5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg <johannes.berg@xxxxxxxxx> commit 31db78a4923ef5e2008f2eed321811ca79e7f71b upstream. When ieee80211_key_link() is called by ieee80211_gtk_rekey_add() but returns 0 due to KRACK protection (identical key reinstall), ieee80211_gtk_rekey_add() will still return a pointer into the key, in a potential use-after-free. This normally doesn't happen since it's only called by iwlwifi in case of WoWLAN rekey offload which has its own KRACK protection, but still better to fix, do that by returning an error code and converting that to success on the cfg80211 boundary only, leaving the error for bad callers of ieee80211_gtk_rekey_add(). Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Fixes: fdf7cb4185b6 ("mac80211: accept key reinstall without changing anything") Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> [ Sherry: bp to fix CVE-2023-52530, resolved minor conflicts in net/mac80211/cfg.c because of context change due to missing commit 23a5f0af6ff4 ("wifi: mac80211: remove cipher scheme support") ccdde7c74ffd ("wifi: mac80211: properly implement MLO key handling")] Signed-off-by: Sherry Yang <sherry.yang@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/mac80211/cfg.c | 3 +++ net/mac80211/key.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -491,6 +491,9 @@ static int ieee80211_add_key(struct wiph sta->cipher_scheme = cs; err = ieee80211_key_link(key, sdata, sta); + /* KRACK protection, shouldn't happen but just silently accept key */ + if (err == -EALREADY) + err = 0; out_unlock: mutex_unlock(&local->sta_mtx); --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -808,7 +808,7 @@ int ieee80211_key_link(struct ieee80211_ */ if (ieee80211_key_identical(sdata, old_key, key)) { ieee80211_key_free_unused(key); - ret = 0; + ret = -EALREADY; goto out; }