Re: [PATCH v2] tpm: Fix null pointer dereference on chip register error path

[Jarkko Sakkinen]

On Mon, 2019-07-08 at 17:34 +0300, Jarkko Sakkinen wrote:
> On Thu, 2019-07-04 at 09:26 +0200, Milan Broz wrote:
> > If clk_enable is not defined and chip initialization
> > is canceled code hits null dereference.
> > 
> > Easily reproducible with vTPM init fail:
> >   swtpm chardev --tpmstate dir=nonexistent_dir --tpm2 --vtpm-proxy
> > 
> > BUG: kernel NULL pointer dereference, address: 00000000
> > ...
> > Call Trace:
> >  tpm_chip_start+0x9d/0xa0 [tpm]
> >  tpm_chip_register+0x10/0x1a0 [tpm]
> >  vtpm_proxy_work+0x11/0x30 [tpm_vtpm_proxy]
> >  process_one_work+0x214/0x5a0
> >  worker_thread+0x134/0x3e0
> >  ? process_one_work+0x5a0/0x5a0
> >  kthread+0xd4/0x100
> >  ? process_one_work+0x5a0/0x5a0
> >  ? kthread_park+0x90/0x90
> >  ret_from_fork+0x19/0x24
> > 
> > Fixes: 719b7d81f204 ("tpm: introduce tpm_chip_start() and tpm_chip_stop()")
> > Cc: stable@xxxxxxxxxxxxxxx # v5.1+
> > Signed-off-by: Milan Broz <gmazyland@xxxxxxxxx>
> 
> Looks legit.
> 
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>

Please check master and next branches from

  git://git.infradead.org/users/jjs/linux-tpmdd.git

/Jarkko