Re: SCSI Oops: Unable to handle kernel NULL ptr dereference

[Cedric Sodhi <cedric.sodhi@rwth-aachen.de>]

I apologize if this message should reach you twice, I'm having trouble with the original mail account.

Since the problem is fixed it didn't seem necessary to me to say that, but I later recalled what was different that could have caused the problem. I used a SATA to USB controller and while the disk was mounted and read from, I noticed that the SATA wasn't correctly plugged in (although it worked). When I attempted to adjust the plug proplery, the link broke (i.e. on the SATA side, not the USB side). I re-mounted afterwards and no persistent issue seemed to have been caused, but it might be the cause for this panic when I terminated wayland later (no idea what it has to do with wayland, but that's my only hypothesis).

Below is the part of dmesg:

usb 1-3: new high-speed USB device number 5 using xhci_hcd
usb 1-3: New USB device found, idVendor=174c, idProduct=55aa
usb 1-3: New USB device strings: Mfr=2, Product=3, SerialNumber=1
usb 1-3: Product: ASM1153 USB3.0 TO SATA
usb 1-3: Manufacturer: Liangteng
usb 1-3: SerialNumber: 1153201404001
usb-storage 1-3:1.0: USB Mass Storage device detected
usb-storage 1-3:1.0: Quirks match for vid 174c pid 55aa: 400000
scsi host3: usb-storage 1-3:1.0
scsi 3:0:0:0: Direct-Access     ASMT     2115             0    PQ: 0 ANSI: 6
sd 3:0:0:0: Attached scsi generic sg1 type 0
sd 3:0:0:0: [sdb] Spinning up disk...
ready
sd 3:0:0:0: [sdb] 625142448 512-byte logical blocks: (320 GB/298 GiB)
sd 3:0:0:0: [sdb] Write Protect is off
sd 3:0:0:0: [sdb] Mode Sense: 43 00 00 00
sd 3:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
 sdb: sdb1
sd 3:0:0:0: [sdb] Attached SCSI disk


On Thu, Aug 10, 2017 at 06:01:39PM -0400, Ewan D. Milne wrote:
> [cc's snipped to linux-scsi ]
> 
> On Thu, 2017-08-10 at 17:05 +0000, manday@openmail.cc wrote:
> > Hello,
> > 
> > I'd like to report this rare panic I experienced today. I've been on  
> > 4.12.3 since it was released and got this panic totally unexpected,  
> > probably when terminating my WL compositor. I attach to this message a  
> > capture of the screen. The problem occurred never before and never  
> > after since, suggesting I will not be able to reproduce it easily.  
> > Perhaps it means something to someone.
> > 
> > Linux air 4.12.3 #4 SMP Fri Jul 28 12:07:06 CEST 2017 x86_64 Intel(R)  
> > Core(TM)i5-6267U CPU @ 2.90GHz GenuineIntel GNU/Linux
> > 
> > I don't know what additional information might be useful so if there  
> > is anything else I should provide please tell me.
> > 
> > Best regards,
> > Cedric
> 
> Your stack trace indicates some kind of corruption in a kmem cache
> used by the SCSI code, uncovered when the block queue was being freed.
> Can you describe what SCSI hardware is connected to your machine?
> A snippet of your boot messages showing the hardware probe would help.
> 
> -Ewan
> 
>