wifi: mac80211: fix potential key use-after-free

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@linaro.org>
Fixes: fdf7cb4185b6 ("mac80211: accept key reinstall without changing anything")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ 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@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 0c3da7771b48b13c0e99c8faa6f1d40b02d7a22c..c8d2fe8fbc0a3403dea58b7565bd89173e48a436 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -509,6 +509,9 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
                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);

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 6a72c33679ba90bbdac137e6f0c059e3d304af1c..6b089594a9f3fe344e6902d74df2ecfcf7b68c6f 100644 (file)
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -843,7 +843,7 @@ int ieee80211_key_link(struct ieee80211_key *key,
         */
        if (ieee80211_key_identical(sdata, old_key, key)) {
                ieee80211_key_free_unused(key);
-               ret = 0;
+               ret = -EALREADY;
                goto out;
        }