When filling the bit buffer, gzip decompression apparently never checked for end of file, causing it to hang on corrupted input.

1 files changed, 4 insertions, 1 deletions

diff --git a/archival/libunarchive/decompress_unzip.c b/archival/libunarchive/decompress_unzip.c
index e8cf54bff..b17065d92 100644
--- a/archival/libunarchive/decompress_unzip.c
+++ b/archival/libunarchive/decompress_unzip.c
@@ -151,7 +151,10 @@ static unsigned int fill_bitbuffer(unsigned int bitbuffer, unsigned int *current
                         /* Leave the first 4 bytes empty so we can always unwind the bitbuffer
                          * to the front of the bytebuffer, leave 4 bytes free at end of tail
                          * so we can easily top up buffer in check_trailer_gzip() */
-                        bytebuffer_size = 4 + bb_xread(gunzip_src_fd, &bytebuffer[4], bytebuffer_max - 8);
+                        if (!(bytebuffer_size = bb_xread(gunzip_src_fd, &bytebuffer[4], bytebuffer_max - 8))) {
+                                bb_error_msg_and_die("unexpected end of file");
+                        }
+                        bytebuffer_size += 4;
                         bytebuffer_offset = 4;
                 }
                 bitbuffer |= ((unsigned int) bytebuffer[bytebuffer_offset]) << *current;