From 62397da50bb20a6b812c949ef465d7e69fe54bb6 Mon Sep 17 00:00:00 2001 From: Martin Willi Date: Fri, 13 May 2016 12:41:48 +0200 Subject: [PATCH 1/3] mac80211_hwsim: Add missing check for HWSIM_ATTR_SIGNAL A wmediumd that does not send this attribute causes a NULL pointer dereference, as the attribute is accessed even if it does not exist. The attribute was required but never checked ever since userspace frame forwarding has been introduced. The issue gets more problematic once we allow wmediumd registration from user namespaces. Cc: stable@vger.kernel.org Fixes: 7882513bacb1 ("mac80211_hwsim driver support userspace frame tx/rx") Signed-off-by: Martin Willi Signed-off-by: Johannes Berg --- drivers/net/wireless/mac80211_hwsim.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 9ed0ed1bf514..4dd5adcdd29b 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -2776,6 +2776,7 @@ static int hwsim_tx_info_frame_received_nl(struct sk_buff *skb_2, if (!info->attrs[HWSIM_ATTR_ADDR_TRANSMITTER] || !info->attrs[HWSIM_ATTR_FLAGS] || !info->attrs[HWSIM_ATTR_COOKIE] || + !info->attrs[HWSIM_ATTR_SIGNAL] || !info->attrs[HWSIM_ATTR_TX_INFO]) goto out; From fe7a7c57629e8dcbc0e297363a9b2366d67a6dc5 Mon Sep 17 00:00:00 2001 From: Bob Copeland Date: Sun, 15 May 2016 13:19:16 -0400 Subject: [PATCH 2/3] mac80211: mesh: flush mesh paths unconditionally Currently, the mesh paths associated with a nexthop station are cleaned up in the following code path: __sta_info_destroy_part1 synchronize_net() __sta_info_destroy_part2 -> cleanup_single_sta -> mesh_sta_cleanup -> mesh_plink_deactivate -> mesh_path_flush_by_nexthop However, there are a couple of problems here: 1) the paths aren't flushed at all if the MPM is running in userspace (e.g. when using wpa_supplicant or authsae) 2) there is no synchronize_rcu between removing the path and readers accessing the nexthop, which means the following race is possible: CPU0 CPU1 ~~~~ ~~~~ sta_info_destroy_part1() synchronize_net() rcu_read_lock() mesh_nexthop_resolve() mpath = mesh_path_lookup() [...] -> mesh_path_flush_by_nexthop() sta = rcu_dereference( mpath->next_hop) kfree(sta) access sta <-- CRASH Fix both of these by unconditionally flushing paths before destroying the sta, and by adding a synchronize_net() after path flush to ensure no active readers can still dereference the sta. Fixes this crash: [ 348.529295] BUG: unable to handle kernel paging request at 00020040 [ 348.530014] IP: [] ieee80211_mps_set_frame_flags+0x40/0xaa [mac80211] [ 348.530014] *pde = 00000000 [ 348.530014] Oops: 0000 [#1] PREEMPT [ 348.530014] Modules linked in: drbg ansi_cprng ctr ccm ppp_generic slhc ipt_MASQUERADE nf_nat_masquerade_ipv4 8021q ] [ 348.530014] CPU: 0 PID: 20597 Comm: wget Tainted: G O 4.6.0-rc5-wt=V1 #1 [ 348.530014] Hardware name: To Be Filled By O.E.M./To be filled by O.E.M., BIOS 080016 11/07/2014 [ 348.530014] task: