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)
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index a17091f..8c2c559 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -580,6 +580,14 @@
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) {
@@ -587,11 +595,6 @@
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,