Bug#801925: NULL pointer dereference: IP: [<f828a00c>] sr_runtime_suspend+0xc/0x20 [sr_mod]

[Alan Stern <stern@rowland.harvard.edu>]

On Sat, 31 Oct 2015, Paul Menzel wrote:

> > Well, that didn't help much.  Paul hit another oops, this time in
> > sd_mod but again apparently related to runtime PM.  My patch only
> > touched sr_mod.
> > 
> > This time he sent photos of the complete oops; see
> > <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=801925;filename=20151020_005.jpg;att=4;msg=15>
> > and
> > <https://bugs.debian.org/cgi-bin/bugreport.cgi?filename=20151020_006.jpg;bug=801925;att=3;msg=15>
> 
> after backing up my data, I tested a little bit more, and using Linux
> 3.19 the drive is detected and the system boots.
> 
> Does anything stand out what changed in this area between Linux 3.19 and
> 4.1?

I believe the problem shown in that photo was fixed by commit
49718f0fb8c9 ("SCSI: Fix NULL pointer dereference in runtime PM"),
which was merged in 4.2 and has been back-ported to various stable 
releases.

Alan Stern