From 38eae571111db3b43ffdeb05487c9f60551906fb Mon Sep 17 00:00:00 2001 From: Pranjal Jumde Date: Mon, 7 Mar 2016 14:04:08 -0800 Subject: [PATCH] Heap use-after-free in xmlSAX2AttributeNs For https://bugzilla.gnome.org/show_bug.cgi?id=759020 * parser.c: (xmlParseStartTag2): Attribute strings are only valid if the base does not change, so add another check where the base may change. Make sure to set 'attvalue' to NULL after freeing it. * result/errors/759020.xml: Added. * result/errors/759020.xml.err: Added. * result/errors/759020.xml.str: Added. * test/errors/759020.xml: Added test case. --- parser.c | 12 ++++++++-- result/errors/759020.xml | 0 result/errors/759020.xml.err | 6 +++++ result/errors/759020.xml.str | 7 ++++++ test/errors/759020.xml | 46 ++++++++++++++++++++++++++++++++++++ 5 files changed, 69 insertions(+), 2 deletions(-) create mode 100644 result/errors/759020.xml create mode 100644 result/errors/759020.xml.err create mode 100644 result/errors/759020.xml.str create mode 100644 test/errors/759020.xml diff --git a/parser.c b/parser.c index 15c606f0..7aba6a9b 100644 --- a/parser.c +++ b/parser.c @@ -9488,7 +9488,10 @@ reparse: else if (nsPush(ctxt, NULL, URL) > 0) nbNs++; skip_default_ns: - if (alloc != 0) xmlFree(attvalue); + if ((attvalue != NULL) && (alloc != 0)) { + xmlFree(attvalue); + attvalue = NULL; + } if ((RAW == '>') || (((RAW == '/') && (NXT(1) == '>')))) break; if (!IS_BLANK_CH(RAW)) { @@ -9497,6 +9500,8 @@ skip_default_ns: break; } SKIP_BLANKS; + if ((ctxt->input->base != base) || (inputNr != ctxt->inputNr)) + goto base_changed; continue; } if (aprefix == ctxt->str_xmlns) { @@ -9568,7 +9573,10 @@ skip_default_ns: else if (nsPush(ctxt, attname, URL) > 0) nbNs++; skip_ns: - if (alloc != 0) xmlFree(attvalue); + if ((attvalue != NULL) && (alloc != 0)) { + xmlFree(attvalue); + attvalue = NULL; + } if ((RAW == '>') || (((RAW == '/') && (NXT(1) == '>')))) break; if (!IS_BLANK_CH(RAW)) { diff --git a/result/errors/759020.xml b/result/errors/759020.xml new file mode 100644 index 00000000..e69de29b diff --git a/result/errors/759020.xml.err b/result/errors/759020.xml.err new file mode 100644 index 00000000..a0d30517 --- /dev/null +++ b/result/errors/759020.xml.err @@ -0,0 +1,6 @@ +./test/errors/759020.xml:3: namespace warning : xmlns: URI 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 is not absolute +0000000000000000000000000000000000000000000000000000000000000000000000000000000' + ^ +./test/errors/759020.xml:46: parser error : Couldn't find end of Start Tag s00 line 2 + + ^ diff --git a/result/errors/759020.xml.str b/result/errors/759020.xml.str new file mode 100644 index 00000000..998d6d2f --- /dev/null +++ b/result/errors/759020.xml.str @@ -0,0 +1,7 @@ +./test/errors/759020.xml:3: namespace warning : xmlns: URI 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 is not absolute +0000000000000000000000000000000000000000000000000000000000000000000000000000000' + ^ +./test/errors/759020.xml:46: parser error : Couldn't find end of Start Tag s00 + + ^ +./test/errors/759020.xml : failed to parse diff --git a/test/errors/759020.xml b/test/errors/759020.xml new file mode 100644 index 00000000..db232756 --- /dev/null +++ b/test/errors/759020.xml @@ -0,0 +1,46 @@ + +