From: Alexander Aring <aring@mojatatu.com>
Date: Mon, 2 Jul 2018 20:32:03 +0000 (-0400)
Subject: net: mac802154: tx: expand tailroom if necessary
X-Git-Tag: MMI-QSB30.62-17~983^2~71^2~89
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4a2262972b5dab51e1e09dee8992d29b4946c1ab;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

net: mac802154: tx: expand tailroom if necessary

commit f9c52831133050c6b82aa8b6831c92da2bbf2a0b upstream.

This patch is necessary if case of AF_PACKET or other socket interface
which I am aware of it and didn't allocated the necessary room.

Reported-by: David Palma <david.palma@ntnu.no>
Reported-by: Rabi Narayan Sahoo <rabinarayans0828@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c
index 7e253455f9dd..bcd1a5e6ebf4 100644
--- a/net/mac802154/tx.c
+++ b/net/mac802154/tx.c
@@ -63,8 +63,21 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
 	int ret;
 
 	if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) {
-		u16 crc = crc_ccitt(0, skb->data, skb->len);
+		struct sk_buff *nskb;
+		u16 crc;
+
+		if (unlikely(skb_tailroom(skb) < IEEE802154_FCS_LEN)) {
+			nskb = skb_copy_expand(skb, 0, IEEE802154_FCS_LEN,
+					       GFP_ATOMIC);
+			if (likely(nskb)) {
+				consume_skb(skb);
+				skb = nskb;
+			} else {
+				goto err_tx;
+			}
+		}
 
+		crc = crc_ccitt(0, skb->data, skb->len);
 		put_unaligned_le16(crc, skb_put(skb, 2));
 	}