Re: [PATCH] iio: multiplexer: add NULL check on devm_kzalloc() return value

[Gustavo A. R. Silva]

Quoting Peter Rosin <peda@xxxxxxxxxx>:

> On 2017-07-07 06:35, Gustavo A. R. Silva wrote:
> > Hi Peter,
> >
> > Quoting Peter Rosin <peda@xxxxxxxxxx>:
> >
> > > On 2017-07-07 00:08, Gustavo A. R. Silva wrote:
> > > > Check return value from call to devm_kzalloc()
> > > > in order to prevent a NULL pointer dereference.
> > >
> > > Right, thanks for finding that one! There's another one inside the
> > > for loop that is just starting in the context of this patch. Care
> > > to fix checking the return value of that devm_kmemdup as well?
> >
> > Sure, I'll send a new patch shortly.
> >
> > > And someone should perhaps teach Coccinelle about devm_kmemdup...
> >
> > Good catch, I just implemented that script.
> >
> > > > This issue was detected using Coccinelle and the following semantic patch:
> > > >
> > > > @@
> > > > expression x;
> > > > identifier fld;
> > > > @@
> > > >
> > > > * x = devm_kzalloc(...);
> > > >   ... when != x == NULL
> > > >   x->fld
> > >
> > > One of these blank lines should perhaps be a "Fixes:" tag?
> >
> > mmm, I don't get this...
>
> If you add a Fixes-tag, like below, you help the stable kernel maintainers
> decide what to look at. In this case it might be overkill since the thing
> you fix is so fresh and does not apply to any old kernel. But I think it
> is a good habit...
>
> Fixes: 7ba9df54b091 ("iio: multiplexer: new iio category and iio-mux driver")
>
> (and it is a bit unusual to see two blank lines before the SoB-tag)
>
> Sorry for not spelling it out the first time.

Oh, I get it now. Thank you very much for clarifying. I will  
definitely keep that in mind for future fixes when that could apply.

Thanks!
--
Gustavo A. R. Silva