[openwrt/openwrt] mac80211: fix issues with receiving small STP packets

LEDE Commits lede-commits at lists.infradead.org
Fri Oct 7 02:32:08 PDT 2022


nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/cec7dfa49775ce65270b977bea5fc0f928f97bdc

commit cec7dfa49775ce65270b977bea5fc0f928f97bdc
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Fri Oct 7 11:29:54 2022 +0200

    mac80211: fix issues with receiving small STP packets
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 ...11-fix-ieee80211_data_to_8023_exthdr-hand.patch | 97 ++++++++++++++++++++++
 ...11-do-not-drop-packets-smaller-than-the-L.patch | 25 ++++++
 2 files changed, 122 insertions(+)

diff --git a/package/kernel/mac80211/patches/subsys/344-wifi-cfg80211-fix-ieee80211_data_to_8023_exthdr-hand.patch b/package/kernel/mac80211/patches/subsys/344-wifi-cfg80211-fix-ieee80211_data_to_8023_exthdr-hand.patch
new file mode 100644
index 0000000000..220de79d9e
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/344-wifi-cfg80211-fix-ieee80211_data_to_8023_exthdr-hand.patch
@@ -0,0 +1,97 @@
+From: Felix Fietkau <nbd at nbd.name>
+Date: Fri, 7 Oct 2022 10:54:47 +0200
+Subject: [PATCH] wifi: cfg80211: fix ieee80211_data_to_8023_exthdr
+ handling of small packets
+
+STP topology change notification packets only have a payload of 7 bytes,
+so they get dropped due to the skb->len < hdrlen + 8 check.
+Fix this by removing skb->len based checks and instead check the return code
+on the skb_copy_bits calls.
+
+Fixes: 2d1c304cb2d5 ("cfg80211: add function for 802.3 conversion with separate output buffer")
+Reported-by: Chad Monroe <chad.monroe at smartrg.com>
+Signed-off-by: Felix Fietkau <nbd at nbd.name>
+---
+
+--- a/net/wireless/util.c
++++ b/net/wireless/util.c
+@@ -557,8 +557,6 @@ int ieee80211_data_to_8023_exthdr(struct
+ 		return -1;
+ 
+ 	hdrlen = ieee80211_hdrlen(hdr->frame_control) + data_offset;
+-	if (skb->len < hdrlen + 8)
+-		return -1;
+ 
+ 	/* convert IEEE 802.11 header + possible LLC headers into Ethernet
+ 	 * header
+@@ -572,8 +570,9 @@ int ieee80211_data_to_8023_exthdr(struct
+ 	memcpy(tmp.h_dest, ieee80211_get_DA(hdr), ETH_ALEN);
+ 	memcpy(tmp.h_source, ieee80211_get_SA(hdr), ETH_ALEN);
+ 
+-	if (iftype == NL80211_IFTYPE_MESH_POINT)
+-		skb_copy_bits(skb, hdrlen, &mesh_flags, 1);
++	if (iftype == NL80211_IFTYPE_MESH_POINT &&
++	    skb_copy_bits(skb, hdrlen, &mesh_flags, 1) < 0)
++		return -1;
+ 
+ 	mesh_flags &= MESH_FLAGS_AE;
+ 
+@@ -593,11 +592,12 @@ int ieee80211_data_to_8023_exthdr(struct
+ 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
+ 			if (mesh_flags == MESH_FLAGS_AE_A4)
+ 				return -1;
+-			if (mesh_flags == MESH_FLAGS_AE_A5_A6) {
+-				skb_copy_bits(skb, hdrlen +
+-					offsetof(struct ieee80211s_hdr, eaddr1),
+-					tmp.h_dest, 2 * ETH_ALEN);
+-			}
++			if (mesh_flags == MESH_FLAGS_AE_A5_A6 &&
++			    skb_copy_bits(skb, hdrlen +
++					  offsetof(struct ieee80211s_hdr, eaddr1),
++					  tmp.h_dest, 2 * ETH_ALEN) < 0)
++				return -1;
++
+ 			hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);
+ 		}
+ 		break;
+@@ -611,10 +611,11 @@ int ieee80211_data_to_8023_exthdr(struct
+ 		if (iftype == NL80211_IFTYPE_MESH_POINT) {
+ 			if (mesh_flags == MESH_FLAGS_AE_A5_A6)
+ 				return -1;
+-			if (mesh_flags == MESH_FLAGS_AE_A4)
+-				skb_copy_bits(skb, hdrlen +
+-					offsetof(struct ieee80211s_hdr, eaddr1),
+-					tmp.h_source, ETH_ALEN);
++			if (mesh_flags == MESH_FLAGS_AE_A4 &&
++			    skb_copy_bits(skb, hdrlen +
++					  offsetof(struct ieee80211s_hdr, eaddr1),
++					  tmp.h_source, ETH_ALEN) < 0)
++				return -1;
+ 			hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);
+ 		}
+ 		break;
+@@ -626,18 +627,18 @@ int ieee80211_data_to_8023_exthdr(struct
+ 		break;
+ 	}
+ 
+-	skb_copy_bits(skb, hdrlen, &payload, sizeof(payload));
+-	tmp.h_proto = payload.proto;
+-
+-	if (likely((!is_amsdu && ether_addr_equal(payload.hdr, rfc1042_header) &&
++	if (likely(skb_copy_bits(skb, hdrlen, &payload, sizeof(payload)) == 0) &&
++	    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)))
++		   ether_addr_equal(payload.hdr, bridge_tunnel_header))) {
+ 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
+ 		 * replace EtherType */
+ 		hdrlen += ETH_ALEN + 2;
+-	else
++		tmp.h_proto = payload.proto;
++	} else {
+ 		tmp.h_proto = htons(skb->len - hdrlen);
++	}
+ 
+ 	pskb_pull(skb, hdrlen);
+ 
diff --git a/package/kernel/mac80211/patches/subsys/345-wifi-mac80211-do-not-drop-packets-smaller-than-the-L.patch b/package/kernel/mac80211/patches/subsys/345-wifi-mac80211-do-not-drop-packets-smaller-than-the-L.patch
new file mode 100644
index 0000000000..16cafc447c
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/345-wifi-mac80211-do-not-drop-packets-smaller-than-the-L.patch
@@ -0,0 +1,25 @@
+From: Felix Fietkau <nbd at nbd.name>
+Date: Fri, 7 Oct 2022 10:58:26 +0200
+Subject: [PATCH] wifi: mac80211: do not drop packets smaller than the
+ LLC-SNAP header on fast-rx
+
+Since STP TCN frames are only 7 bytes, the pskb_may_pull call returns an error.
+Instead of dropping those packets, bump them back to the slow path for proper
+processing.
+
+Fixes: 49ddf8e6e234 ("mac80211: add fast-rx path")
+Reported-by: Chad Monroe <chad.monroe at smartrg.com>
+Signed-off-by: Felix Fietkau <nbd at nbd.name>
+---
+
+--- a/net/mac80211/rx.c
++++ b/net/mac80211/rx.c
+@@ -4601,7 +4601,7 @@ static bool ieee80211_invoke_fast_rx(str
+ 
+ 	if (!(status->rx_flags & IEEE80211_RX_AMSDU)) {
+ 		if (!pskb_may_pull(skb, snap_offs + sizeof(*payload)))
+-			goto drop;
++			return false;
+ 
+ 		payload = (void *)(skb->data + snap_offs);
+ 




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