mac80211: check defrag PN against current frame

commit bf30ca922a0c0176007e074b0acc77ed345e9990 upstream.

As pointed out by Mathy Vanhoef, we implement the RX PN check
on fragmented frames incorrectly - we check against the last
received PN prior to the new frame, rather than to the one in
this frame itself.

Prior patches addressed the security issue here, but in order
to be able to reason better about the code, fix it to really
compare against the current frame's PN, not the last stored
one.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.bfbc340ff071.Id0b690e581da7d03d76df90bb0e3fd55930bc8a0@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 6bfd31657f40ddfb3e6c6f903004993507ed6e5e..6c9d9c94983ba07ceb64a1506cbd55d1818f1fdb 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -225,8 +225,15 @@ struct ieee80211_rx_data {
         */
        int security_idx;
 
-       u32 tkip_iv32;
-       u16 tkip_iv16;
+       union {
+               struct {
+                       u32 iv32;
+                       u16 iv16;
+               } tkip;
+               struct {
+                       u8 pn[IEEE80211_CCMP_PN_LEN];
+               } ccm_gcm;
+       };
 };
 
 struct ieee80211_csa_settings {

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 21ce593c732bcb60056472da6282a952a447ab40..bfb9d9db8aff3363cee9ea4ec4a48e5df6f76b28 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2192,7 +2192,6 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
        if (entry->check_sequential_pn) {
                int i;
                u8 pn[IEEE80211_CCMP_PN_LEN], *rpn;
-               int queue;
 
                if (!requires_sequential_pn(rx, fc))
                        return RX_DROP_UNUSABLE;
@@ -2207,8 +2206,8 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
                        if (pn[i])
                                break;
                }
-               queue = rx->security_idx;
-               rpn = rx->key->u.ccmp.rx_pn[queue];
+
+               rpn = rx->ccm_gcm.pn;
                if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
                        return RX_DROP_UNUSABLE;
                memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);

diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 5dd48f0a4b1bd1d5eb24489f72a126a146639f4d..dbeccccf0fdf333fcb7684b08ac02e186f0f455c 100644 (file)
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -2,6 +2,7 @@
  * Copyright 2002-2004, Instant802 Networks, Inc.
  * Copyright 2008, Jouni Malinen <j@w1.fi>
  * Copyright (C) 2016-2017 Intel Deutschland GmbH
+ * Copyright (C) 2020-2021 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -170,8 +171,8 @@ ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
 
 update_iv:
        /* update IV in key information to be able to detect replays */
-       rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
-       rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
+       rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip.iv32;
+       rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip.iv16;
 
        return RX_CONTINUE;
 
@@ -297,8 +298,8 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
                                          key, skb->data + hdrlen,
                                          skb->len - hdrlen, rx->sta->sta.addr,
                                          hdr->addr1, hwaccel, rx->security_idx,
-                                         &rx->tkip_iv32,
-                                         &rx->tkip_iv16);
+                                         &rx->tkip.iv32,
+                                         &rx->tkip.iv16);
        if (res != TKIP_DECRYPT_OK)
                return RX_DROP_UNUSABLE;
 
@@ -556,6 +557,8 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
                }
 
                memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
+               if (unlikely(ieee80211_is_frag(hdr)))
+                       memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
        }
 
        /* Remove CCMP header and MIC */
@@ -784,6 +787,8 @@ ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
                }
 
                memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
+               if (unlikely(ieee80211_is_frag(hdr)))
+                       memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
        }
 
        /* Remove GCMP header and MIC */