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FAILED: patch "[PATCH] mac80211: properly handle A-MSDUs that start with an RFC 1042" failed to apply to 4.14-stable tree

PATCH [email protected] 1 participant 1 message May 29, 2021

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Stable branch mac80211 802.11 (including cfg80211/NL80211)
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The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a1d5ff5651ea592c67054233b14b30bf4452999c Mon Sep 17 00:00:00 2001
From: Mathy Vanhoef <[email protected]>
Date: Tue, 11 May 2021 20:02:44 +0200
Subject: [PATCH] mac80211: properly handle A-MSDUs that start with an RFC 1042
header

Properly parse A-MSDUs whose first 6 bytes happen to equal a rfc1042 header. This can occur in practice when the destination MAC address equals AA:AA:03:00:00:00. More importantly, this simplifies the next patch to mitigate A-MSDU injection attacks.

Cc [email protected]
Signed-off-by Mathy Vanhoef <[email protected]>
Link https://lore.kernel.org/r/20210511200110.0b2b886492f0.I23dd5d685fe16d3b0ec8106e8f01b59f499dffed@changeid open here
Signed-off-by Johannes Berg <[email protected]>
include/net/cfg80211.h +2 -2
index 5224f885a99a..58c2cd417e89 100644
@@ -5760,7 +5760,7 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr);
  */
 int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 				  const u8 *addr, enum nl80211_iftype iftype,
-				  u8 data_offset);
+				  u8 data_offset, bool is_amsdu);
 
 /**
  * ieee80211_data_to_8023 - convert an 802.11 data frame to 802.3

@@ -5772,7 +5772,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 static inline int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
 					 enum nl80211_iftype iftype)
 {
-	return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype, 0);
+	return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype, 0, false);
 }
 
 /**
net/mac80211/rx.c +1 -1
index 531232b91bc4..f14d32a5001d 100644
@@ -2682,7 +2682,7 @@ __ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx, u8 data_offset)
 	if (ieee80211_data_to_8023_exthdr(skb, &ethhdr,
 					  rx->sdata->vif.addr,
 					  rx->sdata->vif.type,
-					  data_offset))
+					  data_offset, true))
 		return RX_DROP_UNUSABLE;
 
 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
net/wireless/util.c +2 -2
index 382c5262d997..39966a873e40 100644
@@ -542,7 +542,7 @@ EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen);
 
 int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 				  const u8 *addr, enum nl80211_iftype iftype,
-				  u8 data_offset)
+				  u8 data_offset, bool is_amsdu)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct {

@@ -629,7 +629,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 	skb_copy_bits(skb, hdrlen, &payload, sizeof(payload));
 	tmp.h_proto = payload.proto;
 
-	if (likely((ether_addr_equal(payload.hdr, rfc1042_header) &&
+	if (likely((!is_amsdu && ether_addr_equal(payload.hdr, rfc1042_header) &&
 		    tmp.h_proto != htons(ETH_P_AARP) &&
 		    tmp.h_proto != htons(ETH_P_IPX)) ||
 		   ether_addr_equal(payload.hdr, bridge_tunnel_header)))