mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-11-30 19:37:31 +02:00
41 lines
1.3 KiB
Diff
41 lines
1.3 KiB
Diff
From c602079e5b7ba998d1dd6cae4a305af80e6cba52 Mon Sep 17 00:00:00 2001
|
|
From: Gabor Juhos <juhosg@openwrt.org>
|
|
Date: Tue, 23 Mar 2010 08:35:27 +0100
|
|
Subject: [PATCH] Fix use-after-free bug in __dns_lookup.
|
|
|
|
If the type of the first answer does not match with the requested type,
|
|
then the dotted name will be freed. If there are no further answers in
|
|
the DNS reply, this pointer will be used later on in the same function.
|
|
Additionally it is passed to the caller, and may cause strange behaviour.
|
|
|
|
For example, the following busybox commands are triggering a segmentation
|
|
fault with uClibc 0.9.30.x
|
|
|
|
- nslookup ipv6.google.com
|
|
- ping ipv6.google.com
|
|
- wget http//ipv6.google.com/
|
|
|
|
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
|
|
|
|
---
|
|
|
|
See https://dev.openwrt.org/ticket/6886 for a testcase
|
|
---
|
|
libc/inet/resolv.c | 4 +---
|
|
1 files changed, 1 insertions(+), 3 deletions(-)
|
|
|
|
--- a/libc/inet/resolv.c
|
|
+++ b/libc/inet/resolv.c
|
|
@@ -1517,10 +1517,8 @@ int attribute_hidden __dns_lookup(const
|
|
memcpy(a, &ma, sizeof(ma));
|
|
if (a->atype != T_SIG && (NULL == a->buf || (type != T_A && type != T_AAAA)))
|
|
break;
|
|
- if (a->atype != type) {
|
|
- free(a->dotted);
|
|
+ if (a->atype != type)
|
|
continue;
|
|
- }
|
|
a->add_count = h.ancount - j - 1;
|
|
if ((a->rdlength + sizeof(struct in_addr*)) * a->add_count > a->buflen)
|
|
break;
|