netdev - [PATCH] wifi: cfg80211: silence a sparse RCU warning

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Message-Id: <20221013194149.532913e897bd.I4e49ca6ce4248c0c4a9fa8c78e48ad91ab80c31c@changeid>
Date:   Thu, 13 Oct 2022 19:41:51 +0200
From:   Johannes Berg <johannes@...solutions.net>
To:     linux-wireless@...r.kernel.org
Cc:     netdev@...r.kernel.org, Jakub Kicinski <kuba@...nel.org>,
        Johannes Berg <johannes.berg@...el.com>
Subject: [PATCH] wifi: cfg80211: silence a sparse RCU warning

From: Johannes Berg <johannes.berg@...el.com>

All we're going to do with this pointer is assign it to
another __rcu pointer, but sparse can't see that, so
use rcu_access_pointer() to silence the warning here.

Fixes: c90b93b5b782 ("wifi: cfg80211: update hidden BSSes to avoid WARN_ON")
Signed-off-by: Johannes Berg <johannes.berg@...el.com>
---
Sending it now anyway, just in case you might want to
throw it into the tree before sending a PR to Linus.
---
 net/wireless/scan.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 806a5f1330ff..da752b0cc752 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1674,7 +1674,9 @@ cfg80211_update_known_bss(struct cfg80211_registered_device *rdev,
 		if (old == rcu_access_pointer(known->pub.ies))
 			rcu_assign_pointer(known->pub.ies, new->pub.beacon_ies);
 
-		cfg80211_update_hidden_bsses(known, new->pub.beacon_ies, old);
+		cfg80211_update_hidden_bsses(known,
+					     rcu_access_pointer(new->pub.beacon_ies),
+					     old);
 
 		if (old)
 			kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
-- 
2.37.3