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From ac70499ee97231a418dc1a4d6c9dc102e8f64631 Mon Sep 17 00:00:00 2001
From: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Date: Mon, 15 Apr 2019 16:45:04 +0300
Subject: [PATCH] iwlwifi: mvm: Drop large non sta frames
Git-commit: ac70499ee97231a418dc1a4d6c9dc102e8f64631
Patch-mainline: v5.3-rc1
References: bsc#1111666

In some buggy scenarios we could possible attempt to transmit frames larger
than maximum MSDU size. Since our devices don't know how to handle this,
it may result in asserts, hangs etc.
This can happen, for example, when we receive a large multicast frame
and try to transmit it back to the air in AP mode.
Since in a legal scenario this should never happen, drop such frames and
warn about it.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/intel/iwlwifi/mvm/tx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
index 16f7458e2e81..a3e5d88f1c07 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@@ -726,6 +726,9 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb)
 
 	memcpy(&info, skb->cb, sizeof(info));
 
+	if (WARN_ON_ONCE(skb->len > IEEE80211_MAX_DATA_LEN + hdrlen))
+		return -1;
+
 	if (WARN_ON_ONCE(info.flags & IEEE80211_TX_CTL_AMPDU))
 		return -1;
 
-- 
2.16.4