On Mon, Nov 28, 2022 at 08:56:51PM +0100, Jason A. Donenfeld wrote: > From: Jan Dabros <jsd@xxxxxxxxxxxx> > > Currently tpm transactions are executed unconditionally in > tpm_pm_suspend() function, which may lead to races with other tpm > accessors in the system. Specifically, the hw_random tpm driver makes > use of tpm_get_random(), and this function is called in a loop from a > kthread, which means it's not frozen alongside userspace, and so can > race with the work done during system suspend: > > [ 3.277834] tpm tpm0: tpm_transmit: tpm_recv: error -52 > [ 3.278437] tpm tpm0: invalid TPM_STS.x 0xff, dumping stack for forensics > [ 3.278445] CPU: 0 PID: 1 Comm: init Not tainted 6.1.0-rc5+ #135 > [ 3.278450] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-20220807_005459-localhost 04/01/2014 > [ 3.278453] Call Trace: > [ 3.278458] <TASK> > [ 3.278460] dump_stack_lvl+0x34/0x44 > [ 3.278471] tpm_tis_status.cold+0x19/0x20 > [ 3.278479] tpm_transmit+0x13b/0x390 > [ 3.278489] tpm_transmit_cmd+0x20/0x80 > [ 3.278496] tpm1_pm_suspend+0xa6/0x110 > [ 3.278503] tpm_pm_suspend+0x53/0x80 > [ 3.278510] __pnp_bus_suspend+0x35/0xe0 > [ 3.278515] ? pnp_bus_freeze+0x10/0x10 > [ 3.278519] __device_suspend+0x10f/0x350 > > Fix this by calling tpm_try_get_ops(), which itself is a wrapper around > tpm_chip_start(), but takes the appropriate mutex. > > Signed-off-by: Jan Dabros <jsd@xxxxxxxxxxxx> > Reported-by: Vlastimil Babka <vbabka@xxxxxxx> > Tested-by: Jason A. Donenfeld <Jason@xxxxxxxxx> > Tested-by: Vlastimil Babka <vbabka@xxxxxxx> > Link: https://lore.kernel.org/all/c5ba47ef-393f-1fba-30bd-1230d1b4b592@xxxxxxx/ > Cc: stable@xxxxxxxxxxxxxxx > Fixes: e891db1a18bf ("tpm: turn on TPM on suspend for TPM 1.x") > [Jason: reworked commit message, added metadata] > Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> > --- > drivers/char/tpm/tpm-interface.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index 1621ce818705..d69905233aff 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -401,13 +401,14 @@ int tpm_pm_suspend(struct device *dev) > !pm_suspend_via_firmware()) > goto suspended; > > - if (!tpm_chip_start(chip)) { > + rc = tpm_try_get_ops(chip); > + if (!rc) { > if (chip->flags & TPM_CHIP_FLAG_TPM2) > tpm2_shutdown(chip, TPM2_SU_STATE); > else > rc = tpm1_pm_suspend(chip, tpm_suspend_pcr); > > - tpm_chip_stop(chip); > + tpm_put_ops(chip); > } > > suspended: > -- > 2.38.1 > Hi, sorry for the latency. Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> BR, Jarkko
