From 99e3ecfcb9f4ca35192d20a5bea158b81f600062 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Fri, 3 Jun 2016 12:05:14 -0700 Subject: [PATCH] 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: Vegard Nossum Reported-by: Quentin Casasnovas Reviewed-by: David Sterba Signed-off-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 11 +++++++++++ fs/btrfs/volumes.c | 24 ++++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 6628fca9f4ed..2bd5f5e975cc 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -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)); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 42ccde43053b..fd5c9e69894a 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -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); -- 2.20.1