From db07dd613e461df93dde7902c6505629bf0734e9 Mon Sep 17 00:00:00 2001 From: David Kilzer Date: Fri, 12 Feb 2016 09:58:29 -0800 Subject: [PATCH] Bug 758588: Heap-based buffer overread in xmlParserPrintFileContextInternal * parser.c: (xmlParseEndTag2): Add bounds checks before dereferencing ctxt->input->cur past the end of the buffer, or incrementing the pointer past the end of the buffer. * result/errors/758588.xml: Add test result. * result/errors/758588.xml.err: Ditto. * result/errors/758588.xml.str: Ditto. * test/errors/758588.xml: Add regression test. Upstream-Status: Backport CVE: CVE-2016-1838 Signed-off-by: Armin Kuster --- parser.c | 8 ++++++-- result/errors/758588.xml | 0 result/errors/758588.xml.err | 9 +++++++++ result/errors/758588.xml.str | 10 ++++++++++ test/errors/758588.xml | 1 + 5 files changed, 26 insertions(+), 2 deletions(-) create mode 100644 result/errors/758588.xml create mode 100644 result/errors/758588.xml.err create mode 100644 result/errors/758588.xml.str create mode 100644 test/errors/758588.xml Index: libxml2-2.9.2/parser.c =================================================================== --- libxml2-2.9.2.orig/parser.c +++ libxml2-2.9.2/parser.c @@ -9837,6 +9837,7 @@ static void xmlParseEndTag2(xmlParserCtxtPtr ctxt, const xmlChar *prefix, const xmlChar *URI, int line, int nsNr, int tlen) { const xmlChar *name; + size_t curLength; GROW; if ((RAW != '<') || (NXT(1) != '/')) { @@ -9845,8 +9846,11 @@ xmlParseEndTag2(xmlParserCtxtPtr ctxt, c } SKIP(2); - if ((tlen > 0) && (xmlStrncmp(ctxt->input->cur, ctxt->name, tlen) == 0)) { - if (ctxt->input->cur[tlen] == '>') { + curLength = ctxt->input->end - ctxt->input->cur; + if ((tlen > 0) && (curLength >= (size_t)tlen) && + (xmlStrncmp(ctxt->input->cur, ctxt->name, tlen) == 0)) { + if ((curLength >= (size_t)(tlen + 1)) && + (ctxt->input->cur[tlen] == '>')) { ctxt->input->cur += tlen + 1; ctxt->input->col += tlen + 1; goto done; Index: libxml2-2.9.2/result/errors/758588.xml.err =================================================================== --- /dev/null +++ libxml2-2.9.2/result/errors/758588.xml.err @@ -0,0 +1,9 @@ +./test/errors/758588.xml:1: namespace error : Namespace prefix 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on a is not defined +63472597946867209384634725979468672093846347259794686720938463472597946867261d:a + ^ +./test/errors/758588.xml:1: parser error : expected '>' +2597946867209384634725979468672093846347259794686720938463472597946867261d:a>' +2597946867209384634725979468672093846347259794686720938463472597946867261d:a>