linux-kernel - [PATCH] openvswitch: meter: Use 64-bit arithmetic instead of 32-bit

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Date:   Tue, 30 Jan 2018 22:55:33 -0600
From:   "Gustavo A. R. Silva" <gustavo@...eddedor.com>
To:     Pravin B Shelar <pshelar@....org>,
        "David S. Miller" <davem@...emloft.net>
Cc:     netdev@...r.kernel.org, dev@...nvswitch.org,
        linux-kernel@...r.kernel.org,
        "Gustavo A. R. Silva" <garsilva@...eddedor.com>
Subject: [PATCH] openvswitch: meter: Use 64-bit arithmetic instead of 32-bit

Add suffix LL to constant 1000 in order to give the compiler
complete information about the proper arithmetic to use. Notice
that this constant is used in a context that expects an expression
of type long long int (64 bits, signed).

The expression (band->burst_size + band->rate) * 1000 is currently
being evaluated using 32-bit arithmetic.

Addresses-Coverity-ID: 1461563 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavo@...eddedor.com>
---
 net/openvswitch/meter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
index 3fbfc78..04b9428 100644
--- a/net/openvswitch/meter.c
+++ b/net/openvswitch/meter.c
@@ -488,7 +488,7 @@ bool ovs_meter_execute(struct datapath *dp, struct sk_buff *skb,
 		long long int max_bucket_size;
 
 		band = &meter->bands[i];
-		max_bucket_size = (band->burst_size + band->rate) * 1000;
+		max_bucket_size = (band->burst_size + band->rate) * 1000LL;
 
 		band->bucket += delta_ms * band->rate;
 		if (band->bucket > max_bucket_size)
-- 
2.7.4