This is a note to let you know that I've just added the patch titled mac80211: strictly check mesh address extension mode to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mac80211-strictly-check-mesh-address-extension-mode.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5667c86acf021e6dcf02584408b4484a273ac68f Mon Sep 17 00:00:00 2001 From: Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxxxx> Date: Sun, 14 May 2017 21:41:55 -0700 Subject: mac80211: strictly check mesh address extension mode From: Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxxxx> commit 5667c86acf021e6dcf02584408b4484a273ac68f 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: 9b395bc3be1c ("mac80211: verify that skb data is present") Signed-off-by: Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/mac80211/rx.c | 3 ++- net/wireless/util.c | 10 ++++++---- 2 files changed, 8 insertions(+), 5 deletions(-) --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2471,7 +2471,8 @@ ieee80211_rx_h_mesh_fwding(struct ieee80 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; --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -454,6 +454,8 @@ int ieee80211_data_to_8023_exthdr(struct if (iftype == NL80211_IFTYPE_MESH_POINT) skb_copy_bits(skb, hdrlen, &mesh_flags, 1); + mesh_flags &= MESH_FLAGS_AE; + switch (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) { case cpu_to_le16(IEEE80211_FCTL_TODS): @@ -469,9 +471,9 @@ int ieee80211_data_to_8023_exthdr(struct iftype != NL80211_IFTYPE_STATION)) return -1; if (iftype == NL80211_IFTYPE_MESH_POINT) { - if (mesh_flags & MESH_FLAGS_AE_A4) + if (mesh_flags == MESH_FLAGS_AE_A4) return -1; - if (mesh_flags & MESH_FLAGS_AE_A5_A6) { + if (mesh_flags == MESH_FLAGS_AE_A5_A6) { skb_copy_bits(skb, hdrlen + offsetof(struct ieee80211s_hdr, eaddr1), tmp.h_dest, 2 * ETH_ALEN); @@ -487,9 +489,9 @@ int ieee80211_data_to_8023_exthdr(struct ether_addr_equal(tmp.h_source, addr))) return -1; if (iftype == NL80211_IFTYPE_MESH_POINT) { - if (mesh_flags & MESH_FLAGS_AE_A5_A6) + if (mesh_flags == MESH_FLAGS_AE_A5_A6) return -1; - if (mesh_flags & MESH_FLAGS_AE_A4) + if (mesh_flags == MESH_FLAGS_AE_A4) skb_copy_bits(skb, hdrlen + offsetof(struct ieee80211s_hdr, eaddr1), tmp.h_source, ETH_ALEN); Patches currently in stable-queue which might be from rmanohar@xxxxxxxxxxxxxxxx are queue-4.9/mac80211-strictly-check-mesh-address-extension-mode.patch