From 3d6a43155c702bce0e7e2a93a67247b5ce3946a5 Mon Sep 17 00:00:00 2001
From: Tianjie Xu <xunchang@google.com>
Date: Wed, 5 Apr 2017 14:46:27 -0700
Subject: [PATCH] Fix out of bound read in libziparchive
We should check the boundary of central directory before checking its
signature. Swap the order of these two checks.
Bug: 36392138
Test: libziparchive doesn't read the signature after boundary check fails.
Change-Id: Ie89f709bb2d1ccb647116fb7ccb1e23c943e5ab8
(cherry picked from commit 74464a1361562d4042a67c5d66bfcf396ee7e59c)
(cherry picked from commit d9fd1863f46d5185eaaebc0803ee9c5da3ef110b)
---
libziparchive/zip_archive.cc | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index 986ee7208f..49097ce9b0 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -386,6 +386,14 @@ static int32_t ParseZipArchive(ZipArchive* archive) {
const uint8_t* const cd_end = cd_ptr + cd_length;
const uint8_t* ptr = cd_ptr;
for (uint16_t i = 0; i < num_entries; i++) {
+ if (ptr > cd_end - sizeof(CentralDirectoryRecord)) {
+ ALOGW("Zip: ran off the end (at %" PRIu16 ")", i);
+#if defined(__ANDROID__)
+ android_errorWriteLog(0x534e4554, "36392138");
+#endif
+ return -1;
+ }
+
const CentralDirectoryRecord* cdr =
reinterpret_cast<const CentralDirectoryRecord*>(ptr);
if (cdr->record_signature != CentralDirectoryRecord::kSignature) {
@@ -393,11 +401,6 @@ static int32_t ParseZipArchive(ZipArchive* archive) {
return -1;
}
- if (ptr + sizeof(CentralDirectoryRecord) > cd_end) {
- ALOGW("Zip: ran off the end (at %" PRIu16 ")", i);
- return -1;
- }
-
const off64_t local_header_offset = cdr->local_file_header_offset;
if (local_header_offset >= archive->directory_offset) {
ALOGW("Zip: bad LFH offset %" PRId64 " at entry %" PRIu16,
--
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