From 9c167b2ddc1a89e6f6378e65bfd20e8c0ddf65f1 Mon Sep 17 00:00:00 2001
From: Julian Squires <julian@cipht.net>
Date: Mon, 20 Jul 2020 12:20:35 -0230
Subject: [PATCH] cfg80211: allow vendor dumpit to terminate by returning 0
Git-commit: 9c167b2ddc1a89e6f6378e65bfd20e8c0ddf65f1
Patch-mainline: v5.9-rc1
References: jsc#SLE-13430

nl80211 vendor netlink dumpit, like netlink_callback->dump, should
signal successful completion by returning 0.

Currently, that will just cause dumpit to be called again, possibly
many times until an error occurs.  Since skb->len is never going to be
0 by the time dumpit is called, the only way for dumpit to signal
completion is by returning an error.  If it returns a positive value,
the current message is cancelled, but that positive value is returned
and nl80211_vendor_cmd_dump gets called again.

Fix that by passing a return value of 0 through.

Signed-off-by: Julian Squires <julian@cipht.net>
Link: https://lore.kernel.org/r/20200720145033.401307-1-julian@cipht.net
[reword commit message]

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/wireless/nl80211.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0e07fb8585fb..e9cf08a1a8b9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -13479,7 +13479,7 @@ static int nl80211_vendor_cmd_dump(struct sk_buff *skb,
 		if (err == -ENOBUFS || err == -ENOENT) {
 			genlmsg_cancel(skb, hdr);
 			break;
-		} else if (err) {
+		} else if (err <= 0) {
 			genlmsg_cancel(skb, hdr);
 			goto out;
 		}
-- 
2.16.4