Commit 3b6167e9 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

net: add debug check in skb_reset_mac_header() 



Make sure (skb->data - skb->head) can fit in skb->mac_header

This needs CONFIG_DEBUG_NET=y.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarJoe Damato <jdamato@fastly.com>
Reviewed-by: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://patch.msgid.link/20241105174403.850330-8-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 305ae87d

include/linux/skbuff.h

+4 −1
Original line number Diff line number Diff line
@@ -3063,7 +3063,10 @@ static inline void skb_unset_mac_header(struct sk_buff *skb) 


static inline void skb_reset_mac_header(struct sk_buff *skb)

{

	skb->mac_header = skb->data - skb->head;

	long offset = skb->data - skb->head;



	DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->mac_header))offset);

	skb->mac_header = offset;

}



static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)