ath11k: Drop multicast fragments

Fragmentation is used only with unicast frames. Drop multicast fragments
to avoid any undesired behavior.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.4.0.1-01734-QCAHKSWPL_SILICONZ-1 v2

Cc: stable@vger.kernel.org
Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20210511200110.1d53bfd20a8b.Ibb63283051bb5e2c45951932c6e1f351d5a73dc3@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/ath/ath11k/dp_rx.c

@@ -260,6 +260,16 @@ static void ath11k_dp_rxdesc_set_msdu_len(struct ath11k_base *ab,
 	ab->hw_params.hw_ops->rx_desc_set_msdu_len(desc, len);
 }
 
+static bool ath11k_dp_rx_h_attn_is_mcbc(struct ath11k_base *ab,
+					struct hal_rx_desc *desc)
+{
+	struct rx_attention *attn = ath11k_dp_rx_get_attention(ab, desc);
+
+	return ath11k_dp_rx_h_msdu_end_first_msdu(ab, desc) &&
+		(!!FIELD_GET(RX_ATTENTION_INFO1_MCAST_BCAST,
+		 __le32_to_cpu(attn->info1)));
+}
+
 static void ath11k_dp_service_mon_ring(struct timer_list *t)
 {
 	struct ath11k_base *ab = from_timer(ab, t, mon_reap_timer);
@@ -3468,6 +3478,7 @@ static int ath11k_dp_rx_frag_h_mpdu(struct ath11k *ar,
 	u8 tid;
 	int ret = 0;
 	bool more_frags;
+	bool is_mcbc;
 
 	rx_desc = (struct hal_rx_desc *)msdu->data;
 	peer_id = ath11k_dp_rx_h_mpdu_start_peer_id(ar->ab, rx_desc);
@@ -3475,6 +3486,11 @@ static int ath11k_dp_rx_frag_h_mpdu(struct ath11k *ar,
 	seqno = ath11k_dp_rx_h_mpdu_start_seq_no(ar->ab, rx_desc);
 	frag_no = ath11k_dp_rx_h_mpdu_start_frag_no(ar->ab, msdu);
 	more_frags = ath11k_dp_rx_h_mpdu_start_more_frags(ar->ab, msdu);
+	is_mcbc = ath11k_dp_rx_h_attn_is_mcbc(ar->ab, rx_desc);
+
+	/* Multicast/Broadcast fragments are not expected */
+	if (is_mcbc)
+		return -EINVAL;
 
 	if (!ath11k_dp_rx_h_mpdu_start_seq_ctrl_valid(ar->ab, rx_desc) ||
 	    !ath11k_dp_rx_h_mpdu_start_fc_valid(ar->ab, rx_desc) ||