From: Colin Ian King Date: Tue, 8 May 2018 12:57:32 +0000 (+0100) Subject: mac80211: ethtool: avoid 32 bit multiplication overflow X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=57c6cb81717f957fb741f2e4c79bd0e2f4f55910;p=linux.git mac80211: ethtool: avoid 32 bit multiplication overflow 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 Signed-off-by: Johannes Berg --- diff --git a/net/mac80211/ethtool.c b/net/mac80211/ethtool.c index 1afeff94af8ba..09210aa8ea9ad 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++;