From 555cb715be8ef98b8ec362b23dfc254d432a35b1 Mon Sep 17 00:00:00 2001 From: Javier Cardona Date: Wed, 24 Oct 2012 12:43:30 -0700 Subject: mac80211: Only process mesh config header on frames that RA_MATCH Doing otherwise is wrong, and may wreak havoc on the mpp tables, specially if the frame is encrypted. Cc: stable@vger.kernel.org Reported-by: Chaoxing Lin Signed-off-by: Javier Cardona Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'net/mac80211/rx.c') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 61c621e9273f..1222127de9be 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1897,7 +1897,8 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx) mesh_rmc_check(hdr->addr3, mesh_hdr, rx->sdata)) return RX_DROP_MONITOR; - if (!ieee80211_is_data(hdr->frame_control)) + if (!ieee80211_is_data(hdr->frame_control) || + !(status->rx_flags & IEEE80211_RX_RA_MATCH)) return RX_CONTINUE; if (!mesh_hdr->ttl) @@ -1941,9 +1942,6 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx) } skb_set_queue_mapping(skb, q); - if (!(status->rx_flags & IEEE80211_RX_RA_MATCH)) - goto out; - if (!--mesh_hdr->ttl) { IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl); return RX_DROP_MONITOR; -- cgit v1.2.3-58-ga151 From 2ac64cd17f9af6d6adaa921bd9846a3c9bb9235c Mon Sep 17 00:00:00 2001 From: Javier Cardona Date: Wed, 24 Oct 2012 12:43:31 -0700 Subject: mac80211: Don't drop frames received with mesh ttl == 1 Prior this fix, those frames were not received, nor forwarded. Fix this to receive and not forward. Signed-off-by: Javier Cardona Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/mac80211/rx.c') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 1222127de9be..f73e0dda0d86 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1944,7 +1944,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx) if (!--mesh_hdr->ttl) { IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl); - return RX_DROP_MONITOR; + goto out; } if (!ifmsh->mshcfg.dot11MeshForwarding) -- cgit v1.2.3-58-ga151 From f7fbf70ee9db6da6033ae50d100e017ac1f26555 Mon Sep 17 00:00:00 2001 From: Javier Cardona Date: Thu, 25 Oct 2012 11:10:18 -0700 Subject: mac80211: don't inspect Sequence Control field on control frames Per IEEE Std. 802.11-2012, Sec 8.2.4.4.1, the sequence Control field is not present in control frames. We noticed this problem when processing Block Ack Requests. Cc: stable@vger.kernel.org Signed-off-by: Javier Cardona Signed-off-by: Javier Lopez Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/mac80211/rx.c') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index f73e0dda0d86..c6865f2f47f8 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1462,6 +1462,10 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx) hdr = (struct ieee80211_hdr *)rx->skb->data; fc = hdr->frame_control; + + if (ieee80211_is_ctl(fc)) + return RX_CONTINUE; + sc = le16_to_cpu(hdr->seq_ctrl); frag = sc & IEEE80211_SCTL_FRAG; -- cgit v1.2.3-58-ga151 From 4a4f1a5808c8bb0b72a4f6e5904c53fb8c9cd966 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 26 Oct 2012 00:33:36 +0200 Subject: mac80211: check management frame header length Due to pskb_may_pull() checking the skb length, all non-management frames are checked on input whether their 802.11 header is fully present. Also add that check for management frames and remove a check that is now duplicate. This prevents accessing skb data beyond the frame end. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'net/mac80211/rx.c') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index c6865f2f47f8..99cdee16e31b 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1470,7 +1470,6 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx) frag = sc & IEEE80211_SCTL_FRAG; if (likely((!ieee80211_has_morefrags(fc) && frag == 0) || - (rx->skb)->len < 24 || is_multicast_ether_addr(hdr->addr1))) { /* not fragmented */ goto out; @@ -2915,10 +2914,15 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw, if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc)) local->dot11ReceivedFragmentCount++; - if (ieee80211_is_mgmt(fc)) - err = skb_linearize(skb); - else + if (ieee80211_is_mgmt(fc)) { + /* drop frame if too short for header */ + if (skb->len < ieee80211_hdrlen(fc)) + err = -ENOBUFS; + else + err = skb_linearize(skb); + } else { err = !pskb_may_pull(skb, ieee80211_hdrlen(fc)); + } if (err) { dev_kfree_skb(skb); -- cgit v1.2.3-58-ga151 From 9b395bc3be1cebf0144a127c7e67d56dbdac0930 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 26 Oct 2012 00:36:40 +0200 Subject: mac80211: verify that skb data is present A number of places in the mesh code don't check that the frame data is present and in the skb header when trying to access. Add those checks and the necessary pskb_may_pull() calls. This prevents accessing data that doesn't actually exist. To do this, export ieee80211_get_mesh_hdrlen() to be able to use it in mac80211. