Messages in this thread |  | | | Date | Tue, 2 May 2006 16:01:02 +0200 | | From | Ingo Molnar <> | | Subject | Re: [netfilter-core] Re: [lockup] 2.6.17-rc3: netfilter/sctp: lockup in sctp_new(), do_basic_checks() |
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* Patrick McHardy <kaber@trash.net> wrote:
> Ingo Molnar wrote: > > thinking about it, what prevents the SCTP chunk's len field from being > > zero, and thus causing an infinite loop in for_each_sctp_chunk()? The > > patch below should fix that. > > > > Ingo > > > > ---- > > From: Ingo Molnar <mingo@elte.hu> > > > > fix infinite loop in the SCTP-netfilter code: check SCTP chunk size to > > guarantee progress of for_each_sctp_chunk(). (all other uses of > > for_each_sctp_chunk() are preceded by do_basic_checks(), so this fix > > should be complete.) > > > > Signed-off-by: Ingo Molnar <mingo@elte.hu> > > > > Index: linux/net/ipv4/netfilter/ip_conntrack_proto_sctp.c > > =================================================================== > > --- linux.orig/net/ipv4/netfilter/ip_conntrack_proto_sctp.c > > +++ linux/net/ipv4/netfilter/ip_conntrack_proto_sctp.c > > @@ -227,6 +227,15 @@ static int do_basic_checks(struct ip_con > > flag = 0; > > > > for_each_sctp_chunk (skb, sch, _sch, offset, count) { > > + unsigned int len = (htons(sch->length) + 3) & ~3; > > + > > + /* > > + * Dont get into a loop with zero-sized or negative > > + * length values: > > + */ > > + if (!len || len >= skb->len) > > + goto fail; > > + > > I just came up with a similar fix :) I think I'm going to take my own > patch though because its IMO slightly nicer. Thanks anyway.
could you send your patch so that i can start using it instead of mine?
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