From: NeilBrown <neilb@suse.de>
Date: Mon, 2 Feb 2009 00:06:38 +0000 (+1100)
Subject: Fix possible crash if bitmap metadata is bad.
X-Git-Tag: mdadm-2.6.9~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b47dff6675026053dc574f305df570d79754484e;p=thirdparty%2Fmdadm.git

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>
---

diff --git a/bitmap.c b/bitmap.c
index b6479392..352be5d7 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 --