btrfs: promote debugging asserts to full-fledged checks in validate_super

commit aefd7f7065567a4666f42c0fc8cdb379d2e036bf upstream.

Syzbot managed to trigger this assert while performing its fuzzing.
Turns out it's better to have those asserts turned into full-fledged
checks so that in case buggy btrfs images are mounted the users gets
an error and mounting is stopped. Alternatively with CONFIG_BTRFS_ASSERT
disabled such image would have been erroneously allowed to be mounted.

Reported-by: syzbot+a6bf271c02e4fe66b4e4@syzkaller.appspotmail.com
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add uuids to the messages ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nikolay Borisov 2021-05-31 12:26:01 +03:00 committed by Greg Kroah-Hartman
parent d4b047651f
commit 298499d73d
1 changed files with 18 additions and 8 deletions

View File

@ -2463,6 +2463,24 @@ static int validate_super(struct btrfs_fs_info *fs_info,
ret = -EINVAL;
}
if (memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid,
BTRFS_FSID_SIZE)) {
btrfs_err(fs_info,
"superblock fsid doesn't match fsid of fs_devices: %pU != %pU",
fs_info->super_copy->fsid, fs_info->fs_devices->fsid);
ret = -EINVAL;
}
if (btrfs_fs_incompat(fs_info, METADATA_UUID) &&
memcmp(fs_info->fs_devices->metadata_uuid,
fs_info->super_copy->metadata_uuid, BTRFS_FSID_SIZE)) {
btrfs_err(fs_info,
"superblock metadata_uuid doesn't match metadata uuid of fs_devices: %pU != %pU",
fs_info->super_copy->metadata_uuid,
fs_info->fs_devices->metadata_uuid);
ret = -EINVAL;
}
if (memcmp(fs_info->fs_devices->metadata_uuid, sb->dev_item.fsid,
BTRFS_FSID_SIZE) != 0) {
btrfs_err(fs_info,
@ -2837,14 +2855,6 @@ int open_ctree(struct super_block *sb,
disk_super = fs_info->super_copy;
ASSERT(!memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid,
BTRFS_FSID_SIZE));
if (btrfs_fs_incompat(fs_info, METADATA_UUID)) {
ASSERT(!memcmp(fs_info->fs_devices->metadata_uuid,
fs_info->super_copy->metadata_uuid,
BTRFS_FSID_SIZE));
}
features = btrfs_super_flags(disk_super);
if (features & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) {