a7y18lte-ubports/android_kernel_samsung_universal7885
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flow_dissector: fix ipv6 dst, hop-by-hop and routing ext hdrs

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__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: 6a74fcf426 ("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>
This commit is contained in:
Eric Dumazet 2015-06-12 19:31:32 -07:00 committed by David S. Miller
parent 5b173cf927
commit 1e98a0f08a
2 changed files with 9 additions and 6 deletions
include/linux
skbuff.h
net/core
flow_dissector.c

9
include/linux/skbuff.h
View File

@ -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 skb_checksum(const struct sk_buff *skb, int offset, int len,
__wsum csum); __wsum csum);
static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset, static inline void * __must_check
int len, void *data, int hlen, void *buffer) __skb_header_pointer(const struct sk_buff *skb, int offset,
int len, void *data, int hlen, void *buffer)
{ {
if (hlen - offset >= len) if (hlen - offset >= len)
return data + offset; return data + offset;
@ -2756,8 +2757,8 @@ static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset,
return buffer; return buffer;
} }
static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, static inline void * __must_check
int len, void *buffer) skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
{ {
return __skb_header_pointer(skb, offset, len, skb->data, return __skb_header_pointer(skb, offset, len, skb->data,
skb_headlen(skb), buffer); skb_headlen(skb), buffer);

6
net/core/flow_dissector.c
View File

@ -394,9 +394,11 @@ ip_proto_again:
opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr), opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
data, hlen, &_opthdr); data, hlen, &_opthdr);
if (!opthdr)
return false;
ip_proto = _opthdr[0]; ip_proto = opthdr[0];
nhoff += (_opthdr[1] + 1) << 3; nhoff += (opthdr[1] + 1) << 3;
goto ip_proto_again; goto ip_proto_again;
} }