From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> The check makes sure that we can look at the ip header. We first need to check that the basic ip header (20 bytes) can be pulled before we look at the field that will teach us how long is the ip header. This is why there are two checks. The second check was wrong and smatch pointed that sizeof(ip_hdrlen(skb) - sizeof(*iphdr)) can't be right. Looking at the code again made me think that we really need ip_hdrlen(skb) since we want to make sure all the IP header is in the buffer header. This will allow us to set the transport offset and from there to look at the transport header (TCP / UDP). Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> Fixes: 2da4366f9e2c ("iwlwifi: mei: add the driver to allow cooperation with CSME") Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx> --- drivers/net/wireless/intel/iwlwifi/mei/net.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mei/net.c b/drivers/net/wireless/intel/iwlwifi/mei/net.c index 5f966af69720..468102a95e1b 100644 --- a/drivers/net/wireless/intel/iwlwifi/mei/net.c +++ b/drivers/net/wireless/intel/iwlwifi/mei/net.c @@ -195,8 +195,7 @@ static bool iwl_mei_rx_filter_ipv4(struct sk_buff *skb, bool match; if (!pskb_may_pull(skb, skb_network_offset(skb) + sizeof(*iphdr)) || - !pskb_may_pull(skb, skb_network_offset(skb) + - sizeof(ip_hdrlen(skb) - sizeof(*iphdr)))) + !pskb_may_pull(skb, skb_network_offset(skb) + ip_hdrlen(skb))) return false; iphdrlen = ip_hdrlen(skb); -- 2.34.1