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Commit e3540eab authored by David Sterba's avatar David Sterba Committed by Chris Mason
Browse files

btrfs: add more checks to btrfs_read_sys_array 



Verify that the sys_array has enough bytes to read the next item.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 1ffb22cf

fs/btrfs/volumes.c

+23 −3
Original line number Diff line number Diff line
@@ -6296,20 +6296,34 @@ int btrfs_read_sys_array(struct btrfs_root *root) 


	while (cur_offset < array_size) {

		disk_key = (struct btrfs_disk_key *)array_ptr;

		len = sizeof(*disk_key);

		if (cur_offset + len > array_size)

			goto out_short_read;



		btrfs_disk_key_to_cpu(&key, disk_key);



		len = sizeof(*disk_key);

		array_ptr += len;

		sb_array_offset += len;

		cur_offset += len;



		if (key.type == BTRFS_CHUNK_ITEM_KEY) {

			chunk = (struct btrfs_chunk *)sb_array_offset;

			/*

			 * At least one btrfs_chunk with one stripe must be

			 * present, exact stripe count check comes afterwards

			 */

			len = btrfs_chunk_item_size(1);

			if (cur_offset + len > array_size)

				goto out_short_read;



			num_stripes = btrfs_chunk_num_stripes(sb, chunk);

			len = btrfs_chunk_item_size(num_stripes);

			if (cur_offset + len > array_size)

				goto out_short_read;



			ret = read_one_chunk(root, &key, sb, chunk);

			if (ret)

				break;

			num_stripes = btrfs_chunk_num_stripes(sb, chunk);

			len = btrfs_chunk_item_size(num_stripes);

		} else {

			ret = -EIO;

			break;
@@ -6320,6 +6334,12 @@ int btrfs_read_sys_array(struct btrfs_root *root) 
	}

	free_extent_buffer(sb);

	return ret;



out_short_read:

	printk(KERN_ERR "BTRFS: sys_array too short to read %u bytes at offset %u\n",

			len, cur_offset);

	free_extent_buffer(sb);

	return -EIO;

}



int btrfs_read_chunk_tree(struct btrfs_root *root)