ath10k: drop fragments with multicast DA for PCIe

Fragmentation is not used with multicast frames. Discard unexpected
fragments with multicast DA. This fixes CVE-2020-26145.

Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00110-QCARMSWP-1

Cc: stable@vger.kernel.org
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20210511200110.5a0bd289bda8.Idd6ebea20038fb1cfee6de924aa595e5647c9eae@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index f1e5bce8b14f4e03100d55ec96a374ac69ffe9d2..cb04848ed5cb6ee1f433e3b520174a27ca2a7fdd 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -1768,6 +1768,16 @@ static u64 ath10k_htt_rx_h_get_pn(struct ath10k *ar, struct sk_buff *skb,
        return pn;
 }
 
+static bool ath10k_htt_rx_h_frag_multicast_check(struct ath10k *ar,
+                                                struct sk_buff *skb,
+                                                u16 offset)
+{
+       struct ieee80211_hdr *hdr;
+
+       hdr = (struct ieee80211_hdr *)(skb->data + offset);
+       return !is_multicast_ether_addr(hdr->addr1);
+}
+
 static bool ath10k_htt_rx_h_frag_pn_check(struct ath10k *ar,
                                          struct sk_buff *skb,
                                          u16 peer_id,
@@ -1839,7 +1849,7 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
        bool is_decrypted;
        bool is_mgmt;
        u32 attention;
-       bool frag_pn_check = true;
+       bool frag_pn_check = true, multicast_check = true;
 
        if (skb_queue_empty(amsdu))
                return;
@@ -1946,13 +1956,20 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
                                                                      0,
                                                                      enctype);
 
-               if (!frag_pn_check) {
-                       /* Discard the fragment with invalid PN */
+               if (frag)
+                       multicast_check = ath10k_htt_rx_h_frag_multicast_check(ar,
+                                                                              msdu,
+                                                                              0);
+
+               if (!frag_pn_check || !multicast_check) {
+                       /* Discard the fragment with invalid PN or multicast DA
+                        */
                        temp = msdu->prev;
                        __skb_unlink(msdu, amsdu);
                        dev_kfree_skb_any(msdu);
                        msdu = temp;
                        frag_pn_check = true;
+                       multicast_check = true;
                        continue;
                }