| Message ID | 20200617082637.22670-3-markus.theil@tu-ilmenau.de (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | Fixes for 802.1X in mesh mode | expand |
> + /* 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; > + > + /* 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 (!pskb_may_pull(rx->skb, ethertype_offset + sizeof(ethertype)) || > + !ether_addr_equal(hdr->addr1, rx->sdata->vif.addr)) might be nicer to check the address first, pskb_may_pull() is potentially more expensive, and you should be able to check the header address already before even the first pskb_may_pull() here since it's in the normal header. But I don't understand the second pskb_may_pull() anyway, because you use skb_copy_bits() below? > + skb_copy_bits(rx->skb, ethertype_offset, ðertype, 2); > + if (ethertype == rx->sdata->control_port_protocol) > + goto pass_frame; can return 0 here immediately and save the label. johannes
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 21854a61a2b7..60293a9fa3dc 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2396,6 +2396,7 @@ 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 = (struct ieee80211_hdr *)rx->skb->data; struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); @@ -2406,12 +2407,37 @@ 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; + + /* 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 (!pskb_may_pull(rx->skb, ethertype_offset + sizeof(ethertype)) || + !ether_addr_equal(hdr->addr1, rx->sdata->vif.addr)) + goto drop_check; + + skb_copy_bits(rx->skb, ethertype_offset, ðertype, 2); + if (ethertype == rx->sdata->control_port_protocol) + goto pass_frame; + } + +drop_check: /* Drop unencrypted frames if key is set. */ if (unlikely(!ieee80211_has_protected(fc) && !ieee80211_is_any_nullfunc(fc) && ieee80211_is_data(fc) && rx->key)) return -EACCES; +pass_frame: return 0; }
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. If a check for eapol frames fails, the previous drop check is executed (thanks to a kernel test bot, which found an issue in a previous patch version here). 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. Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de> --- net/mac80211/rx.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)