Re: [PATCH] tpm: Check the bios_dir entry for NULL before accessing it

[Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Wed, Nov 16, 2016 at 02:06:33PM -0800, Jarkko Sakkinen wrote:
> On Wed, Nov 16, 2016 at 01:38:53PM -0700, Jason Gunthorpe wrote:
> > On Wed, Nov 16, 2016 at 08:56:13AM -0500, Stefan Berger wrote:
> > > Check the bios_dir entry for NULL before accessing it. Currently
> > > this crashes the driver when a TPM 2 is attached and the entries
> > > are NULL.
> > 
> > Yep
> > 
> > >  	for (i = (TPM_NUM_EVENT_LOG_FILES - 1); i >= 0; i--) {
> > > -		inode = d_inode(chip->bios_dir[i]);
> > > -		inode_lock(inode);
> > > -		inode->i_private = NULL;
> > > -		inode_unlock(inode);
> > > -		securityfs_remove(chip->bios_dir[i]);
> > > +		if (chip->bios_dir[i]) {
> > 
> > Nope, this must be is_err_or_null, we store err ptrs in this array.
> 
> "
> err:
>         chip->bios_dir[cnt] = NULL;
> "
> 
> There is assignment to NULL so this should be fine.

Applied. Not yet squashed. I'll save that for the next week and possible
other squashes to the point when I prepare the pull request.

/Jarkko

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