From e582615ad33dbd39623084a02e95567b116e1eea Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 15 Jun 2016 06:24:00 -0700 Subject: gre: fix error handler 1) gre_parse_header() can be called from gre_err() At this point transport header points to ICMP header, not the inner header. 2) We can not really change transport header as ipgre_err() will later assume transport header still points to ICMP header (using icmp_hdr()) 3) pskb_may_pull() logic in gre_parse_header() really works if we are interested at zone pointed by skb->data 4) As Jiri explained in commit b7f8fe251e46 ("gre: do not pull header in ICMP error processing") we should not pull headers in error handler. So this fix : A) changes gre_parse_header() to use skb->data instead of skb_transport_header() B) Adds a nhs parameter to gre_parse_header() so that we can skip the not pulled IP header from error path. This offset is 0 for normal receive path. C) remove obsolete IPV6 includes Signed-off-by: Eric Dumazet Cc: Tom Herbert Cc: Maciej Żenczykowski Cc: Jiri Benc Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'net/ipv4/ip_gre.c') diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 07c5cf1838d8..1d000af7f561 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -49,12 +49,6 @@ #include #include -#if IS_ENABLED(CONFIG_IPV6) -#include -#include -#include -#endif - /* Problems & solutions -------------------- @@ -217,12 +211,14 @@ static void gre_err(struct sk_buff *skb, u32 info) * by themselves??? */ + const struct iphdr *iph = (struct iphdr *)skb->data; const int type = icmp_hdr(skb)->type; const int code = icmp_hdr(skb)->code; struct tnl_ptk_info tpi; bool csum_err = false; - if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP)) < 0) { + if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), + iph->ihl * 4) < 0) { if (!csum_err) /* ignore csum errors. */ return; } @@ -338,7 +334,7 @@ static int gre_rcv(struct sk_buff *skb) } #endif - hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP)); + hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0); if (hdr_len < 0) goto drop; -- cgit v1.2.3-55-g7522