68 lines
2.8 KiB
Diff
68 lines
2.8 KiB
Diff
Fix CVE-2016-1541 (buffer overflow zip_read_mac_metadata)
|
|
|
|
Taken from upstream source repository:
|
|
https://github.com/libarchive/libarchive/commit/d0331e8e5b05b475f20b1f3101fe1ad772d7e7e7
|
|
|
|
When reading OS X metadata entries in Zip archives that were stored
|
|
without compression, libarchive would use the uncompressed entry size
|
|
to allocate a buffer but would use the compressed entry size to limit
|
|
the amount of data copied into that buffer. Since the compressed
|
|
and uncompressed sizes are provided by data in the archive itself,
|
|
an attacker could manipulate these values to write data beyond
|
|
the end of the allocated buffer.
|
|
|
|
This fix provides three new checks to guard against such
|
|
manipulation and to make libarchive generally more robust when
|
|
handling this type of entry:
|
|
1. If an OS X metadata entry is stored without compression,
|
|
abort the entire archive if the compressed and uncompressed
|
|
data sizes do not match.
|
|
2. When sanity-checking the size of an OS X metadata entry,
|
|
abort this entry if either the compressed or uncompressed
|
|
size is larger than 4MB.
|
|
3. When copying data into the allocated buffer, check the copy
|
|
size against both the compressed entry size and uncompressed
|
|
entry size.
|
|
---
|
|
libarchive/archive_read_support_format_zip.c | 13 +++++++++++++
|
|
1 file changed, 13 insertions(+)
|
|
|
|
diff --git a/libarchive/archive_read_support_format_zip.c b/libarchive/archive_read_support_format_zip.c
|
|
index 0f8262c..0a0be96 100644
|
|
--- a/libarchive/archive_read_support_format_zip.c
|
|
+++ b/libarchive/archive_read_support_format_zip.c
|
|
@@ -2778,6 +2778,11 @@ zip_read_mac_metadata(struct archive_read *a, struct archive_entry *entry,
|
|
|
|
switch(rsrc->compression) {
|
|
case 0: /* No compression. */
|
|
+ if (rsrc->uncompressed_size != rsrc->compressed_size) {
|
|
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
|
|
+ "Malformed OS X metadata entry: inconsistent size");
|
|
+ return (ARCHIVE_FATAL);
|
|
+ }
|
|
#ifdef HAVE_ZLIB_H
|
|
case 8: /* Deflate compression. */
|
|
#endif
|
|
@@ -2798,6 +2803,12 @@ zip_read_mac_metadata(struct archive_read *a, struct archive_entry *entry,
|
|
(intmax_t)rsrc->uncompressed_size);
|
|
return (ARCHIVE_WARN);
|
|
}
|
|
+ if (rsrc->compressed_size > (4 * 1024 * 1024)) {
|
|
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
|
|
+ "Mac metadata is too large: %jd > 4M bytes",
|
|
+ (intmax_t)rsrc->compressed_size);
|
|
+ return (ARCHIVE_WARN);
|
|
+ }
|
|
|
|
metadata = malloc((size_t)rsrc->uncompressed_size);
|
|
if (metadata == NULL) {
|
|
@@ -2836,6 +2847,8 @@ zip_read_mac_metadata(struct archive_read *a, struct archive_entry *entry,
|
|
bytes_avail = remaining_bytes;
|
|
switch(rsrc->compression) {
|
|
case 0: /* No compression. */
|
|
+ if ((size_t)bytes_avail > metadata_bytes)
|
|
+ bytes_avail = metadata_bytes;
|
|
memcpy(mp, p, bytes_avail);
|
|
bytes_used = (size_t)bytes_avail;
|
|
metadata_bytes -= bytes_used;
|