Re: [PATCH 3/3] smb: client: show directory lease state in /proc/fs/cifs/open_dirs

[Paulo Alcantara <pc@manguebit.org>]

Enzo Matsumiya <ematsumiya@suse.de> writes:

> On 10/30, Paulo Alcantara wrote:
>>Bharath SM <bharathsm.hsk@gmail.com> writes:
>>
>>> Expose the SMB directory lease bits in the cached-dir proc
>>> output for debugging purposes.
>>>
>>> Signed-off-by: Bharath SM <bharathsm@microsoft.com>
>>> ---
>>>  fs/smb/client/cached_dir.c |  7 +++++++
>>>  fs/smb/client/cached_dir.h |  1 +
>>>  fs/smb/client/cifs_debug.c | 23 +++++++++++++++++++----
>>>  3 files changed, 27 insertions(+), 4 deletions(-)
>>
>>Are you increasing cached_fid structure just for debugging purposes?
>>That makes no sense.
>>
>>cached_fid structure has a dentry pointer, so what about accessing lease
>>flags as below
>>
>>        u8 lease_state = CIFS_I(d_inode(cfid->dentry))->oplock;
>
> Also, I don't think we can even get anything different than RH caching
> for dirs.

Yes.

> Even on RH -> R lease breaks (IIRC this can happen), we don't handle it
> and cfid is gone anyway.

Yep, that can happen.  The code also doesn't seem to handle any sort of
reference count on the @cfid being dumped out, which would definitely
cause UAF.