From: Eric Dumazet Date: Tue, 5 Nov 2024 17:44:01 +0000 (+0000) Subject: net: add debug check in skb_reset_transport_header() X-Git-Tag: v6.13-rc1~135^2~120^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ae50ea52bdd77eabd8f3c4630c1b03c3373f61a5;p=thirdparty%2Fkernel%2Flinux.git net: add debug check in skb_reset_transport_header() Make sure (skb->data - skb->head) can fit in skb->transport_header This needs CONFIG_DEBUG_NET=y. Signed-off-by: Eric Dumazet Reviewed-by: Joe Damato Reviewed-by: Xuan Zhuo Link: https://patch.msgid.link/20241105174403.850330-6-edumazet@google.com Signed-off-by: Jakub Kicinski --- diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 32a7d8a65b9f8..f76524844e7ed 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3007,7 +3007,10 @@ static inline unsigned char *skb_transport_header(const struct sk_buff *skb) static inline void skb_reset_transport_header(struct sk_buff *skb) { - skb->transport_header = skb->data - skb->head; + long offset = skb->data - skb->head; + + DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->transport_header))offset); + skb->transport_header = offset; } static inline void skb_set_transport_header(struct sk_buff *skb,