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From:   Colin King <colin.king@canonical.com>
To:     Jiri Pirko <jiri@mellanox.com>, Ido Schimmel <idosch@mellanox.com>,
        "David S . Miller" <davem@davemloft.net>, netdev@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] mlxsw: spectrum_trap: fix unintention integer overflow on left shift
Date:   Thu,  2 Apr 2020 15:48:51 +0100
Message-Id: <20200402144851.565983-1-colin.king@canonical.com>
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From: Colin Ian King <colin.king@canonical.com>

Shifting the integer value 1 is evaluated using 32-bit
arithmetic and then used in an expression that expects a 64-bit
value, so there is potentially an integer overflow. Fix this
by using the BIT_ULL macro to perform the shift and avoid the
overflow.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: 13f2e64b94ea ("mlxsw: spectrum_trap: Add devlink-trap policer support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
index 9096ffd89e50..fbf714d027d8 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
@@ -643,7 +643,7 @@ static int mlxsw_sp_trap_policer_bs(u64 burst, u8 *p_burst_size,
 {
 	int bs = fls64(burst) - 1;
 
-	if (burst != (1 << bs)) {
+	if (burst != (BIT_ULL(bs))) {
 		NL_SET_ERR_MSG_MOD(extack, "Policer burst size is not power of two");
 		return -EINVAL;
 	}
-- 
2.25.1