Re: [PATCH V3] audit: normalize NETFILTER_PKT

On 2017-02-28 17:22, Paul Moore wrote: > On Sun, Feb 26, 2017 at 3:49 PM, Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > > Eliminate flipping in and out of message fields, dropping fields in the process. > > > > Sample raw message format IPv4 UDP: > > type=NETFILTER_PKT msg=audit(1487874761.386:228): mark=0xae8a2732 saddr=127.0.0.1 daddr=127.0.0.1 proto=17^] > > Sample raw message format IPv6 ICMP6: > > type=NETFILTER_PKT msg=audit(1487874761.381:227): mark=0x223894b7 saddr=::1 daddr=::1 proto=58^] > > > > Issue: https://github.com/linux-audit/audit-kernel/issues/11 > > Test case: https://github.com/linux-audit/audit-testsuite/issues/43 > > > > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; > > --- > > net/netfilter/xt_AUDIT.c | 122 ++++++++++----------------------------------- > > 1 files changed, 27 insertions(+), 95 deletions(-) > > > > diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c > > index 4973cbd..945fa29 100644 > > --- a/net/netfilter/xt_AUDIT.c > > +++ b/net/netfilter/xt_AUDIT.c > > @@ -31,146 +31,78 @@ MODULE_ALIAS("ip6t_AUDIT"); > > ... > > > -static void audit_ip4(struct audit_buffer *ab, struct sk_buff *skb) > > +static bool audit_ip4(struct audit_buffer *ab, struct sk_buff *skb) > > { > > struct iphdr _iph; > > const struct iphdr *ih; > > > > ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); > > It seems like we should be using skb_network_offset(skb) instead of 0 > above, yes? Granted, this isn't new, but let's fix it. Yes, I agree. How does this even work now? Maybe the MAC header hasn't been added yet (or has already been processed and stripped off) so that skb->data is already pointing at the network header and hence has an offset of 0. Can you be more explicit and elaborate to say if this what you were thinking?