Commit 2204ce84 authored by Rajkumar Manoharan's avatar Rajkumar Manoharan Committed by Ben Hutchings

mac80211: strictly check mesh address extension mode

commit 5667c86a upstream.

Mesh forwarding path checks for address extension mode to fetch
appropriate proxied address and MPP address. Existing condition
that looks for 6 address format is not strict enough so that
frames with improper values are processed and invalid entries
are added into MPP table. Fix that by adding a stricter check before
processing the packet.

Per IEEE Std 802.11s-2011 spec. Table 7-6g1 lists address extension
mode 0x3 as reserved one. And also Table Table 9-13 does not specify
0x3 as valid address field.

Fixes: 9b395bc3 ("mac80211: verify that skb data is present")
Signed-off-by: default avatarRajkumar Manoharan <rmanohar@qti.qualcomm.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
[bwh: Backported to 3.16: add mesh_flags variable in ieee80211_data_to_8023(),
 added separately upstream]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent f6021896
......@@ -2108,7 +2108,8 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
if (is_multicast_ether_addr(hdr->addr1)) {
mpp_addr = hdr->addr3;
proxied_addr = mesh_hdr->eaddr1;
} else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) {
} else if ((mesh_hdr->flags & MESH_FLAGS_AE) ==
MESH_FLAGS_AE_A5_A6) {
/* has_a4 already checked in ieee80211_rx_mesh_check */
mpp_addr = hdr->addr4;
proxied_addr = mesh_hdr->eaddr2;
......
......@@ -401,12 +401,15 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
if (iftype == NL80211_IFTYPE_MESH_POINT) {
struct ieee80211s_hdr *meshdr =
(struct ieee80211s_hdr *) (skb->data + hdrlen);
u8 mesh_flags;
/* make sure meshdr->flags is on the linear part */
if (!pskb_may_pull(skb, hdrlen + 1))
return -1;
if (meshdr->flags & MESH_FLAGS_AE_A4)
mesh_flags = meshdr->flags & MESH_FLAGS_AE;
if (mesh_flags == MESH_FLAGS_AE_A4)
return -1;
if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
if (mesh_flags == MESH_FLAGS_AE_A5_A6) {
skb_copy_bits(skb, hdrlen +
offsetof(struct ieee80211s_hdr, eaddr1),
dst, ETH_ALEN);
......@@ -427,12 +430,15 @@ int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
if (iftype == NL80211_IFTYPE_MESH_POINT) {
struct ieee80211s_hdr *meshdr =
(struct ieee80211s_hdr *) (skb->data + hdrlen);
u8 mesh_flags;
/* make sure meshdr->flags is on the linear part */
if (!pskb_may_pull(skb, hdrlen + 1))
return -1;
if (meshdr->flags & MESH_FLAGS_AE_A5_A6)
mesh_flags = meshdr->flags & MESH_FLAGS_AE;
if (mesh_flags == MESH_FLAGS_AE_A5_A6)
return -1;
if (meshdr->flags & MESH_FLAGS_AE_A4)
if (mesh_flags == MESH_FLAGS_AE_A4)
skb_copy_bits(skb, hdrlen +
offsetof(struct ieee80211s_hdr, eaddr1),
src, ETH_ALEN);
......
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