ext4: check block device size on mount
Signed-off-by: Thiemo Nagel <thiemo.nagel@ph.tum.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9987bba..2958f4e 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2508,6 +2508,15 @@
if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
goto cantfind_ext4;
+ /* check blocks count against device size */
+ blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
+ if (blocks_count && ext4_blocks_count(es) > blocks_count) {
+ printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu "
+ "exceeds size of device (%llu blocks)\n",
+ ext4_blocks_count(es), blocks_count);
+ goto failed_mount;
+ }
+
/*
* It makes no sense for the first data block to be beyond the end
* of the filesystem.