Commit d7ea0d9d authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: remove two BUG() from skb_checksum_help() 



I have a syzbot report that managed to get a crash in skb_checksum_help()

If syzbot can trigger these BUG(), it makes sense to replace
them with more friendly WARN_ON_ONCE() since skb_checksum_help()
can instead return an error code.

Note that syzbot will still crash there, until real bug is fixed.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 66e4c8d9

net/core/dev.c

+6 −2
Original line number Diff line number Diff line
@@ -3265,11 +3265,15 @@ int skb_checksum_help(struct sk_buff *skb) 
	}



	offset = skb_checksum_start_offset(skb);

	BUG_ON(offset >= skb_headlen(skb));

	ret = -EINVAL;

	if (WARN_ON_ONCE(offset >= skb_headlen(skb)))

		goto out;



	csum = skb_checksum(skb, offset, skb->len - offset, 0);



	offset += skb->csum_offset;

	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));

	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb)))

		goto out;



	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));

	if (ret)