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
