[lvc-project] [PATCH 6.1] wifi: mac80211: avoid lockdep checking when removing deflink

[Alexander Ofitserov]

From: Benjamin Berg <benjamin.berg ÎÁ intel.com>

[ Upstream commit b8b80770b26c4591f20f1cde3328e5f1489c4488 ]

struct sta_info may be removed without holding sta_mtx if it has not
yet been inserted. To support this, only assert that the lock is held
for links other than the deflink.

This fixes lockdep issues that may be triggered in error cases.

Signed-off-by: Benjamin Berg <benjamin.berg ÎÁ intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman ÎÁ intel.com>
Link: https://lore.kernel.org/r/20230619161906.cdd81377dea0.If5a6734b4b85608a2275a09b4f99b5564d82997f@changeid
Signed-off-by: Johannes Berg <johannes.berg ÎÁ intel.com>
Signed-off-by: Alexander Ofitserov <oficerovas ÎÁ altlinux.org>
Cc: stable ÎÁ vger.kernel.org
---
 net/mac80211/sta_info.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index bd56015b29258..edec857edbd25 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -357,8 +357,9 @@ static void sta_remove_link(struct sta_info *sta, unsigned int link_id,
 	struct sta_link_alloc *alloc = NULL;
 	struct link_sta_info *link_sta;
 
-	link_sta = rcu_dereference_protected(sta->link[link_id],
-					     lockdep_is_held(&sta->local->sta_mtx));
+	link_sta = rcu_access_pointer(sta->link[link_id]);
+	if (link_sta != &sta->deflink)
+		lockdep_assert_held(&sta->local->sta_mtx);
 
 	if (WARN_ON(!link_sta))
 		return;
-- 
2.42.1