From: "David S. Miller" <davem@redhat.com>
To: Pekka Savola <pekkas@netcore.fi>
Cc: "Maciej 'Agaran' Pijanka" <agaran@agaran.6bone.pl>,
NetDevel List <netdev@oss.sgi.com>, <kuznet@ms2.inr.ac.ru>,
linux-kernel@vger.kernel.org
Subject: [PATCH] (was Re: 2.4.4 & IPv6 oopses)
Date: Fri, 4 May 2001 18:46:12 -0700 (PDT) [thread overview]
Message-ID: <15091.23396.515412.928664@pizda.ninka.net> (raw)
In-Reply-To: <Pine.LNX.4.33.0105041709450.31252-100000@netcore.fi>
In-Reply-To: <Pine.LNX.4.21.0105041357150.17065-100000@kepler.agaran.6bone.pl> <Pine.LNX.4.33.0105041709450.31252-100000@netcore.fi>
Pekka Savola writes:
> struct in6_addr *saddr = NULL;
> [...]
> if (skb && ipv6_chk_addr(&skb->nh.ipv6h->saddr, dev))
> saddr = &skb->nh.ipv6h->saddr;
> [...]
> ndisc_send_ns(dev, neigh, target, target, saddr);
> [...]
> This check apparently fails? and saddr is left null.
Yes, it can fail, and this is normal. The problem is in
ndisc_send_ns().
> in ndisc_send_ns, NULL saddr is checked:
>
> send_llinfo = dev->addr_len && ipv6_addr_type(saddr) != IPV6_ADDR_ANY;
>
> which make a null ptr dereference. send_llinfo check was added recently
> to fix RFC incompliancy a week or so ago.
A few lines later we setup saddr properly if it is NULL, what we need
to do is either:
1) Move that "if (saddr == NULL)" code block up above the send_llinfo
check.
I think this would break the thing the send_llinfo check
was meant to fix, but I can't be sure.
2) Just check for NULL saddr in the send_llinfo check and if NULL
then send_llinfo is set to zero.
For now, I've put solution #2 into my tree, patch attached below.
--- linux/net/ipv6/ndisc.c.~1~ Thu May 3 00:01:10 2001
+++ linux/net/ipv6/ndisc.c Fri May 4 18:44:54 2001
@@ -382,7 +382,7 @@
int send_llinfo;
len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
- send_llinfo = dev->addr_len && ipv6_addr_type(saddr) != IPV6_ADDR_ANY;
+ send_llinfo = dev->addr_len && saddr && ipv6_addr_type(saddr) != IPV6_ADDR_ANY;
if (send_llinfo)
len += NDISC_OPT_SPACE(dev->addr_len);
next parent reply other threads:[~2001-05-05 1:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.33.0105041709450.31252-100000@netcore.fi>
[not found] ` <Pine.LNX.4.21.0105041357150.17065-100000@kepler.agaran.6bone.pl>
2001-05-05 1:46 ` David S. Miller [this message]
2001-05-05 6:32 ` [PATCH] (was Re: 2.4.4 & IPv6 oopses) Cliff Albert
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