Fwd: [Bug 201869] New: CIFS: block on llistxattr for SMB1

[Jeremy Allison]

On Tue, Dec 04, 2018 at 04:42:20PM -0600, Steve French wrote:
> On Tue, Dec 4, 2018 at 2:41 PM Jeremy Allison <jra at samba.org> wrote:
> >
> > On Tue, Dec 04, 2018 at 02:23:16PM -0600, Steve French wrote:
> > > This is a Samba server bug - see frame 17 of the trace I attached.
> > > The Samba server hung on the level 512 query info (and then hangs
> > > again after the client gives up and reconnects etc.).
> >
> > Yes, smbd doesn't support EA's on symlinks. That's probably not
> > going to change in the short term.
> 
> I am not worried about supporting EAs on symlinks here, I am worried
> about the fact
> that the Samba server was hanging (even on reboot Samba wouldn't stop).  I doubt
> that setfattr was relevant, but the fact that a getfattr hangs is a bad thing.
> 
> Basically not supporting EAs on symlinks is not the problem - hanging
> on querying symlinks is.
> 
> Repro is easy:
> 
> Just do "getfattr --absolute-names -dh -m user /mnt2/cifs/src-dir" on a symlink.
> 
> I tried it with Ubuntu 4.15 kernel and it hung Samba (server) the same way.
> The exact repro steps (in my example /test was exported as
> //localhost/test by Samba) were. The only non-default thing needed in
> mount is "vers=1.0"
> 
> root at smf-Thinkpad-P51:~# mount -t cifs //localhost/test /mnt2
> -ousername=testuser,vers=1.0
> root at smf-Thinkpad-P51:~# mkdir -m 0777 /test/cifs
> root at smf-Thinkpad-P51:~# mkdir /mnt2/cifs/target-dir
> root at smf-Thinkpad-P51:~# ln -s /mnt2/cifs/target-dir /mnt2/cifs/src-dir
> root at smf-Thinkpad-P51:~# setfattr -h -n user.name /mnt2/cifs/src-dir
> setfattr: /mnt2/cifs/src-dir: Operation not permitted
> root at smf-Thinkpad-P51:~# getfattr --absolute-names -dh -m user
> /mnt2/cifs/src-dir
> <hangs on server in smb1 querypathinfo processing>

Oh, I missed that. Can you get a debug level 10 log from the smbd ?