Re: [PATCH] selftests/resctrl: Fix null pointer dereference on open failed

[Shuah Khan]

On 4/25/22 10:06 AM, Colin King (gmail) wrote:
> On 25/04/2022 16:51, Shuah Khan wrote:
> > On 4/24/22 3:15 PM, Colin Ian King wrote:
> > > Currently if opening /dev/null fails to open then file pointer fp
> > > is null and further access to fp via fprintf will cause a null
> > > pointer dereference. Fix this by returning a negative error value
> > > when a null fp is detected.
> >
> > How did you find this problem and how can it be reproduced? Is there
> > a case where test fails to open "/dev/null"?
>
> Found with static analysis, cppcheck. Open on /dev/null is unlikely to fail, but it's good to fail reliably rather than have a SIGSEGV :-)

I don't see how /dev/null open could fail here in this test.
However, I will take this fix. Please add information how
you found it and include the cppheck log in the commit log
and send me v2.

thanks,
-- Shuah