Re: UBSAN: Undefined behaviour in net/wireless/nl80211.c:718:4: -1665903437 * 100 cannot be represented in type 'int'

[Johannes Berg <johannes@sipsolutions.net>]

Hi,

Can you reproduce this?

> [   54.426491] UBSAN: Undefined behaviour in net/wireless/nl80211.c:718:4
> [   54.426492] signed integer overflow:
> [   54.426493] -1665903437 * 100 cannot be represented in type 'int'

Obviously.

However, it looks like the real reason is that there's some garbage (-
1665903437) in chan->max_power, which is just stack memory being leaked
out...

This should help?

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 78e71b0390be..7b42f0bacfd8 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1769,8 +1769,7 @@ static void handle_reg_beacon(struct wiphy *wiphy, unsigned int chan_idx,
 	if (wiphy->regulatory_flags & REGULATORY_DISABLE_BEACON_HINTS)
 		return;
 
-	chan_before.center_freq = chan->center_freq;
-	chan_before.flags = chan->flags;
+	chan_before = *chan;
 
 	if (chan->flags & IEEE80211_CHAN_NO_IR) {
 		chan->flags &= ~IEEE80211_CHAN_NO_IR;

johannes