From: Nikolay Borisov nborisov@suse.com
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 --- fs/btrfs/disk-io.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-)
--- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2467,6 +2467,24 @@ static int validate_super(struct btrfs_f 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, @@ -2969,14 +2987,6 @@ int __cold open_ctree(struct super_block
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) {