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authorEric Dumazet <edumazet@google.com>2015-06-12 19:31:32 -0700
committerDavid S. Miller <davem@davemloft.net>2015-06-12 21:58:49 -0700
commit1e98a0f08abddde87f0f93237f10629ecb4880ef (patch)
treed076e4b8b38b5cc82e865986ceb736585dca2374
parent5b173cf92729b02ff8207abd85bfcbbef3443b94 (diff)
flow_dissector: fix ipv6 dst, hop-by-hop and routing ext hdrs
__skb_header_pointer() returns a pointer that must be checked. Fixes infinite loop reported by Alexei, and add __must_check to catch these errors earlier. Fixes: 6a74fcf426f5 ("flow_dissector: add support for dst, hop-by-hop and routing ext hdrs") Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Tested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/skbuff.h9
-rw-r--r--net/core/flow_dissector.c6
2 files changed, 9 insertions, 6 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index cc612fc0a894..a7acc92aa668 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2743,8 +2743,9 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
__wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
__wsum csum);
-static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset,
- int len, void *data, int hlen, void *buffer)
+static inline void * __must_check
+__skb_header_pointer(const struct sk_buff *skb, int offset,
+ int len, void *data, int hlen, void *buffer)
{
if (hlen - offset >= len)
return data + offset;
@@ -2756,8 +2757,8 @@ static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset,
return buffer;
}
-static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
- int len, void *buffer)
+static inline void * __must_check
+skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
{
return __skb_header_pointer(skb, offset, len, skb->data,
skb_headlen(skb), buffer);
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 22e4dffa0c8b..476e5dda59e1 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -394,9 +394,11 @@ ip_proto_again:
opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
data, hlen, &_opthdr);
+ if (!opthdr)
+ return false;
- ip_proto = _opthdr[0];
- nhoff += (_opthdr[1] + 1) << 3;
+ ip_proto = opthdr[0];
+ nhoff += (opthdr[1] + 1) << 3;
goto ip_proto_again;
}

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