Commit c503b128 authored Nov 05, 2020 by Colin Ian King Committed by Greg Kroah-Hartman Nov 24, 2020

can: peak_usb: fix potential integer overflow on shift of a int



[ Upstream commit 8a68cc0d690c9e5730d676b764c6f059343b842c ]

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.

Fixes: bb478555 ("can: usb: PEAK-System Technik USB adapters driver core")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20201105112427.40688-1-colin.king@canonical.com


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent f823134f

drivers/net/can/usb/peak_usb/pcan_usb_core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -178,7 +178,7 @@ void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts,
		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.
		@@ -190,7 +190,7 @@ void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts,
		* 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 */