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg --- include/net/cfg80211.h | 9 +++++++++ net/mac80211/rx.c | 32 +++++++++++++++++++++++++++++++- net/wireless/util.c | 3 ++- 3 files changed, 42 insertions(+), 2 deletions(-) (limited to 'net/mac80211/rx.c') diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index f8cd4cf3fad8..7d5b6000378b 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -2651,6 +2651,15 @@ unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb); */ unsigned int __attribute_const__ ieee80211_hdrlen(__le16 fc); +/** + * ieee80211_get_mesh_hdrlen - get mesh extension header length + * @meshhdr: the mesh extension header, only the flags field + * (first byte) will be accessed + * Returns the length of the extension header, which is always at + * least 6 bytes and at most 18 if address 5 and 6 are present. + */ +unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr); + /** * DOC: Data path helpers * diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 99cdee16e31b..265a032dec49 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -531,6 +531,11 @@ ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx) if (ieee80211_is_action(hdr->frame_control)) { u8 category; + + /* make sure category field is present */ + if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE) + return RX_DROP_MONITOR; + mgmt = (struct ieee80211_mgmt *)hdr; category = mgmt->u.action.category; if (category != WLAN_CATEGORY_MESH_ACTION && @@ -1892,6 +1897,20 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx) hdr = (struct ieee80211_hdr *) skb->data; hdrlen = ieee80211_hdrlen(hdr->frame_control); + + /* make sure fixed part of mesh header is there, also checks skb len */ + if (!pskb_may_pull(rx->skb, hdrlen + 6)) + return RX_DROP_MONITOR; + + mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen); + + /* make sure full mesh header is there, also checks skb len */ + if (!pskb_may_pull(rx->skb, + hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr))) + return RX_DROP_MONITOR; + + /* reload pointers */ + hdr = (struct ieee80211_hdr *) skb->data; mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen); /* frame is in RMC, don't forward */ @@ -1915,9 +1934,12 @@ 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 { + } else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) { + /* has_a4 already checked in ieee80211_rx_mesh_check */ mpp_addr = hdr->addr4; proxied_addr = mesh_hdr->eaddr2; + } else { + return RX_DROP_MONITOR; } rcu_read_lock(); @@ -2354,6 +2376,10 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx) } break; case WLAN_CATEGORY_SELF_PROTECTED: + if (len < (IEEE80211_MIN_ACTION_SIZE + + sizeof(mgmt->u.action.u.self_prot.action_code))) + break; + switch (mgmt->u.action.u.self_prot.action_code) { case WLAN_SP_MESH_PEERING_OPEN: case WLAN_SP_MESH_PEERING_CLOSE: @@ -2372,6 +2398,10 @@ ieee80211_rx_h_action(struct ieee80211_rx_data *rx) } break; case WLAN_CATEGORY_MESH_ACTION: + if (len < (IEEE80211_MIN_ACTION_SIZE + + sizeof(mgmt->u.action.u.mesh_action.action_code))) + break; + if (!ieee80211_vif_is_mesh(&sdata->vif)) break; if (mesh_action_is_path_sel(mgmt) && diff --git a/net/wireless/util.c b/net/wireless/util.c index 45a09de1ffe3..2762e8329986 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -309,7 +309,7 @@ unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb) } EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb); -static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) +unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) { int ae = meshhdr->flags & MESH_FLAGS_AE; /* 802.11-2012, 8.2.4.7.3 */ @@ -323,6 +323,7 @@ static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) return 18; } } +EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen); int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, enum nl80211_iftype iftype) -- cgit v1.2.3-58-ga151 From 6dbda2d00d466225f9db1dc695ff852443f28832 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 26 Oct 2012 00:41:23 +0200 Subject: mac80211: make sure data is accessible in EAPOL check The code to allow EAPOL frames even when the station isn't yet marked associated needs to check that the incoming frame is long enough and due to paged RX it also can't assume skb->data contains the right data, it must use skb_copy_bits(). Fix this to avoid using data that doesn't really exist. Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'net/mac80211/rx.c') diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 265a032dec49..00ade7feb2e3 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -888,14 +888,16 @@ ieee80211_rx_h_check(struct ieee80211_rx_data *rx) */ if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION && ieee80211_is_data_present(hdr->frame_control)) { - u16 ethertype; - u8 *payload; - - payload = rx->skb->data + - ieee80211_hdrlen(hdr->frame_control); - ethertype = (payload[6] << 8) | payload[7]; - if (cpu_to_be16(ethertype) == - rx->sdata->control_port_protocol) + unsigned int hdrlen; + __be16 ethertype; + + hdrlen = ieee80211_hdrlen(hdr->frame_control); + + if (rx->skb->len < hdrlen + 8) + return RX_DROP_MONITOR; + + skb_copy_bits(rx->skb, hdrlen + 6, ðertype, 2); + if (ethertype == rx->sdata->control_port_protocol) return RX_CONTINUE; } -- cgit v1.2.3-58-ga151