[Thinlinc-technical] Kernel panic with Ubuntu 12.10 and mounting/unmounting USB drives with thinlinc

Wed Jul 10 15:52:36 CEST 2013

Is it the kernel on the client or the server that crashes? Is it a 32- or 
64-bit system?

Regards,
Peter

>
>
>Hello,
>
>recently we are excessively testing the mounting and unmounting of USB 
>devices through ThinLinc and have came across a problem that seems to 
>prevent us from using the functionality to mount local drives with 
>thinlinc. In fact, what our users are doing are that they insert a USB 
>thumb drive into our Thinclient (NUC). Then they use the 
>tl-mount-localdrives command. Afterwards they "cd" into the corresponding 
>directory, do something and unmount it afterwards using 
>tl-umount-localdrives. This procedure is repeated several times. 
>Unfortunately there seems to be a problem at least with the kernels 
>supplied with ubuntu 12.10 as they seem to crash badly as you can see by 
>the attached crash log.
>
>I am now of course curious if this problem is known, if there exists a 
>workaround or did anyone run into the same problems yet? As said, this 
>behavior currently prevents us from using the local drives mount 
>functionality of thinlinc which we would really love to have.
>
>best regards,
>jens
>
>-- cut here --
>Jul  4 09:52:35 saturn kernel: [156591.684621] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
>Jul  4 09:52:35 saturn kernel: [156591.684659] IP: [<ffffffff811a0062>] commit_tree+0x82/0x100
>Jul  4 09:52:35 saturn kernel: [156591.684686] PGD 78da91067 PUD 78da90067 PMD 0 
>Jul  4 09:52:35 saturn kernel: [156591.684720] Oops: 0000 [#1] SMP 
>Jul  4 09:52:35 saturn kernel: [156591.684744] CPU 50 
>Jul  4 09:52:35 saturn kernel: [156591.684751] Modules linked in: ipmi_devintf ipmi_si ipmi_msghandler autofs4 parport_pc ppdev binfmt_misc kvm_amd kvm ghash
>_clmulni_intel aesni_intel cryptd aes_x86_64 sp5100_tco microcode psmouse serio_raw joydev amd64_edac_mod fam15h_power k10temp edac_core edac_mce_amd i2c_pii
>x4 bnep rfcomm bluetooth mac_hid w83795 w83627ehf hwmon_vid nfsd lp parport nfs lockd fscache auth_rpcgss nfs_acl sunrpc hid_generic usbhid hid pata_atiixp a
>hci qla2xxx igb libahci dca scsi_transport_fc megaraid_sas scsi_tgt usb_storage
>Jul  4 09:52:35 saturn kernel: [156591.685081] 
>Jul  4 09:52:35 saturn kernel: [156591.685089] Pid: 10693, comm: bash Not tainted 3.5.0-34-generic #55-Ubuntu Supermicro H8QG6/H8QG6
>Jul  4 09:52:35 saturn kernel: [156591.685133] RIP: 0010:[<ffffffff811a0062>]  [<ffffffff811a0062>] commit_tree+0x82/0x100
>Jul  4 09:52:35 saturn kernel: [156591.685159] RSP: 0018:ffff881a57971bb8  EFLAGS: 00010212
>Jul  4 09:52:35 saturn kernel: [156591.685176] RAX: ffff881a57971b38 RBX: ffff881a57971bf8 RCX: ffff881a57971bb8
>Jul  4 09:52:35 saturn kernel: [156591.685265] RDX: ffff881bc5c2dd80 RSI: ffff881bc5c2dd00 RDI: 0000000000000000
>Jul  4 09:52:35 saturn kernel: [156591.685345] RBP: ffff881a57971bc8 R08: ffff882006d09e00 R09: 0000000000000100
>Jul  4 09:52:35 saturn kernel: [156591.685426] R10: ffffea00203fe780 R11: ffffffffa01c9b00 R12: ffff881bc5c2dd00
>Jul  4 09:52:35 saturn kernel: [156591.685521] R13: 0000000000000000 R14: ffff881a57971dd8 R15: ffff882006d09e20
>Jul  4 09:52:35 saturn kernel: [156591.685603] FS:  00007faefd820700(0000) GS:ffff881c17c80000(0000) knlGS:00000000e72ffb40
