| From | Greg Kroah-Hartman <> | Subject | [ 052/133] ipv4: raw: fix icmp_filter() | Date | Thu, 11 Oct 2012 07:51:18 +0900 |
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3.5-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ Upstream commit ab43ed8b7490cb387782423ecf74aeee7237e591 ]
icmp_filter() should not modify its input, or else its caller would need to recompute ip_hdr() if skb->head is reallocated.
Use skb_header_pointer() instead of pskb_may_pull() and change the prototype to make clear both sk and skb are const.
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ipv4/raw.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
--- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -131,18 +131,20 @@ found: * 0 - deliver * 1 - block */ -static __inline__ int icmp_filter(struct sock *sk, struct sk_buff *skb) +static int icmp_filter(const struct sock *sk, const struct sk_buff *skb) { - int type; + struct icmphdr _hdr; + const struct icmphdr *hdr; - if (!pskb_may_pull(skb, sizeof(struct icmphdr))) + hdr = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_hdr), &_hdr); + if (!hdr) return 1; - type = icmp_hdr(skb)->type; - if (type < 32) { + if (hdr->type < 32) { __u32 data = raw_sk(sk)->filter.data; - return ((1 << type) & data) != 0; + return ((1U << hdr->type) & data) != 0; } /* Do not block unknown ICMP types */
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