From 99e3ecfcb9f4ca35192d20a5bea158b81f600062 Mon Sep 17 00:00:00 2001
From: Liu Bo <bo.li.liu@oracle.com>
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 <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>
---
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);
--
2.49.0