net: lantiq_xrx200: confirm skb is allocated before using

xrx200_hw_receive() assumes build_skb() always works and goes straight to skb_reserve(). However, build_skb() can fail under memory pressure. Add a check in case build_skb() failed to allocate and return NULL. Fixes: e015593 ("net: lantiq_xrx200: convert to build_skb") Reported-by: Eric Dumazet <[email protected]> Signed-off-by: Aleksander Jan Bajkowski <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]>
kawasaki · Aug 25, 2022 · c8b0437 · c8b0437
1 parent a3a57bf
commit c8b0437
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
@@ -239,6 +239,12 @@ static int xrx200_hw_receive(struct xrx200_chan *ch)
 	}
 
 	skb = build_skb(buf, priv->rx_skb_size);
+	if (!skb) {
+		skb_free_frag(buf);
+		net_dev->stats.rx_dropped++;
+		return -ENOMEM;
+	}
+
 	skb_reserve(skb, NET_SKB_PAD);
 	skb_put(skb, len);