lkml.org 
[lkml]   [2001]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH] (was Re: 2.4.4 & IPv6 oopses)

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);




-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:52    [W:0.033 / U:2.712 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site