cifs doesn't support connecting as guest

[jablko]

Binary package hint: samba

I'm using a stock Edgy installation. I simply enabled Samba using the GUI tools and tried connecting from another Linux machine. The mount.cifs manpage describes a "guest" option, but connecting with this option doesn't work:

ket% sudo mount.cifs //mog.local/share /mnt -o guest
mount error 13 = Permission denied
Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)
ket%

However this option does work with mount.smb vs. mount.cifs:

ket% sudo mount.smb //mog.local/share /mnt -o guest
Anonymous login successful
ket%

As a workaround, I created a user "anonymous" with blank password:

ket% sudo mount.cifs //mog.local/share /mnt -o user=anonymous,password=
ket% ls /mnt
Movies MythVideo
ket%

However this is not a perfect solution: The autofs package's /etc/auto.smb script uses cifs by default and I don't want to have to create a credfile for "anonymous" with blank password, I want autofs to work with my Ubuntu Samba server out of the box.

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=416515

Why doesn't connecting to Ubuntu with cifs and the guest option work like connecting to Ubuntu with smb and the guest option?

What needs to change so:

ket% sudo mount.cifs //mog.local/share /mnt

- or -

ket% sudo mount.cifs //mog.local/share /mnt -o guest

successfully connect, thereby enabling autofs to work out of the box?

Thanks for maintaining Samba in Ubuntu! Jack

[Chuck Short (zulcss)]

Hello,

Does the work around mention in the debian bug report work for you?

Thanks
chuck

[jablko (ms419)]

Thanks Chuck, I followed up on the Debian bug with automount. sec=none does enable mount.cifs to connect without username or password, but now results in automount kernel panics. Incidentally I experience the same kernel panics with Ubuntu automount. Will continue to work on the automount issues, unless you have input on how to proceed?

Thanks and best wishes, Jack

[Chuck Short (zulcss)]

Hi,

If possible can you test this with the hardy live cd. Also it would be nice if you can attach your kernel oops that you get.

Thanks
chuck

[jablko (ms419)]

Thanks Chuck, I had a chance this evening to test with the Hardy alpha 4 live CD and indeed, I no longer see the kernel oops. The kernel oops I used to get is below.

So the workaround mentioned in the Debian bug report now works. Changing my /etc/auto.smb as follows enables me to connect to my Ubuntu Samba server with autofs:

--- /etc/auto.smb 2007/03/29 15:27:45 1.1
+++ /etc/auto.smb 2008/01/18 16:08:28
@@ -24,6 +24,7 @@
        mountopts="$mountopts,credentials=$credfile"
        smbopts="-A $credfile"
 else
+ mountopts="$mountopts,sec=none"
        smbopts="-N"
 fi

So "mount.smb -o guest" works:

ket% sudo mount.smb //mog.local/share /mnt -o guest
Anonymous login successful
ket%

- but "mount.cifs -o guest" does not work:

ket% sudo mount.cifs //mog.local/share /mnt -o guest
mount error 13 = Permission denied
Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)
ket%

- but "mount.cifs -o sec=none" does work:

ket% sudo mount.cifs //mog.local/share /mnt -o sec=none
ket% ls /mnt
Movies MythVideo
ket%

So, *should* "mount.cifs -o guest" work like "mount.smb -o guest", or should /etc/auto.smb use "sec=none"?

Much thanks for all your help with this issue Chuck, Jack

Jan 18 09:44:16 ket kernel: CIFS VFS: Send error in SessSetup = -13
Jan 18 09:44:16 ket kernel: CIFS VFS: cifs_mount failed w/return code =
-13
Jan 18 09:44:27 ket kernel: CIFS VFS: Send error in SessSetup = -13
Jan 18 09:44:27 ket kernel: CIFS VFS: cifs_mount failed w/return code =
-13
Jan 18 09:46:23 ket kernel: BUG: unable to handle kernel NULL pointer
dereference at virtual address 00000000
Jan 18 09:46:23 ket automount[4818]: mount(generic): failed to
mount //mog.local/print (type cifs) on /smb/mog.local/print
Jan 18 09:46:23 ket kernel: printing eip:
Jan 18 09:46:23 ket kernel: f8f48183
Jan 18 09:46:23 ket kernel: *pde = 00000000
Jan 18 09:46:23 ket kernel: Oops: 0000 [#1]
Jan 18 09:46:23 ket kernel: SMP
Jan 18 09:46:23 ket kernel: Modules linked in: nls_iso8859_1 cifs i915
drm rfcomm l2cap bluetooth ppdev parport_pc lp parport button ac battery
autofs4 ipv6 acpi_cpufreq cpufreq_conservative cpufreq_powersave
cpufreq_stats cpufreq_userspace cpufreq_ondemand freq_table fuse
firewire_sbp2 loop joydev tsdev snd_hda_intel pcmcia snd_pcm_oss
snd_mixer_oss snd_pcm sdhci ipw3945 snd_timer mmc_core ieee80211
ieee80211_crypt yenta_socket rsrc_nonstatic pcmcia_core rtc snd iTCO_wdt
firmware_class i2c_i801 i2c_core soundcore snd_page_alloc psmouse
serio_raw intel_agp agpgart evdev ext3 jbd mbcache dm_mirror dm_snapshot
dm_mod sg sr_mod sd_mod cdrom 8139cp ata_piix ata_generic libata
scsi_mod firewire_ohci firewire_core crc_itu_t 8139too mii ehci_hcd
generic ide_core uhci_hcd usbcore thermal processor fan
Jan 18 09:46:23 ket kernel: CPU: 0
Jan 18 09:46:23 ket kernel: EIP: 0060:[<f8f48183>] Not tainted VLI
Jan 18 09:46:23 ket kernel: EFLAGS: 00010212 (2.6.22-3-686 #1)
Jan 18 09:46:23 ket kernel: EIP is at cifs_find_tcp_session+0x77/0xc0
[cifs]
Jan 18 09:46:23 ket kernel: eax: c747dd00 ebx: 00000000 ecx:
0000001f edx: c747dd7c
Jan 18 09:46:23 ket kernel: esi: f688c569 edi: 00000000 ebp:
f688c500 esp: c747dca4
Jan 18 ...

[Forest (foresto)]

Does "fix released" mean that something was changed in an upcoming samba release such that sec=none is no longer required for guest connections? Or, will we have to use sec=none forever?

[Thierry Carrez (ttx)]

It means this bug (not able to connect as guest using CIFS) was fixed. Reading man mount.cifs shows that you should use sec=none on connections with the NULL user ("guest" connections), so that's not a bug that will be fixed.