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Commit 99e3ecfc authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

Btrfs: add more validation checks for superblock 



This adds validation checks for super_total_bytes, super_bytes_used and
super_stripesize, super_num_devices.

Reported-by: default avatarVegard Nossum <vegard.nossum@oracle.com>
Reported-by: default avatarQuentin Casasnovas <quentin.casasnovas@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent d865177a

fs/btrfs/disk-io.c

+11 −0
Original line number Diff line number Diff line
@@ -4130,6 +4130,17 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info, 
	 * Hint to catch really bogus numbers, bitflips or so, more exact checks are

	 * done later

	 */

	if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) {

		btrfs_err(fs_info, "bytes_used is too small %llu",

		       btrfs_super_bytes_used(sb));

		ret = -EINVAL;

	}

	if (!is_power_of_2(btrfs_super_stripesize(sb)) ||

	    btrfs_super_stripesize(sb) != sectorsize) {

		btrfs_err(fs_info, "invalid stripesize %u",

		       btrfs_super_stripesize(sb));

		ret = -EINVAL;

	}

	if (btrfs_super_num_devices(sb) > (1UL << 31))

		printk(KERN_WARNING "BTRFS: suspicious number of devices: %llu\n",

				btrfs_super_num_devices(sb));

fs/btrfs/volumes.c

+24 −0
Original line number Diff line number Diff line
@@ -6651,6 +6651,7 @@ int btrfs_read_chunk_tree(struct btrfs_root *root) 
	struct btrfs_key found_key;

	int ret;

	int slot;

	u64 total_dev = 0;



	root = root->fs_info->chunk_root;
@@ -6692,6 +6693,7 @@ int btrfs_read_chunk_tree(struct btrfs_root *root) 
			ret = read_one_dev(root, leaf, dev_item);

			if (ret)

				goto error;

			total_dev++;

		} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {

			struct btrfs_chunk *chunk;

			chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
@@ -6701,6 +6703,28 @@ int btrfs_read_chunk_tree(struct btrfs_root *root) 
		}

		path->slots[0]++;

	}



	/*

	 * After loading chunk tree, we've got all device information,

	 * do another round of validation checks.

	 */

	if (total_dev != root->fs_info->fs_devices->total_devices) {

		btrfs_err(root->fs_info,

	   "super_num_devices %llu mismatch with num_devices %llu found here",

			  btrfs_super_num_devices(root->fs_info->super_copy),

			  total_dev);

		ret = -EINVAL;

		goto error;

	}

	if (btrfs_super_total_bytes(root->fs_info->super_copy) <

	    root->fs_info->fs_devices->total_rw_bytes) {

		btrfs_err(root->fs_info,

	"super_total_bytes %llu mismatch with fs_devices total_rw_bytes %llu",

			  btrfs_super_total_bytes(root->fs_info->super_copy),

			  root->fs_info->fs_devices->total_rw_bytes);

		ret = -EINVAL;

		goto error;

	}

	ret = 0;

error:

	unlock_chunks(root);