From 03606895cd98c0a628b17324fd7b5ff15db7e3cd Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 23 Feb 2012 10:55:02 +0000 Subject: ipsec: be careful of non existing mac headers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Niccolo Belli reported ipsec crashes in case we handle a frame without mac header (atm in his case) Before copying mac header, better make sure it is present. Bugzilla reference: https://bugzilla.kernel.org/show_bug.cgi?id=42809 Reported-by: Niccolò Belli Tested-by: Niccolò Belli Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/skbuff.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 50db9b04a552..ae86adee3746 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1465,6 +1465,16 @@ static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) } #endif /* NET_SKBUFF_DATA_USES_OFFSET */ +static inline void skb_mac_header_rebuild(struct sk_buff *skb) +{ + if (skb_mac_header_was_set(skb)) { + const unsigned char *old_mac = skb_mac_header(skb); + + skb_set_mac_header(skb, -skb->mac_len); + memmove(skb_mac_header(skb), old_mac, skb->mac_len); + } +} + static inline int skb_checksum_start_offset(const struct sk_buff *skb) { return skb->csum_start - skb_headroom(skb); -- cgit v1.2.3