f64fa280 ti: f4f9c000 task.ti: f4f9c000 [ 348.530014] EIP: 0060:[] EFLAGS: 00010246 CPU: 0 [ 348.530014] EIP is at ieee80211_mps_set_frame_flags+0x40/0xaa [mac80211] [ 348.530014] EAX: f4ce63e0 EBX: 00000088 ECX: f3788416 EDX: 00020008 [ 348.530014] ESI: 00000000 EDI: 00000088 EBP: f6409a4c ESP: f6409a40 [ 348.530014] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 [ 348.530014] CR0: 80050033 CR2: 00020040 CR3: 33190000 CR4: 00000690 [ 348.530014] Stack: [ 348.530014] 00000000 f4ce63e0 f5f9bd80 f6409a64 f9291d80 0000ce67 f5d51e00 f4ce63e0 [ 348.530014] f3788416 f6409a80 f9291dc1 f4ce8320 f4ce63e0 f5d51e00 f4ce63e0 f4ce8320 [ 348.530014] f6409a98 f9277f6f 00000000 00000000 0000007c 00000000 f6409b2c f9278dd1 [ 348.530014] Call Trace: [ 348.530014] [] mesh_nexthop_lookup+0xbb/0xc8 [mac80211] [ 348.530014] [] mesh_nexthop_resolve+0x34/0xd8 [mac80211] [ 348.530014] [] ieee80211_xmit+0x92/0xc1 [mac80211] [ 348.530014] [] __ieee80211_subif_start_xmit+0x807/0x83c [mac80211] [ 348.530014] [] ? sch_direct_xmit+0xd7/0x1b3 [ 348.530014] [] ? __local_bh_enable_ip+0x5d/0x7b [ 348.530014] [] ? nf_nat_ipv4_out+0x4c/0xd0 [nf_nat_ipv4] [ 348.530014] [] ? iptable_nat_ipv4_fn+0xf/0xf [iptable_nat] [ 348.530014] [] ? netif_skb_features+0x14d/0x30a [ 348.530014] [] ieee80211_subif_start_xmit+0xa/0xe [mac80211] [ 348.530014] [] dev_hard_start_xmit+0x1f8/0x267 [ 348.530014] [] ? validate_xmit_skb.isra.120.part.121+0x10/0x253 [ 348.530014] [] sch_direct_xmit+0x8b/0x1b3 [ 348.530014] [] __dev_queue_xmit+0x2c8/0x513 [ 348.530014] [] dev_queue_xmit+0xa/0xc [ 348.530014] [] batadv_send_skb_packet+0xd6/0xec [batman_adv] [ 348.530014] [] batadv_send_unicast_skb+0x15/0x4a [batman_adv] [ 348.530014] [] batadv_dat_send_data+0x27e/0x310 [batman_adv] [ 348.530014] [] ? batadv_tt_global_hash_find.isra.11+0x8/0xa [batman_adv] [ 348.530014] [] batadv_dat_snoop_outgoing_arp_request+0x208/0x23d [batman_adv] [ 348.530014] [] batadv_interface_tx+0x206/0x385 [batman_adv] [ 348.530014] [] dev_hard_start_xmit+0x1f8/0x267 [ 348.530014] [] ? validate_xmit_skb.isra.120.part.121+0x10/0x253 [ 348.530014] [] sch_direct_xmit+0x8b/0x1b3 [ 348.530014] [] __dev_queue_xmit+0x2c8/0x513 [ 348.530014] [] ? igb_xmit_frame+0x57/0x72 [igb] [ 348.530014] [] dev_queue_xmit+0xa/0xc [ 348.530014] [] br_dev_queue_push_xmit+0xeb/0xfb [bridge] [ 348.530014] [] br_forward_finish+0x29/0x74 [bridge] [ 348.530014] [] ? deliver_clone+0x3b/0x3b [bridge] [ 348.530014] [] __br_forward+0x89/0xe7 [bridge] [ 348.530014] [] ? br_dev_queue_push_xmit+0xfb/0xfb [bridge] [ 348.530014] [] deliver_clone+0x34/0x3b [bridge] [ 348.530014] [] ? br_flood+0x95/0x95 [bridge] [ 348.530014] [] br_flood+0x77/0x95 [bridge] [ 348.530014] [] br_flood_forward+0x13/0x1a [bridge] [ 348.530014] [] ? br_flood+0x95/0x95 [bridge] [ 348.530014] [] br_handle_frame_finish+0x392/0x3db [bridge] [ 348.530014] [] ? nf_iterate+0x2b/0x6b [ 348.530014] [] br_handle_frame+0x1e6/0x240 [bridge] [ 348.530014] [] ? br_handle_local_finish+0x6a/0x6a [bridge] [ 348.530014] [] __netif_receive_skb_core+0x43a/0x66b [ 348.530014] [] ? br_handle_frame_finish+0x3db/0x3db [bridge] [ 348.530014] [] ? resched_curr+0x19/0x37 [ 348.530014] [] ? check_preempt_wakeup+0xbf/0xfe [ 348.530014] [] ? ktime_get_with_offset+0x5c/0xfc [ 348.530014] [] __netif_receive_skb+0x47/0x55 [ 348.530014] [] netif_receive_skb_internal+0x40/0x5a [ 348.530014] [] napi_gro_receive+0x3a/0x94 [ 348.530014] [] igb_poll+0x6fd/0x9ad [igb] [ 348.530014] [] ? swake_up_locked+0x14/0x26 [ 348.530014] [] net_rx_action+0xde/0x250 [ 348.530014] [] __do_softirq+0x8a/0x163 [ 348.530014] [] ? __hrtimer_tasklet_trampoline+0x19/0x19 [ 348.530014] [] do_softirq_own_stack+0x26/0x2c [ 348.530014] [ 348.530014] [] irq_exit+0x31/0x6f [ 348.530014] [] do_IRQ+0x8d/0xa0 [ 348.530014] [] common_interrupt+0x2c/0x40 [ 348.530014] Code: e7 8c 00 66 81 ff 88 00 75 12 85 d2 75 0e b2 c3 b8 83 e9 29 f9 e8 a7 5f f9 c6 eb 74 66 81 e3 8c 005 [ 348.530014] EIP: [] ieee80211_mps_set_frame_flags+0x40/0xaa [mac80211] SS:ESP 0068:f6409a40 [ 348.530014] CR2: 0000000000020040 [ 348.530014] ---[ end trace 48556ac26779732e ]--- [ 348.530014] Kernel panic - not syncing: Fatal exception in interrupt [ 348.530014] Kernel Offset: disabled Cc: stable@vger.kernel.org Reported-by: Fred Veldini Tested-by: Fred Veldini Signed-off-by: Bob Copeland Signed-off-by: Johannes Berg --- net/mac80211/mesh.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c index 4c6404e1ad6e..21b1fdf5d01d 100644 --- a/net/mac80211/mesh.c +++ b/net/mac80211/mesh.c @@ -161,6 +161,10 @@ void mesh_sta_cleanup(struct sta_info *sta) del_timer_sync(&sta->mesh->plink_timer); } + /* make sure no readers can access nexthop sta from here on */ + mesh_path_flush_by_nexthop(sta); + synchronize_net(); + if (changed) ieee80211_mbss_info_change_notify(sdata, changed); } From 6fe04128f158c5ad27e7504bfdf1b12e63331bc9 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Thu, 19 May 2016 17:34:38 +0200 Subject: [PATCH 3/3] mac80211: fix fast_tx header alignment The header field is defined as u8[] but also accessed as struct ieee80211_hdr. Enforce an alignment of 2 to prevent unnecessary unaligned accesses, which can be very harmful for performance on many platforms. Fixes: e495c24731a2 ("mac80211: extend fast-xmit for more ciphers") Cc: stable@vger.kernel.org Signed-off-by: Felix Fietkau Signed-off-by: Johannes Berg --- net/mac80211/sta_info.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h index c8b8ccc370eb..78b0ef32dddd 100644 --- a/net/mac80211/sta_info.h +++ b/net/mac80211/sta_info.h @@ -280,7 +280,7 @@ struct ieee80211_fast_tx { u8 sa_offs, da_offs, pn_offs; u8 band; u8 hdr[30 + 2 + IEEE80211_FAST_XMIT_MAX_IV + - sizeof(rfc1042_header)]; + sizeof(rfc1042_header)] __aligned(2); struct rcu_head rcu_head; };