[PATCH] wifi: cfg80211: Fix error pointer dereference in nl80211_pre_doit()

[Ethan Tidmore]

nl80211_lock_and_recheck() can return an ERR_PTR on failure. If this
happens, 'wdev' holds an error pointer that bypasses the non-NULL
check at 'out' and gets passed into wdev_put(), resulting in a
dereference. Clear 'wdev' to NULL before jumping to 'out' to prevent
this.

Fixes: 8e3d9039d280 ("wifi: nl80211: avoid rtnl for commands that don't want it")
Signed-off-by: Ethan Tidmore <ethantidmore06@xxxxxxxxx>
---
 net/wireless/nl80211.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index d790e204aee3..7a5f7000fbaa 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -20192,6 +20192,7 @@ static int nl80211_pre_doit(const struct genl_split_ops *ops,
 			wdev = nl80211_lock_and_recheck(rdev, netns, wdev_id);
 			if (IS_ERR(wdev)) {
 				err = PTR_ERR(wdev);
+				wdev = NULL;
 				goto out;
 			}
 		}
-- 
Thanks,
ET
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