[PATCH][V2] net: lio_core: fix potential sign-extension overflow on large shift

From: Colin King
Date: Mon Jun 17 2019 - 12:17:50 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Left shifting the signed int value 1 by 31 bits has undefined behaviour
and the shift amount oq_no can be as much as 63. Fix this by using
BIT_ULL(oq_no) instead.

Addresses-Coverity: ("Bad shift operation")
Fixes: f21fb3ed364b ("Add support of Cavium Liquidio ethernet adapters")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---

V2: Use BIT_ULL(oq_no) instead of 1ULL << oq_no. Thanks to Dan Carpenter for
noting this is more appropriate.

---
drivers/net/ethernet/cavium/liquidio/lio_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_core.c b/drivers/net/ethernet/cavium/liquidio/lio_core.c
index 1c50c10b5a16..d7e805749a5b 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_core.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_core.c
@@ -964,7 +964,7 @@ static void liquidio_schedule_droq_pkt_handlers(struct octeon_device *oct)

if (droq->ops.poll_mode) {
droq->ops.napi_fn(droq);
- oct_priv->napi_mask |= (1 << oq_no);
+ oct_priv->napi_mask |= BIT_ULL(oq_no);
} else {
tasklet_schedule(&oct_priv->droq_tasklet);
}
--
2.20.1