[lvc-project] [PATCH v2] comedi: drivers: ni_tio: Fix arithmetic expression overflow

[Denis Arefev]

The value of an arithmetic expression period_ns * 1000 is subject
to overflow due to a failure to cast operands to a larger data
type before performing arithmetic

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 3e90b1c7ebe9 ("staging: comedi: ni_tio: tidy up ni_tio_set_clock_src() and helpers")
Cc: <stable at vger.kernel.org> # v5.15+ 
Reviewed-by: Ian Abbott <abbotti at mev.co.uk>
Signed-off-by: Denis Arefev <arefev at swemel.ru>
Signed-off-by: Ian Abbott <abbotti at mev.co.uk>
---
 V1 -> V2: Oh, good point.  It should be 1000ULL.
 drivers/comedi/drivers/ni_tio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/comedi/drivers/ni_tio.c b/drivers/comedi/drivers/ni_tio.c
index da6826d77e60..acc914903c70 100644
--- a/drivers/comedi/drivers/ni_tio.c
+++ b/drivers/comedi/drivers/ni_tio.c
@@ -800,7 +800,7 @@ static int ni_tio_set_clock_src(struct ni_gpct *counter,
 				GI_PRESCALE_X2(counter_dev->variant) |
 				GI_PRESCALE_X8(counter_dev->variant), bits);
 	}
-	counter->clock_period_ps = period_ns * 1000;
+	counter->clock_period_ps = period_ns * 1000ULL;
 	ni_tio_set_sync_mode(counter);
 	return 0;
 }
-- 
2.25.1