[PATCH 4.9 04/39] cfg80211: fix cfg80211_beacon_dup

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann <arnd@xxxxxxxx>

commit bee92d06157fc39d5d7836a061c7d41289a55797 upstream.

gcc-8 warns about some obviously incorrect code:

net/mac80211/cfg.c: In function 'cfg80211_beacon_dup':
net/mac80211/cfg.c:2896:3: error: 'memcpy' source argument is the same as destination [-Werror=restrict]

>From the context, I conclude that we want to copy from beacon into
new_beacon, as we do in the rest of the function.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 73da7d5bab79 ("mac80211: add channel switch command and beacon callbacks")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/mac80211/cfg.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2792,7 +2792,7 @@ cfg80211_beacon_dup(struct cfg80211_beac
 	}
 	if (beacon->probe_resp_len) {
 		new_beacon->probe_resp_len = beacon->probe_resp_len;
-		beacon->probe_resp = pos;
+		new_beacon->probe_resp = pos;
 		memcpy(pos, beacon->probe_resp, beacon->probe_resp_len);
 		pos += beacon->probe_resp_len;
 	}