[PATCH AUTOSEL 5.4 05/18] mac80211: allow rx of mesh eapol frames with default rx key
From: Sasha Levin <sashal@kernel.org>
Date: 2020-07-14 14:44:10
Also in:
lkml, netdev, stable
Subsystem:
mac80211, the rest · Maintainers:
Johannes Berg, Linus Torvalds
From: Markus Theil <redacted> [ 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 <redacted> Link: https://lore.kernel.org/r/20200625104214.50319-1-markus.theil@tu-ilmenau.de (local) [small code cleanups] Signed-off-by: Johannes Berg <redacted> 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, ðertype, 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