mac80211: do not access the IV when it was stripped

[ Upstream commit 77dfc2bc0bb4b8376ecd7a430f27a4a8fff6a5a0 ]

ieee80211_get_keyid() will return false value if IV has been stripped,
such as return 0 for IP/ARP frames due to LLC header, and return -EINVAL
for disassociation frames due to its length... etc. Don't try to access
it if it's not present.

Signed-off-by: Xing Song <xing.song@mediatek.com>
Link: https://lore.kernel.org/r/20211101024657.143026-1-xing.song@mediatek.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 419f06e..315a3e8 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1952,7 +1952,8 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
                int keyid = rx->sta->ptk_idx;
                sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
 
-               if (ieee80211_has_protected(fc)) {
+               if (ieee80211_has_protected(fc) &&
+                   !(status->flag & RX_FLAG_IV_STRIPPED)) {
                        cs = rx->sta->cipher_scheme;
                        keyid = ieee80211_get_keyid(rx->skb, cs);