mac80211: prevent attacks on TKIP/WEP as well

commit 7e44a0b597f04e67eee8cdcbe7ee706c6f5de38b upstream.

Similar to the issues fixed in previous patches, TKIP and WEP
should be protected even if for TKIP we have the Michael MIC
protecting it, and WEP is broken anyway.

However, this also somewhat protects potential other algorithms
that drivers might implement.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.430e8c202313.Ia37e4e5b6b3eaab1a5ae050e015f6c92859dbe27@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 350b2035f37a7ce98e779474343bdee94aaf8aa6..7f070b911b2ab05cba6a20e6da4340125deec689 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1888,6 +1888,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
                         * next fragment has a sequential PN value.
                         */
                        entry->check_sequential_pn = true;
+                       entry->is_protected = true;
                        entry->key_color = rx->key->color;
                        memcpy(entry->last_pn,
                               rx->key->u.ccmp.rx_pn[queue],
@@ -1900,6 +1901,9 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
                                     sizeof(rx->key->u.gcmp.rx_pn[queue]));
                        BUILD_BUG_ON(IEEE80211_CCMP_PN_LEN !=
                                     IEEE80211_GCMP_PN_LEN);
+               } else if (rx->key && ieee80211_has_protected(fc)) {
+                       entry->is_protected = true;
+                       entry->key_color = rx->key->color;
                }
                return RX_QUEUED;
        }
@@ -1941,6 +1945,14 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
                if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
                        return RX_DROP_UNUSABLE;
                memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
+       } else if (entry->is_protected &&
+                  (!rx->key || !ieee80211_has_protected(fc) ||
+                   rx->key->color != entry->key_color)) {
+               /* Drop this as a mixed key or fragment cache attack, even
+                * if for TKIP Michael MIC should protect us, and WEP is a
+                * lost cause anyway.
+                */
+               return RX_DROP_UNUSABLE;
        }
 
        skb_pull(rx->skb, ieee80211_hdrlen(fc));

diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 1b178cc42d3a3103bd120ddcedb376d8bb605dcf..b2e5928b1f7b58c60bad406b8376ea15d55ae2df 100644 (file)
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -341,7 +341,8 @@ struct ieee80211_fragment_entry {
        u16 extra_len;
        u16 last_frag;
        u8 rx_queue;
-       bool check_sequential_pn; /* needed for CCMP/GCMP */
+       u8 check_sequential_pn:1, /* needed for CCMP/GCMP */
+          is_protected:1;
        u8 last_pn[6]; /* PN of the last fragment if CCMP was used */
        unsigned int key_color;
 };