Bluetooth: Check the SDU size against the MTU value

If the SDU size is greater than the MTU something is wrong, so report
an error.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
[jprvita@profusion.mobi: set err to appropriate errno value]
Signed-off-by: João Paulo Rechi Vita <jprvita@profusion.mobi>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 0889949b6896..e936913c921e 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -3338,6 +3338,11 @@ static int l2cap_sar_reassembly_sdu(struct sock *sk, struct sk_buff *skb, u16 co
                 pi->sdu_len = get_unaligned_le16(skb->data);
                 skb_pull(skb, 2);
 
+                if (pi->sdu_len > pi->imtu) {
+                        err = -EMSGSIZE;
+                        break;
+                }
+
                 pi->sdu = bt_skb_alloc(pi->sdu_len, GFP_ATOMIC);
                 if (!pi->sdu) {
                         err = -ENOMEM;