Fiz /usr/bin/unzip: A bug deep in libarchive's read-ahead logic

(incorrect handling of zero-length reads before the copy buffer is
allocated) is masked by the iso9660 taster.  Tar and cpio both enable
that taster so were protected from the bug; unzip is susceptible.

This both fixes the bug and updates the test harness to exercise
this case.

Submitted by: Ed Schouten diagnosed the bug and drafted a patch
MFC after: 7 days
This commit is contained in:
Tim Kientzle 2009-09-08 05:02:41 +00:00
parent 26baaf0169
commit 466017cf76
2 changed files with 6 additions and 3 deletions

View File

@ -928,9 +928,12 @@ __archive_read_filter_ahead(struct archive_read_filter *filter,
for (;;) {
/*
* If we can satisfy from the copy buffer, we're done.
* If we can satisfy from the copy buffer (and the
* copy buffer isn't empty), we're done. In particular,
* note that min == 0 is a perfectly well-defined
* request.
*/
if (filter->avail >= min) {
if (filter->avail >= min && filter->avail > 0) {
if (avail != NULL)
*avail = filter->avail;
return (filter->next);

View File

@ -36,7 +36,7 @@ test_compat_zip_1(void)
assert((a = archive_read_new()) != NULL);
assertEqualIntA(a, ARCHIVE_OK, archive_read_support_compression_all(a));
assertEqualIntA(a, ARCHIVE_OK, archive_read_support_format_all(a));
assertEqualIntA(a, ARCHIVE_OK, archive_read_support_format_zip(a));
extract_reference_file(name);
assertEqualIntA(a, ARCHIVE_OK, archive_read_open_filename(a, name, 10240));