[PATCH 4.19 072/120] liquidio: Fix unintentional sign extension issue on left shift of u16

Greg Kroah-Hartman
2021-07-26T16:06:00Z

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit e7efc2ce3d0789cd7c21b70ff00cd7838d382639 ]

Shifting the u16 integer oct->pcie_port by CN23XX_PKT_INPUT_CTL_MAC_NUM_POS
(29) bits will be promoted to a 32 bit signed int and then sign-extended
to a u64. In the cases where oct->pcie_port where bit 2 is set (e.g. 3..7)
the shifted value will be sign extended and the top 32 bits of the result
will be set.

Fix this by casting the u16 values to a u64 before the 29 bit left shift.

Addresses-Coverity: ("Unintended sign extension")

Fixes: 3451b97cce2d ("liquidio: CN23XX register setup")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c b/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c
index 55fe80ca10d3..9e447983d0aa 100644
--- a/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c
+++ b/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c
@@ -420,7 +420,7 @@ static int cn23xx_pf_setup_global_input_regs(struct octeon_device *oct)
* bits 32:47 indicate the PVF num.
*/
for (q_no = 0; q_no < ern; q_no++) {
- reg_val = oct->pcie_port << CN23XX_PKT_INPUT_CTL_MAC_NUM_POS;
+ reg_val = (u64)oct->pcie_port << CN23XX_PKT_INPUT_CTL_MAC_NUM_POS;

/* for VF assigned queues. */
if (q_no < oct->sriov_info.pf_srn) {
--
2.30.2