Re: [PATCH v2 1/4] usb: typec: ucsi: Fix null deref in trace

Re: [PATCH v2 1/4] usb: typec: ucsi: Fix null deref in trace

[Markus Elfring]

…
> ucsi_register_altmode checks IS_ERR on returned pointer and treats
> NULL as valid. This results in a null deref when
> trace_ucsi_register_altmode is called.
…

Can it be nicer to use the term “null pointer dereference” for
the commit message here?

Regards,
Markus

Re: [PATCH v2 1/4] usb: typec: ucsi: Fix null deref in trace

[Greg Kroah-Hartman]

On Thu, Apr 25, 2024 at 10:51:53AM +0200, Markus Elfring wrote:
> …
> > ucsi_register_altmode checks IS_ERR on returned pointer and treats
> > NULL as valid. This results in a null deref when
> > trace_ucsi_register_altmode is called.
> …
> 
> Can it be nicer to use the term “null pointer dereference” for
> the commit message here?
> 
> Regards,
> Markus

Hi,

This is the semi-friendly patch-bot of Greg Kroah-Hartman.

Markus, you seem to have sent a nonsensical or otherwise pointless
review comment to a patch submission on a Linux kernel developer mailing
list.  I strongly suggest that you not do this anymore.  Please do not
bother developers who are actively working to produce patches and
features with comments that, in the end, are a waste of time.

Patch submitter, please ignore Markus's suggestion; you do not need to
follow it at all.  The person/bot/AI that sent it is being ignored by
almost all Linux kernel maintainers for having a persistent pattern of
behavior of producing distracting and pointless commentary, and
inability to adapt to feedback.  Please feel free to also ignore emails
from them.

thanks,

greg k-h's patch email bot

Re: [PATCH v2 1/4] usb: typec: ucsi: Fix null deref in trace

[Jameson Thies]

Hi Dmitry,
what are your thoughts on Abhishek's comment? I think we should
attempt to register the alternate mode when CONFIG_TYPEC_DP_ALTMODE is
not enabled. It would give us a more accurate representation of the
partner in user space. I understand your point about ignoring a
potential EOPNOTSUPP response from the non-stub function. What if we
leave ucsi.c alone, and replace the stub function's null return with a
call to typec_port_register_altmode(). That would register DP altmode
as an unsupported mode when CONFIG_TYPEC_DP_ALTMODE is not enabled,
and fix the null pointer dereference. But, it won't change behavior
when CONFIG_TYPEC_DP_ALTMODE is enabled.

Hi Markus,
thanks for your feedback. I'll update the commit message to say "null
pointer dereference" when I upload a v3 series.

Thanks,
Jameson

Re: [PATCH v2 1/4] usb: typec: ucsi: Fix null deref in trace

[Dmitry Baryshkov]

On Mon, Apr 29, 2024 at 05:43:16PM -0700, Jameson Thies wrote:
> Hi Dmitry,
> what are your thoughts on Abhishek's comment? I think we should
> attempt to register the alternate mode when CONFIG_TYPEC_DP_ALTMODE is
> not enabled. It would give us a more accurate representation of the
> partner in user space. I understand your point about ignoring a
> potential EOPNOTSUPP response from the non-stub function. What if we
> leave ucsi.c alone, and replace the stub function's null return with a
> call to typec_port_register_altmode(). That would register DP altmode
> as an unsupported mode when CONFIG_TYPEC_DP_ALTMODE is not enabled,
> and fix the null pointer dereference. But, it won't change behavior
> when CONFIG_TYPEC_DP_ALTMODE is enabled.

Yes, this sounds like a perfect idea!

> 
> Hi Markus,
> thanks for your feedback. I'll update the commit message to say "null
> pointer dereference" when I upload a v3 series.
> 
> Thanks,
> Jameson

-- 
With best wishes
Dmitry

Re: [PATCH v2 1/4] usb: typec: ucsi: Fix null deref in trace

[Jameson Thies]

Great! I'll post a v3 series applying this shortly.

Thanks,
Jameson