omfs: refuse to mount if bitmap pointer is obviously wrong
If the free space bitmap pointer is corrupted such that it lies outside
of the number of blocks in the filesystem, print a message and fail the
mount so the user can fix it offline.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
diff --git a/fs/omfs/inode.c b/fs/omfs/inode.c
index bd4bf75..0af5d0a 100644
--- a/fs/omfs/inode.c
+++ b/fs/omfs/inode.c
@@ -509,6 +509,15 @@
goto out_brelse_bh2;
}
+ if (sbi->s_bitmap_ino != ~0ULL &&
+ sbi->s_bitmap_ino > sbi->s_num_blocks) {
+ printk(KERN_ERR "omfs: free space bitmap location is corrupt "
+ "(%llx, total blocks %llx)\n",
+ (unsigned long long) sbi->s_bitmap_ino,
+ (unsigned long long) sbi->s_num_blocks);
+ goto out_brelse_bh2;
+ }
+
ret = omfs_get_imap(sb);
if (ret)
goto out_brelse_bh2;