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| author | Jiri Benc <jbenc@redhat.com> | 2016-04-29 23:31:32 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-05-02 06:19:58 +0200 |
| commit | b7f8fe251e4609e2a437bd2c2dea01e61db6849c (patch) | |
| tree | 2c1fec745c1ddb827e787b68e16b8ca987874aeb /net/ipv4/ip_gre.c | |
| parent | net: Implement net_dbg_ratelimited() for CONFIG_DYNAMIC_DEBUG case (diff) | |
| download | linux-b7f8fe251e4609e2a437bd2c2dea01e61db6849c.tar.xz linux-b7f8fe251e4609e2a437bd2c2dea01e61db6849c.zip | |
gre: do not pull header in ICMP error processing
iptunnel_pull_header expects that IP header was already pulled; with this
expectation, it pulls the tunnel header. This is not true in gre_err.
Furthermore, ipv4_update_pmtu and ipv4_redirect expect that skb->data points
to the IP header.
We cannot pull the tunnel header in this path. It's just a matter of not
calling iptunnel_pull_header - we don't need any of its effects.
Fixes: bda7bb463436 ("gre: Allow multiple protocol listener for gre protocol.")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_gre.c')
| -rw-r--r-- | net/ipv4/ip_gre.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index f502d34bcb40..205a2b8a5a84 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -179,6 +179,7 @@ static __be16 tnl_flags_to_gre_flags(__be16 tflags) return flags; } +/* Fills in tpi and returns header length to be pulled. */ static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, bool *csum_err) { @@ -238,7 +239,7 @@ static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, return -EINVAL; } } - return iptunnel_pull_header(skb, hdr_len, tpi->proto, false); + return hdr_len; } static void ipgre_err(struct sk_buff *skb, u32 info, @@ -341,7 +342,7 @@ static void gre_err(struct sk_buff *skb, u32 info) struct tnl_ptk_info tpi; bool csum_err = false; - if (parse_gre_header(skb, &tpi, &csum_err)) { + if (parse_gre_header(skb, &tpi, &csum_err) < 0) { if (!csum_err) /* ignore csum errors. */ return; } @@ -419,6 +420,7 @@ static int gre_rcv(struct sk_buff *skb) { struct tnl_ptk_info tpi; bool csum_err = false; + int hdr_len; #ifdef CONFIG_NET_IPGRE_BROADCAST if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { @@ -428,7 +430,10 @@ static int gre_rcv(struct sk_buff *skb) } #endif - if (parse_gre_header(skb, &tpi, &csum_err) < 0) + hdr_len = parse_gre_header(skb, &tpi, &csum_err); + if (hdr_len < 0) + goto drop; + if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false) < 0) goto drop; if (ipgre_rcv(skb, &tpi) == PACKET_RCVD) |