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authorDenys Vlasenko <vda.linux@googlemail.com>2013-07-21 00:31:08 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2013-07-21 00:31:08 (GMT)
commit26cd90c7fd32f2ef252acb146f8b9152e55346ec (patch)
treeb5a2a93c13d44eb91c94979f0aa74815bd740b5a
parent1390a010b60cbb5adad4e4c56a3613122b4298c6 (diff)
downloadbusybox-26cd90c7fd32f2ef252acb146f8b9152e55346ec.tar.gz
busybox-26cd90c7fd32f2ef252acb146f8b9152e55346ec.tar.bz2
unzip: survive lack of CDF on non-streaming zip files
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--archival/unzip.c55
1 files changed, 39 insertions, 16 deletions
diff --git a/archival/unzip.c b/archival/unzip.c
index c250d75..673e5fe 100644
--- a/archival/unzip.c
+++ b/archival/unzip.c
@@ -172,6 +172,9 @@ enum { zip_fd = 3 };
*/
#define PEEK_FROM_END (64*1024)
+/* This value means that we failed to find CDF */
+#define BAD_CDF_OFFSET ((uint32_t)0xffffffff)
+
/* NB: does not preserve file position! */
static uint32_t find_cdf_offset(void)
{
@@ -187,6 +190,7 @@ static uint32_t find_cdf_offset(void)
xlseek(zip_fd, end, SEEK_SET);
full_read(zip_fd, buf, PEEK_FROM_END);
+ cde_header.formatted.cdf_offset = BAD_CDF_OFFSET;
p = buf;
while (p <= buf + PEEK_FROM_END - CDE_HEADER_LEN - 4) {
if (*p != 'P') {
@@ -202,11 +206,17 @@ static uint32_t find_cdf_offset(void)
/* we found CDE! */
memcpy(cde_header.raw, p + 1, CDE_HEADER_LEN);
FIX_ENDIANNESS_CDE(cde_header);
- free(buf);
- return cde_header.formatted.cdf_offset;
+ /*
+ * I've seen .ZIP files with seemingly valid CDEs
+ * where cdf_offset points past EOF - ??
+ * Ignore such CDEs:
+ */
+ if (cde_header.formatted.cdf_offset < end + (p - buf))
+ break;
+ cde_header.formatted.cdf_offset = BAD_CDF_OFFSET;
}
- //free(buf);
- bb_error_msg_and_die("can't find file table");
+ free(buf);
+ return cde_header.formatted.cdf_offset;
};
static uint32_t read_next_cdf(uint32_t cdf_offset, cdf_header_t *cdf_ptr)
@@ -218,13 +228,15 @@ static uint32_t read_next_cdf(uint32_t cdf_offset, cdf_header_t *cdf_ptr)
if (!cdf_offset)
cdf_offset = find_cdf_offset();
- xlseek(zip_fd, cdf_offset + 4, SEEK_SET);
- xread(zip_fd, cdf_ptr->raw, CDF_HEADER_LEN);
- FIX_ENDIANNESS_CDF(*cdf_ptr);
- cdf_offset += 4 + CDF_HEADER_LEN
- + cdf_ptr->formatted.file_name_length
- + cdf_ptr->formatted.extra_field_length
- + cdf_ptr->formatted.file_comment_length;
+ if (cdf_offset != BAD_CDF_OFFSET) {
+ xlseek(zip_fd, cdf_offset + 4, SEEK_SET);
+ xread(zip_fd, cdf_ptr->raw, CDF_HEADER_LEN);
+ FIX_ENDIANNESS_CDF(*cdf_ptr);
+ cdf_offset += 4 + CDF_HEADER_LEN
+ + cdf_ptr->formatted.file_name_length
+ + cdf_ptr->formatted.extra_field_length
+ + cdf_ptr->formatted.file_comment_length;
+ }
xlseek(zip_fd, org, SEEK_SET);
return cdf_offset;
@@ -233,8 +245,9 @@ static uint32_t read_next_cdf(uint32_t cdf_offset, cdf_header_t *cdf_ptr)
static void unzip_skip(off_t skip)
{
- if (lseek(zip_fd, skip, SEEK_CUR) == (off_t)-1)
- bb_copyfd_exact_size(zip_fd, -1, skip);
+ if (skip != 0)
+ if (lseek(zip_fd, skip, SEEK_CUR) == (off_t)-1)
+ bb_copyfd_exact_size(zip_fd, -1, skip);
}
static void unzip_create_leading_dirs(const char *fn)
@@ -535,21 +548,31 @@ int unzip_main(int argc, char **argv)
bb_error_msg_and_die("zip flag 1 (encryption) is not supported");
}
- {
+ if (cdf_offset != BAD_CDF_OFFSET) {
cdf_header_t cdf_header;
cdf_offset = read_next_cdf(cdf_offset, &cdf_header);
+ /*
+ * Note: cdf_offset can become BAD_CDF_OFFSET after the above call.
+ */
if (zip_header.formatted.zip_flags & SWAP_LE16(0x0008)) {
/* 0x0008 - streaming. [u]cmpsize can be reliably gotten
- * only from Central Directory. See unzip_doc.txt */
+ * only from Central Directory. See unzip_doc.txt
+ */
zip_header.formatted.crc32 = cdf_header.formatted.crc32;
zip_header.formatted.cmpsize = cdf_header.formatted.cmpsize;
zip_header.formatted.ucmpsize = cdf_header.formatted.ucmpsize;
}
if ((cdf_header.formatted.version_made_by >> 8) == 3) {
- /* this archive is created on Unix */
+ /* This archive is created on Unix */
dir_mode = file_mode = (cdf_header.formatted.external_file_attributes >> 16);
}
}
+ if (cdf_offset == BAD_CDF_OFFSET
+ && (zip_header.formatted.zip_flags & SWAP_LE16(0x0008))
+ ) {
+ /* If it's a streaming zip, we _require_ CDF */
+ bb_error_msg_and_die("can't find file table");
+ }
#endif
/* Read filename */