From 57c6cb81717f957fb741f2e4c79bd0e2f4f55910 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Tue, 8 May 2018 13:57:32 +0100
Subject: [PATCH] mac80211: ethtool: avoid 32 bit multiplication overflow
Git-commit: 57c6cb81717f957fb741f2e4c79bd0e2f4f55910
Patch-mainline: v4.18-rc1
References: FATE#326294

The multiplication of 100000 * cfg80211_calculate_bitrate() is a 32 bit
operation and can overflow if cfg80211_calculate_bitrate is greater
than 42949. Although I don't believe this is occurring at present, it
would be safer to avoid the potential overflow by making the constant
100000 an ULL to ensure a 64 multiplication occurs.

Detected by CoverityScan, CID#1468643 ("Unintentional integer overflow")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/mac80211/ethtool.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/ethtool.c b/net/mac80211/ethtool.c
index 1afeff94af8b..09210aa8ea9a 100644
--- a/net/mac80211/ethtool.c
+++ b/net/mac80211/ethtool.c
@@ -121,11 +121,11 @@ static void ieee80211_get_stats(struct net_device *dev,
 
 
 		if (sinfo->filled & BIT(NL80211_STA_INFO_TX_BITRATE))
-			data[i] = 100000 *
+			data[i] = 100000ULL *
 				cfg80211_calculate_bitrate(&sinfo->txrate);
 		i++;
 		if (sinfo->filled & BIT(NL80211_STA_INFO_RX_BITRATE))
-			data[i] = 100000 *
+			data[i] = 100000ULL *
 				cfg80211_calculate_bitrate(&sinfo->rxrate);
 		i++;
 
-- 
2.19.2