Blame SOURCES/libxml2-2.9.7-CVE-2020-24977.patch

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From 50f06b3efb638efb0abd95dc62dca05ae67882c2 Mon Sep 17 00:00:00 2001
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From: Nick Wellnhofer <wellnhofer@aevum.de>
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Date: Fri, 7 Aug 2020 21:54:27 +0200
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Subject: [PATCH] Fix out-of-bounds read with 'xmllint --htmlout'
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Make sure that truncated UTF-8 sequences don't cause an out-of-bounds
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array access.
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Thanks to @SuhwanSong and the Agency for Defense Development (ADD) for
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the report.
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Fixes #178.
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---
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 xmllint.c | 6 ++++++
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 1 file changed, 6 insertions(+)
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diff --git a/xmllint.c b/xmllint.c
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index f6a8e4636..c647486f3 100644
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--- a/xmllint.c
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+++ b/xmllint.c
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@@ -528,6 +528,12 @@ static void
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 xmlHTMLEncodeSend(void) {
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     char *result;
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+    /*
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+     * xmlEncodeEntitiesReentrant assumes valid UTF-8, but the buffer might
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+     * end with a truncated UTF-8 sequence. This is a hack to at least avoid
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+     * an out-of-bounds read.
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+     */
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+    memset(&buffer[sizeof(buffer)-4], 0, 4);
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     result = (char *) xmlEncodeEntitiesReentrant(NULL, BAD_CAST buffer);
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     if (result) {
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 	xmlGenericError(xmlGenericErrorContext, "%s", result);
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-- 
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GitLab
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