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@@ -0,0 +1,45 @@
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+From c602079e5b7ba998d1dd6cae4a305af80e6cba52 Mon Sep 17 00:00:00 2001
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+From: Gabor Juhos <[email protected]>
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+Date: Tue, 23 Mar 2010 08:35:27 +0100
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+Subject: [PATCH] Fix use-after-free bug in __dns_lookup.
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+
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+If the type of the first answer does not match with the requested type,
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+then the dotted name will be freed. If there are no further answers in
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+the DNS reply, this pointer will be used later on in the same function.
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+Additionally it is passed to the caller, and may cause strange behaviour.
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+
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+For example, the following busybox commands are triggering a segmentation
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+fault with uClibc 0.9.30.x
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+
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+ - nslookup ipv6.google.com
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+ - ping ipv6.google.com
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+ - wget http//ipv6.google.com/
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+
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+Signed-off-by: Gabor Juhos <[email protected]>
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+
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+---
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+
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+See https://dev.openwrt.org/ticket/6886 for a testcase
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+---
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+ libc/inet/resolv.c | 4 +---
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+ 1 files changed, 1 insertions(+), 3 deletions(-)
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+
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+diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c
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+index 0a6fd7a..e76f0aa 100644
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+--- a/libc/inet/resolv.c
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++++ b/libc/inet/resolv.c
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+@@ -1501,10 +1501,8 @@ int attribute_hidden __dns_lookup(const char *name,
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+ memcpy(a, &ma, sizeof(ma));
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+ if (a->atype != T_SIG && (NULL == a->buf || (type != T_A && type != T_AAAA)))
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+ break;
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+- if (a->atype != type) {
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+- free(a->dotted);
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++ if (a->atype != type)
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+ continue;
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+- }
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+ a->add_count = h.ancount - j - 1;
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+ if ((a->rdlength + sizeof(struct in_addr*)) * a->add_count > a->buflen)
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+ break;
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+--
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+1.5.3.2
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+
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Gabor Juhos