>Jul  4 09:52:35 saturn kernel: [156591.685688] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>Jul  4 09:52:35 saturn kernel: [156591.685738] CR2: 0000000000000018 CR3: 000000078d908000 CR4: 00000000000407e0
>Jul  4 09:52:35 saturn kernel: [156591.685821] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>Jul  4 09:52:35 saturn kernel: [156591.685906] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
>Jul  4 09:52:35 saturn kernel: [156591.685987] Process bash (pid: 10693, threadinfo ffff881a57970000, task ffff881b6565c500)
>Jul  4 09:52:35 saturn kernel: [156591.686071] Stack:
>Jul  4 09:52:35 saturn kernel: [156591.686108]  ffff881bc5c2dd80 ffff881bc5c2dd80 ffff881a57971c38 ffffffff811a1838
>Jul  4 09:52:35 saturn kernel: [156591.686227]  ffff881a57971be8 0000000000000000 ffff882006d09e00 ffff88040ff12b40
>Jul  4 09:52:35 saturn kernel: [156591.686331]  ffff881a57971bf8 ffff881a57971bf8 ffff881a57971c48 ffff881a57971dd8
>Jul  4 09:52:35 saturn kernel: [156591.686433] Call Trace:
>Jul  4 09:52:35 saturn kernel: [156591.686482]  [<ffffffff811a1838>] attach_recursive_mnt+0x1b8/0x1c0
>Jul  4 09:52:35 saturn kernel: [156591.686542]  [<ffffffff811a1895>] graft_tree+0x55/0x90
>Jul  4 09:52:35 saturn kernel: [156591.686598]  [<ffffffff811a198f>] do_add_mount+0xbf/0xe0
>Jul  4 09:52:35 saturn kernel: [156591.686654]  [<ffffffff811a0e8d>] ? mnt_get_count+0x4d/0x70
>Jul  4 09:52:35 saturn kernel: [156591.686726]  [<ffffffff811a2507>] finish_automount+0x57/0xf0
>Jul  4 09:52:35 saturn kernel: [156591.686784]  [<ffffffff8118dbee>] follow_managed+0x1ae/0x2d0
>Jul  4 09:52:35 saturn kernel: [156591.686841]  [<ffffffff8118f661>] lookup_fast+0x1c1/0x310
>Jul  4 09:52:35 saturn kernel: [156591.686899]  [<ffffffff8119132c>] path_lookupat+0x11c/0x720
>Jul  4 09:52:35 saturn kernel: [156591.686956]  [<ffffffff8118d653>] ? putname+0x33/0x50
>Jul  4 09:52:35 saturn kernel: [156591.687011]  [<ffffffff811924d8>] ? user_path_at_empty+0x68/0xa0
>Jul  4 09:52:35 saturn kernel: [156591.687073]  [<ffffffff8116e681>] ? kmem_cache_alloc+0x31/0x130
>Jul  4 09:52:35 saturn kernel: [156591.687131]  [<ffffffff81191961>] do_path_lookup+0x31/0xc0
>Jul  4 09:52:35 saturn kernel: [156591.687187]  [<ffffffff8118d563>] ? getname_flags+0x53/0xf0
>Jul  4 09:52:35 saturn kernel: [156591.687244]  [<ffffffff811924cd>] user_path_at_empty+0x5d/0xa0
>Jul  4 09:52:35 saturn kernel: [156591.687304]  [<ffffffff811875bb>] ? vfs_stat+0x1b/0x20
>Jul  4 09:52:35 saturn kernel: [156591.687360]  [<ffffffff811877ea>] ? sys_newstat+0x1a/0x40
>Jul  4 09:52:35 saturn kernel: [156591.687416]  [<ffffffff81192521>] user_path_at+0x11/0x20
>Jul  4 09:52:35 saturn kernel: [156591.687473]  [<ffffffff81181853>] sys_chdir+0x23/0x90
>Jul  4 09:52:35 saturn kernel: [156591.687532]  [<ffffffff8168a429>] system_call_fastpath+0x16/0x1b
>Jul  4 09:52:35 saturn kernel: [156591.687584] Code: 48 8d 42 80 74 22 0f 1f 00 48 89 b8 d8 00 00 00 f0 ff 40 40 48 8b 90 80 00 00 00 48 39 ca 48 8d 42 80 75
> e5 48 8b 55 f0 48 39 ca <48> 8b 47 18 74 15 48 8b 08 4c 8b 4d f8 48 89 42 08 48 89 10 49 
>Jul  4 09:52:35 saturn kernel: [156591.687977] RIP  [<ffffffff811a0062>] commit_tree+0x82/0x100
>Jul  4 09:52:35 saturn kernel: [156591.688030]  RSP <ffff881a57971bb8>
>Jul  4 09:52:35 saturn kernel: [156591.688072] CR2: 0000000000000018
>Jul  4 09:52:35 saturn kernel: [156591.688564] ---[ end trace cc8c3aa8321f8b62 ]---
>-- cut here --
>
>

---
Peter Astrand		ThinLinc Chief Developer
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