libxml2/Reset-HTML-parser-input-before-reporting-error.patch
zou_lin77 e81785b5f3 Fix more quadratic runtime issues in HTML push parse
Fix reset HTML parser input before reporting error
2020-08-28 18:30:14 +08:00

50 lines
1.6 KiB
Diff

From 3f18e7486d5feb8ae41911ce3c122e05641a4c3d Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Sat, 11 Jul 2020 14:34:57 +0200
Subject: [PATCH] Reset HTML parser input before reporting error
Avoid use-after-free, similar to 13ba5b61. Also make sure that
xmlBufSetInputBaseCur sets valid pointers in case of buffer errors.
Found by OSS-Fuzz.
diff --git a/HTMLparser.c b/HTMLparser.c
index 9b12dd1..1dea794 100644
--- a/HTMLparser.c
+++ b/HTMLparser.c
@@ -6150,12 +6150,12 @@ htmlParseChunk(htmlParserCtxtPtr ctxt, const char *chunk, int size,
int res;
res = xmlParserInputBufferPush(ctxt->input->buf, size, chunk);
+ xmlBufSetInputBaseCur(ctxt->input->buf->buffer, ctxt->input, base, cur);
if (res < 0) {
ctxt->errNo = XML_PARSER_EOF;
ctxt->disableSAX = 1;
return (XML_PARSER_EOF);
}
- xmlBufSetInputBaseCur(ctxt->input->buf->buffer, ctxt->input, base, cur);
#ifdef DEBUG_PUSH
xmlGenericError(xmlGenericErrorContext, "HPP: pushed %d\n", size);
#endif
diff --git a/buf.c b/buf.c
index 8ad18a1..24368d3 100644
--- a/buf.c
+++ b/buf.c
@@ -1334,8 +1334,12 @@ xmlBufGetInputBase(xmlBufPtr buf, xmlParserInputPtr input) {
int
xmlBufSetInputBaseCur(xmlBufPtr buf, xmlParserInputPtr input,
size_t base, size_t cur) {
- if ((input == NULL) || (buf == NULL) || (buf->error))
+ if (input == NULL)
+ return(-1);
+ if ((buf == NULL) || (buf->error)) {
+ input->base = input->cur = input->end = BAD_CAST "";
return(-1);
+ }
CHECK_COMPAT(buf)
input->base = &buf->content[base];
input->cur = input->base + cur;
--
1.8.3.1