len);
 		}
 
 		_skb = skb_clone(pi->sdu, GFP_ATOMIC);