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

[ Upstream commit 8e2f6f2366219b3304b227bdd2f04b64c92e3e12 ]

We want to guarantee the mutex is held for pretty much
all operations, so ensure that here as well.

Reported-by: syzbot+7e59a5bfc7a897247e18@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/wireless/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 0e08629b15d1d..abe7912a23760 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -202,7 +202,9 @@ static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
 {
 	struct cfg80211_registered_device *rdev = data;
 
+	wiphy_lock(&rdev->wiphy);
 	rdev_rfkill_poll(rdev);
+	wiphy_unlock(&rdev->wiphy);
 }
 
 void cfg80211_stop_p2p_device(struct cfg80211_registered_device *rdev,
-- 
2.42.0

On Mon, 2023-12-04 at 15:37 -0500, Sasha Levin wrote:
> 
> +++ b/net/wireless/core.c
> @@ -202,7 +202,9 @@ static void cfg80211_rfkill_poll(struct rfkill *rfkill, void *data)
>  {
>  	struct cfg80211_registered_device *rdev = data;
>  
> +	wiphy_lock(&rdev->wiphy);

This can't even _build_ on this old kernel?!

Anyway, my locking rework only went into 6.7, so this doesn't make sense
in any stable kernel, it's just not required.

johannes