Re: [PATCH] jsm_tty: Fix a possible null pointer dereference in two functions

[Joe Perches]

On Wed, 2017-11-29 at 17:35 +0000, Greg Kroah-Hartman wrote:
> On Wed, Nov 29, 2017 at 09:23:07AM -0800, Joe Perches wrote:
> > On Wed, 2017-11-29 at 17:40 +0100, SF Markus Elfring wrote:
> > > From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> > > Date: Wed, 29 Nov 2017 17:30:36 +0100
> > > 
> > > Move two debug messages so that a null pointer access can not happen
> > > for the variable "ch" in these functions.
> > 
> > An actual defect fix!
> 
> Nope, not at all, this does not "fix" anything.

Well, I believe it does in unusual cases like a
CONFIG_DYNAMIC_DEBUG when this is enabled by an
odd +p in the dynamic debug control file.

> > Here you could probably cc stable too.
> 
> Nope, not worth it.

<shrug>

It's pretty unlikely, but it is an actual defect.