Squashfs: add missing check in zlib_wrapper

On file system corruption zlib can return Z_STREAM_OK with
input buffers remaining, which will not be released.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

1 files changed, 5 insertions, 0 deletions

diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 1f4833b87ea3..ab5801f66e26 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -127,6 +127,11 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
                 goto release_mutex;
         }
 
+        if (k < b) {
+                ERROR("zlib_uncompress error, data remaining\n");
+                goto release_mutex;
+        }
+
         length = stream->total_out;
         mutex_unlock(&msblk->read_data_mutex);
         return length;