From cfe8394e06f22847ecae0312bdd0b633b471b3f0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 5 Nov 2024 17:43:58 +0000 Subject: [PATCH] net: add debug check in skb_reset_inner_transport_header() Make sure (skb->data - skb->head) can fit in skb->inner_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/20241105174403.850330-3-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/linux/skbuff.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 5d8fefa71cac..75795568803c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2937,7 +2937,10 @@ static inline int skb_inner_transport_offset(const struct sk_buff *skb) static inline void skb_reset_inner_transport_header(struct sk_buff *skb) { - skb->inner_transport_header = skb->data - skb->head; + long offset = skb->data - skb->head; + + DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_transport_header))offset); + skb->inner_transport_header = offset; } static inline void skb_set_inner_transport_header(struct sk_buff *skb, -- 2.25.1