Re: ocfs2: xattr problems with 5.4.0-rc7

From: Joseph Qi
Date: Tue Nov 12 2019 - 20:28:49 EST


Hi Thomas,
Thanks for reporting this issue.
I have some doubts on it, please see my comments below.

On 19/11/12 22:45, Thomas Voegtle wrote:
>
> Hello,
>
> with 5.4.0-rc7 and 4.9.200 we see the following errors with mkdir or touch on a ocfs2 mountpoint:
>
> root@s2:/shared/ClusterShareDisk# mkdir dir
> mkdir: cannot create directory ʽdirʼ: Invalid argument
>
> which produces this output:
>
> root@s2:/shared/ClusterShareDisk# dmesg
> [ 6918.815770] (mkdir,19461,0):ocfs2_xa_set:2242 ERROR: status = -22
> [ 6918.815772] (mkdir,19461,0):ocfs2_mknod:408 ERROR: status = -22
> [ 6918.816215] (mkdir,19461,0):ocfs2_mknod:486 ERROR: status = -22
> [ 6918.816216] (mkdir,19461,0):ocfs2_mkdir:652 ERROR: status = -22
>
ocfs2_xa_set
ocfs2_xa_prepare_entry

Since ocfs2_xa_set() returns -EINVAL, it means loc->xl_entry is NULL.

if (!loc->xl_entry) {
rc = -EINVAL;
goto out;
}

After reverting
commit 56e94ea132bb "fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()",
it will call ocfs2_xa_add_entry(),

if (loc->xl_entry) {
...
} else
ocfs2_xa_add_entry(loc, name_hash);

Theoretically it will cause NULL pointer dereference when access attributes of loc->xl_entry.
So could you please check if the issue is caused by NULL loc->xl_entry?

Thanks,
Joseph

> We got some ACLs:
> $ getfacl /shared/ClusterShareDisk/
> getfacl: Removing leading '/' from absolute path names
> # file: shared/ClusterShareDisk/
> # owner: root
> # group: root
> user::rwx
> user:admin:rwx
> group::rwx
> mask::rwx
> other::---
> default:user::rwx
> default:user:admin:rwx
> default:group::rwx
> default:mask::rwx
> default:other::---
>
> And of course it is mounted with user_xattr and acl option.
>
> Reverting
> commit 56e94ea132bb5c2c1d0b60a6aeb34dcb7d71a53d
> Author: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
> Date:   Sun Oct 6 17:57:50 2019 -0700
>
>     fs: ocfs2: fix possible null-pointer dereferences in
> ocfs2_xa_prepare_entry()
>
> fixes the problem.
>
> Greetings,
>
>
>     Thomas