Messages in this thread | | | Subject | Re: [PATCH net] net: flow_dissector: fail on evil iph->ihl | From | Ben Hutchings <> | Date | Fri, 1 Nov 2013 16:29:27 +0000 |
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On Fri, 2013-11-01 at 15:01 +0800, Jason Wang wrote: > We don't validate iph->ihl which may lead a dead loop if we meet a IPIP > skb whose iph->ihl is zero. Fix this by failing immediately when iph->ihl > is evil (less than 5). > > This issue were introduced by commit ec5efe7946280d1e84603389a1030ccec0a767ae > (rps: support IPIP encapsulation).
It would be helpful to include the CVE ID here:
CVE-2013-4348
Ben.
> Cc: Eric Dumazet <edumazet@google.com> > Cc: Petr Matousek <pmatouse@redhat.com> > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Daniel Borkmann <dborkman@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > This patch is needed for stable. > --- > net/core/flow_dissector.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c > index 8d7d0dd..143b6fd 100644 > --- a/net/core/flow_dissector.c > +++ b/net/core/flow_dissector.c > @@ -40,7 +40,7 @@ again: > struct iphdr _iph; > ip: > iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); > - if (!iph) > + if (!iph || iph->ihl < 5) > return false; > > if (ip_is_fragment(iph))
-- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.
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