Fix possible crash if bitmap metadata is bad.

We really should never divide by 0.

Thanks to "Jon Nelson" <jnelson-linux-raid@jamponi.net>
for finding the problem.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/bitmap.c b/bitmap.c
index b647939..352be5d 100644
--- a/bitmap.c
+++ b/bitmap.c
@@ -162,7 +162,7 @@ bitmap_info_t *bitmap_fd_read(int fd, int brief)
 
 	sb_le_to_cpu(&info->sb); /* convert superblock to CPU byte ordering */
 
-	if (brief || info->sb.sync_size == 0)
+	if (brief || info->sb.sync_size == 0 || info->sb.chunksize == 0)
 		goto out;
 
 	/* read the rest of the file counting total bits and dirty bits --