Re: [PATCH] tpm: Fix memory leak in tpmm_chip_alloc

[Jarkko Sakkinen]

On Tue, Mar 15, 2022 at 09:55:07AM +0800, Guozihua (Scott) wrote:
> 
> 
> On 2022/3/15 0:37, Jason Gunthorpe wrote:
> > On Mon, Mar 07, 2022 at 06:48:27PM +0800, GUO Zihua wrote:
> > > Fix a memory leak in tpmm_chip_alloc. devm_add_action_or_reset would
> > > call put_device on error, while tpm->devs is left untouched. Call
> > > put_device on tpm->devs as well if devm_add_action_or_reset returns an
> > > error.
> > > 
> > > Fixes: fdc915f7f719 ("tpm: expose spaces via a device link /dev/tpmrm")
> > > Signed-off-by: GUO Zihua <guozihua@xxxxxxxxxx>
> > >   drivers/char/tpm/tpm-chip.c | 13 +++++++++----
> > >   1 file changed, 9 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> > > index b009e7479b70..0a92334e8c40 100644
> > > +++ b/drivers/char/tpm/tpm-chip.c
> > > @@ -308,6 +308,12 @@ static int tpm_class_shutdown(struct device *dev)
> > >   	return 0;
> > >   }
> > > +static void tpm_chip_free(struct tpm_chip *chip)
> > > +{
> > > +	put_device(&chip->devs);
> > > +	put_device(&chip->dev);
> > > +}
> > > +
> > >   /**
> > >    * tpm_chip_alloc() - allocate a new struct tpm_chip instance
> > >    * @pdev: device to which the chip is associated
> > > @@ -396,8 +402,7 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
> > >   	return chip;
> > >   out:
> > > -	put_device(&chip->devs);
> > > -	put_device(&chip->dev);
> > > +	tpm_chip_free(chip);
> > >   	return ERR_PTR(rc);
> > >   }
> > >   EXPORT_SYMBOL_GPL(tpm_chip_alloc);
> > > @@ -420,8 +425,8 @@ struct tpm_chip *tpmm_chip_alloc(struct device *pdev,
> > >   		return chip;
> > >   	rc = devm_add_action_or_reset(pdev,
> > > -				      (void (*)(void *)) put_device,
> > > -				      &chip->dev);
> > > +				      (void (*)(void *)) tpm_chip_free,
> > > +				      chip);
> > >   	if (rc)
> > 
> > This looks like the same issue as was adressed by the recent discussion..
> > 
> > Jason
> > .
> 
> Hi Jason,
> 
> Would you mind refer me to the discussion?

Please test: git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git

And use tag tpmdd-next-v5.18-v2

If issues persists, let us know or send a fix.

BR, Jarkko