This is a note to let you know that I've just added the patch titled can: peak_usb: fix potential integer overflow on shift of a int to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: can-peak_usb-fix-potential-integer-overflow-on-shift.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 060e98ffbac4b4cd3692c2dacaa36bbc87399b48 Author: Colin Ian King <colin.king@xxxxxxxxxxxxx> Date: Thu Nov 5 11:24:27 2020 +0000 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: bb4785551f64 ("can: usb: PEAK-System Technik USB adapters driver core") Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20201105112427.40688-1-colin.king@xxxxxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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 c2764799f9efb..204ccb27d6d9a 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 */