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authorEric Dumazet <edumazet@google.com>2016-06-15 16:24:00 +0300
committerDavid S. Miller <davem@davemloft.net>2016-06-16 08:15:21 +0300
commite582615ad33dbd39623084a02e95567b116e1eea (patch)
tree16f807a602e42f6918f9991b0725bc6e26847025 /net/ipv4/gre_demux.c
parentdaddef76c3deaaa7922f9d7b18edbf0a061215c3 (diff)
downloadlinux-e582615ad33dbd39623084a02e95567b116e1eea.tar.xz
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 <edumazet@google.com> Cc: Tom Herbert <tom@herbertland.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/gre_demux.c')
-rw-r--r--net/ipv4/gre_demux.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index 4c39f4fd332a..de1d119a4497 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -62,26 +62,26 @@ EXPORT_SYMBOL_GPL(gre_del_protocol);
/* Fills in tpi and returns header length to be pulled. */
int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
- bool *csum_err, __be16 proto)
+ bool *csum_err, __be16 proto, int nhs)
{
const struct gre_base_hdr *greh;
__be32 *options;
int hdr_len;
- if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
+ if (unlikely(!pskb_may_pull(skb, nhs + sizeof(struct gre_base_hdr))))
return -EINVAL;
- greh = (struct gre_base_hdr *)skb_transport_header(skb);
+ greh = (struct gre_base_hdr *)(skb->data + nhs);
if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
return -EINVAL;
tpi->flags = gre_flags_to_tnl_flags(greh->flags);
hdr_len = gre_calc_hlen(tpi->flags);
- if (!pskb_may_pull(skb, hdr_len))
+ if (!pskb_may_pull(skb, nhs + hdr_len))
return -EINVAL;
- greh = (struct gre_base_hdr *)skb_transport_header(skb);
+ greh = (struct gre_base_hdr *)(skb->data + nhs);
tpi->proto = greh->protocol;
options = (__be32 *)(greh + 1);