[PATCH][next] can: usb: fix potential integer overflow on shift of a int
From: Colin King <hidden>
Date: 2020-11-05 11:24:38
Also in:
kernel-janitors, linux-can, lkml
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
From: Colin Ian King <redacted>
The left shift of int 32 bit integer constant 1 is evaluated using
32 bit arithmetic and then assigned to a signed 64 bit variable. In
the case where time_ref->adapter->ts_used_bits is 32 or more this
can lead to an oveflow. Avoid this by shifting using the BIT_ULL macro
instead.
Addresses-Coverity: ("Unintentional integer overflow")
Fixes: bb4785551f64 ("can: usb: PEAK-System Technik USB adapters driver core")
Signed-off-by: Colin Ian King <redacted>
---
drivers/net/can/usb/peak_usb/pcan_usb_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_core.c b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
index c2764799f9ef..204ccb27d6d9 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c@@ -156,7 +156,7 @@ void peak_usb_get_ts_time(struct peak_time_ref *time_ref, u32 ts, ktime_t *time) if (time_ref->ts_dev_1 < time_ref->ts_dev_2) { /* case when event time (tsw) wraps */ if (ts < time_ref->ts_dev_1) - delta_ts = 1 << time_ref->adapter->ts_used_bits; + delta_ts = BIT_ULL(time_ref->adapter->ts_used_bits); /* Otherwise, sync time counter (ts_dev_2) has wrapped: * handle case when event time (tsn) hasn't.
@@ -168,7 +168,7 @@ void peak_usb_get_ts_time(struct peak_time_ref *time_ref, u32 ts, ktime_t *time) * tsn ts */ } else if (time_ref->ts_dev_1 < ts) { - delta_ts = -(1 << time_ref->adapter->ts_used_bits); + delta_ts = -BIT_ULL(time_ref->adapter->ts_used_bits); } /* add delay between last sync and event timestamps */
--
2.27.0