[PATCH AUTOSEL 5.4 05/18] mac80211: allow rx of mesh eapol frames with default rx key

* [PATCH AUTOSEL 5.4 05/18] mac80211: allow rx of mesh eapol frames with default rx key
       [not found] <20200714143914.4035489-1-sashal@kernel.org>
@ 2020-07-14 14:39 ` Sasha Levin
  2020-07-14 14:39 ` [PATCH AUTOSEL 5.4 10/18] drivers/net/wan/lapbether: Fixed the value of hard_header_len Sasha Levin
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2020-07-14 14:39 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Markus Theil, Johannes Berg, Sasha Levin, linux-wireless, netdev

From: Markus Theil <markus.theil@tu-ilmenau.de>

[ Upstream commit 0b467b63870d9c05c81456aa9bfee894ab2db3b6 ]

Without this patch, eapol frames cannot be received in mesh
mode, when 802.1X should be used. Initially only a MGTK is
defined, which is found and set as rx->key, when there are
no other keys set. ieee80211_drop_unencrypted would then
drop these eapol frames, as they are data frames without
encryption and there exists some rx->key.

Fix this by differentiating between mesh eapol frames and
other data frames with existing rx->key. Allow mesh mesh
eapol frames only if they are for our vif address.

With this patch in-place, ieee80211_rx_h_mesh_fwding continues
after the ieee80211_drop_unencrypted check and notices, that
these eapol frames have to be delivered locally, as they should.

Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Link: https://lore.kernel.org/r/20200625104214.50319-1-markus.theil@tu-ilmenau.de
[small code cleanups]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mac80211/rx.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 69429c8df7b30..e5fb9002d3147 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2305,6 +2305,7 @@ static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
 
 static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
 {
+	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
 	struct sk_buff *skb = rx->skb;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 
@@ -2315,6 +2316,31 @@ static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
 	if (status->flag & RX_FLAG_DECRYPTED)
 		return 0;
 
+	/* check mesh EAPOL frames first */
+	if (unlikely(rx->sta && ieee80211_vif_is_mesh(&rx->sdata->vif) &&
+		     ieee80211_is_data(fc))) {
+		struct ieee80211s_hdr *mesh_hdr;
+		u16 hdr_len = ieee80211_hdrlen(fc);
+		u16 ethertype_offset;
+		__be16 ethertype;
+
+		if (!ether_addr_equal(hdr->addr1, rx->sdata->vif.addr))
+			goto drop_check;
+
+		/* make sure fixed part of mesh header is there, also checks skb len */
+		if (!pskb_may_pull(rx->skb, hdr_len + 6))
+			goto drop_check;
+
+		mesh_hdr = (struct ieee80211s_hdr *)(skb->data + hdr_len);
+		ethertype_offset = hdr_len + ieee80211_get_mesh_hdrlen(mesh_hdr) +
+				   sizeof(rfc1042_header);
+
+		if (skb_copy_bits(rx->skb, ethertype_offset, &ethertype, 2) == 0 &&
+		    ethertype == rx->sdata->control_port_protocol)
+			return 0;
+	}
+
+drop_check:
 	/* Drop unencrypted frames if key is set. */
 	if (unlikely(!ieee80211_has_protected(fc) &&
 		     !ieee80211_is_any_nullfunc(fc) &&
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread