Bob Copeland 7b90e041d1 mac80211: mesh: flush mesh paths unconditionally ... commit fe7a7c57629e8dcbc0e297363a9b2366d67a6dc5 upstream. 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: [<f929245d>] 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:[<f929245d>] 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] [<f9291d80>] mesh_nexthop_lookup+0xbb/0xc8 [mac80211] [ 348.530014] [<f9291dc1>] mesh_nexthop_resolve+0x34/0xd8 [mac80211] [ 348.530014] [<f9277f6f>] ieee80211_xmit+0x92/0xc1 [mac80211] [ 348.530014] [<f9278dd1>] __ieee80211_subif_start_xmit+0x807/0x83c [mac80211] [ 348.530014] [<c04df012>] ? sch_direct_xmit+0xd7/0x1b3 [ 348.530014] [<c022a8c6>] ? __local_bh_enable_ip+0x5d/0x7b [ 348.530014] [<f956870c>] ? nf_nat_ipv4_out+0x4c/0xd0 [nf_nat_ipv4] [ 348.530014] [<f957e036>] ? iptable_nat_ipv4_fn+0xf/0xf [iptable_nat] [ 348.530014] [<c04c6f45>] ? netif_skb_features+0x14d/0x30a [ 348.530014] [<f9278e10>] ieee80211_subif_start_xmit+0xa/0xe [mac80211] [ 348.530014] [<c04c769c>] dev_hard_start_xmit+0x1f8/0x267 [ 348.530014] [<c04c7261>] ? validate_xmit_skb.isra.120.part.121+0x10/0x253 [ 348.530014] [<c04defc6>] sch_direct_xmit+0x8b/0x1b3 [ 348.530014] [<c04c7a9c>] __dev_queue_xmit+0x2c8/0x513 [ 348.530014] [<c04c7cfb>] dev_queue_xmit+0xa/0xc [ 348.530014] [<f91bfc7a>] batadv_send_skb_packet+0xd6/0xec [batman_adv] [ 348.530014] [<f91bfdc4>] batadv_send_unicast_skb+0x15/0x4a [batman_adv] [ 348.530014] [<f91b5938>] batadv_dat_send_data+0x27e/0x310 [batman_adv] [ 348.530014] [<f91c30b5>] ? batadv_tt_global_hash_find.isra.11+0x8/0xa [batman_adv] [ 348.530014] [<f91b63f3>] batadv_dat_snoop_outgoing_arp_request+0x208/0x23d [batman_adv] [ 348.530014] [<f91c0cd9>] batadv_interface_tx+0x206/0x385 [batman_adv] [ 348.530014] [<c04c769c>] dev_hard_start_xmit+0x1f8/0x267 [ 348.530014] [<c04c7261>] ? validate_xmit_skb.isra.120.part.121+0x10/0x253 [ 348.530014] [<c04defc6>] sch_direct_xmit+0x8b/0x1b3 [ 348.530014] [<c04c7a9c>] __dev_queue_xmit+0x2c8/0x513 [ 348.530014] [<f80cbd2a>] ? igb_xmit_frame+0x57/0x72 [igb] [ 348.530014] [<c04c7cfb>] dev_queue_xmit+0xa/0xc [ 348.530014] [<f843a326>] br_dev_queue_push_xmit+0xeb/0xfb [bridge] [ 348.530014] [<f843a35f>] br_forward_finish+0x29/0x74 [bridge] [ 348.530014] [<f843a23b>] ? deliver_clone+0x3b/0x3b [bridge] [ 348.530014] [<f843a714>] __br_forward+0x89/0xe7 [bridge] [ 348.530014] [<f843a336>] ? br_dev_queue_push_xmit+0xfb/0xfb [bridge] [ 348.530014] [<f843a234>] deliver_clone+0x34/0x3b [bridge] [ 348.530014] [<f843a68b>] ? br_flood+0x95/0x95 [bridge] [ 348.530014] [<f843a66d>] br_flood+0x77/0x95 [bridge] [ 348.530014] [<f843a809>] br_flood_forward+0x13/0x1a [bridge] [ 348.530014] [<f843a68b>] ? br_flood+0x95/0x95 [bridge] [ 348.530014] [<f843b877>] br_handle_frame_finish+0x392/0x3db [bridge] [ 348.530014] [<c04e9b2b>] ? nf_iterate+0x2b/0x6b [ 348.530014] [<f843baa6>] br_handle_frame+0x1e6/0x240 [bridge] [ 348.530014] [<f843b4e5>] ? br_handle_local_finish+0x6a/0x6a [bridge] [ 348.530014] [<c04c4ba0>] __netif_receive_skb_core+0x43a/0x66b [ 348.530014] [<f843b8c0>] ? br_handle_frame_finish+0x3db/0x3db [bridge] [ 348.530014] [<c023cea4>] ? resched_curr+0x19/0x37 [ 348.530014] [<c0240707>] ? check_preempt_wakeup+0xbf/0xfe [ 348.530014] [<c0255dec>] ? ktime_get_with_offset+0x5c/0xfc [ 348.530014] [<c04c4fc1>] __netif_receive_skb+0x47/0x55 [ 348.530014] [<c04c57ba>] netif_receive_skb_internal+0x40/0x5a [ 348.530014] [<c04c61ef>] napi_gro_receive+0x3a/0x94 [ 348.530014] [<f80ce8d5>] igb_poll+0x6fd/0x9ad [igb] [ 348.530014] [<c0242bd8>] ? swake_up_locked+0x14/0x26 [ 348.530014] [<c04c5d29>] net_rx_action+0xde/0x250 [ 348.530014] [<c022a743>] __do_softirq+0x8a/0x163 [ 348.530014] [<c022a6b9>] ? __hrtimer_tasklet_trampoline+0x19/0x19 [ 348.530014] [<c021100f>] do_softirq_own_stack+0x26/0x2c [ 348.530014] <IRQ> [ 348.530014] [<c022a957>] irq_exit+0x31/0x6f [ 348.530014] [<c0210eb2>] do_IRQ+0x8d/0xa0 [ 348.530014] [<c058152c>] 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: [<f929245d>] 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 Reported-by: Fred Veldini <fred.veldini@gmail.com> Tested-by: Fred Veldini <fred.veldini@gmail.com> Signed-off-by: Bob Copeland <me@bobcopeland.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2016-07-27 09:47:27 -07:00
..
6lowpan	6lowpan: put mcast compression in an own function	2015-10-21 00:49:25 +02:00
9p	IB/cma: Add support for network namespaces	2015-10-28 12:32:48 -04:00
802
8021q	vlan: Do not put vlan headers back on bridge and macvlan ports	2015-11-17 14:38:35 -05:00
appletalk
atm	atm: deal with setting entry before mkip was called	2015-09-17 22:13:32 -07:00
ax25	AX.25: Close socket connection on session completion	2016-07-11 09:31:12 -07:00
batman-adv	batman-adv: Reduce refcnt of removed router when updating route	2016-05-11 11:21:18 +02:00
bluetooth	Bluetooth: Fix potential buffer overflow with Add Advertising	2016-04-12 09:08:54 -07:00
bridge	Bridge: Fix ipv6 mc snooping if bridge has no ipv6 address	2016-07-11 09:31:11 -07:00
caif	net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA	2015-12-01 15:45:05 -05:00
can	can: avoid using timeval for uapi	2015-10-13 17:42:34 +02:00
ceph	libceph: don't spam dmesg with stray reply warnings	2016-03-03 15:07:26 -08:00
core	bpf: try harder on clones when writing into skb	2016-07-11 09:31:12 -07:00
dcb	net/dcb: make dcbnl.c explicitly non-modular	2015-10-09 07:52:27 -07:00
dccp	tcp/dccp: remove obsolete WARN_ON() in icmp handlers	2016-04-20 15:42:04 +09:00
decnet	decnet: Do not build routes to devices without decnet private data.	2016-05-18 17:06:35 -07:00
dns_resolver	net: dns_resolver: convert time_t to time64_t	2015-11-18 16:27:46 -05:00
dsa	net: dsa: use switchdev obj for VLAN add/del ops	2015-11-01 15:56:11 -05:00
ethernet	net: help compiler generate better code in eth_get_headlen	2015-09-28 22:51:15 -07:00
hsr	net/hsr: fix a warning message	2015-11-23 14:56:15 -05:00
ieee802154	net: fix percpu memory leaks	2015-11-02 22:47:14 -05:00
ipv4	ipmr/ip6mr: Initialize the last assert time of mfc entries.	2016-07-11 09:31:11 -07:00
ipv6	ipmr/ip6mr: Initialize the last assert time of mfc entries.	2016-07-11 09:31:11 -07:00
ipx
irda	net: add validation for the socket syscall protocol argument	2015-12-14 16:09:30 -05:00
iucv	af_iucv: Validate socket address length in iucv_sock_bind()	2016-03-03 15:07:03 -08:00
key	af_key: fix two typos	2015-10-23 03:05:19 -07:00
l2tp	l2tp: fix configuration passed to setup_udp_tunnel_sock()	2016-06-24 10:18:17 -07:00
l3mdev	net: Add netif_is_l3_slave	2015-10-07 04:27:43 -07:00
lapb
llc	net: fix infoleak in llc	2016-05-18 17:06:40 -07:00
mac80211	mac80211: mesh: flush mesh paths unconditionally	2016-07-27 09:47:27 -07:00
mac802154	mac802154: llsec: use kzfree	2015-10-21 00:49:24 +02:00
mpls	mpls: find_outdev: check for err ptr in addition to NULL check	2016-04-20 15:42:07 +09:00
netfilter	netfilter: x_tables: introduce and use xt_copy_counters_from_user	2016-06-24 10:18:24 -07:00
netlabel
netlink	netlink: Fix dump skb leak/double free	2016-06-24 10:18:16 -07:00
netrom	netfilter: Remove spurios included of netfilter.h	2015-06-18 21:14:32 +02:00
nfc	net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA	2015-12-01 15:45:05 -05:00
openvswitch	vxlan, gre, geneve: Set a large MTU on ovs-created tunnel devices	2016-06-24 10:18:18 -07:00
packet	packet: fix heap info leak in PACKET_DIAG_MCLIST sock_diag interface	2016-05-18 17:06:35 -07:00
phonet	phonet: properly unshare skbs in phonet_rcv()	2016-01-31 11:29:00 -08:00
rds	RDS: fix race condition when sending a message on unbound socket	2015-11-24 17:20:09 -05:00
rfkill	rfkill: fix rfkill_fop_read wait_event usage	2016-03-03 15:07:26 -08:00
rose	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2015-06-24 02:58:51 -07:00
rxrpc	net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA	2015-12-01 15:45:05 -05:00
sched	bpf: try harder on clones when writing into skb	2016-07-11 09:31:12 -07:00
sctp	sctp: lack the check for ports in sctp_v6_cmp_addr	2016-04-20 15:41:58 +09:00
sunrpc	sunrpc: fix stripping of padded MIC tokens	2016-06-07 18:14:36 -07:00
switchdev	switchdev: pass pointer to fib_info instead of copy	2016-06-24 10:18:16 -07:00
tipc	tipc: fix nametable publication field in nl compat	2016-06-24 10:18:16 -07:00
unix	unix_diag: fix incorrect sign extension in unix_lookup_by_ino	2016-03-03 15:07:07 -08:00
vmw_vsock	VSOCK: do not disconnect socket when peer has shutdown SEND only	2016-05-18 17:06:41 -07:00
wimax	net:wimax: Fix doucble word "the the" in networking.xml	2015-08-09 22:43:52 -07:00
wireless	wext: Fix 32 bit iwpriv compatibility issue with 64 bit Kernel	2016-06-24 10:18:20 -07:00
x25	net: fix a kernel infoleak in x25 module	2016-05-18 17:06:43 -07:00
xfrm	xfrm: Fix crash observed during device unregistration and decryption	2016-04-20 15:42:05 +09:00
compat.c
Kconfig	net: Introduce L3 Master device abstraction	2015-09-29 20:40:32 -07:00
Makefile	net: Introduce L3 Master device abstraction	2015-09-29 20:40:32 -07:00
socket.c	net: Fix use after free in the recvmmsg exit path	2016-04-20 15:42:03 +09:00
sysctl_net.c	net: sysctl: fix a kmemleak warning	2015-10-23 06:22:08 -07:00