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 <vegard.nossum@oracle.com>
Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 6628fca..2bd5f5e 100644 (file)
--- 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 42ccde4..fd5c9e6 100644 (file)
--- 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);