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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Fred Veldini <fred.veldini@gmail.com>,
	Bob Copeland <me@bobcopeland.com>,
	Johannes Berg <johannes.berg@intel.com>
Subject: [PATCH 3.14 08/53] mac80211: mesh: flush mesh paths unconditionally
Date: Mon, 25 Jul 2016 13:54:50 -0700	[thread overview]
Message-ID: <20160725203514.583861972@linuxfoundation.org> (raw)
In-Reply-To: <20160725203514.202312855@linuxfoundation.org>

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bob Copeland <me@bobcopeland.com>

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>

---
 net/mac80211/mesh.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -161,6 +161,10 @@ void mesh_sta_cleanup(struct sta_info *s
 		del_timer_sync(&sta->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);
 }



  parent reply	other threads:[~2016-07-25 20:55 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-25 20:54 [PATCH 3.14 00/53] 3.14.74-stable review Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 01/53] crypto: ux500 - memmove the right size Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 02/53] sit: correct IP protocol used in ipip6_err Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 03/53] ipmr/ip6mr: Initialize the last assert time of mfc entries Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 04/53] net: alx: Work around the DMA RX overflow issue Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 05/53] usb: quirks: Add no-lpm quirk for Acer C120 LED Projector Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 06/53] usb: musb: Stop bulk endpoint while queue is rotated Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 07/53] usb: musb: Ensure rx reinit occurs for shared_fifo endpoints Greg Kroah-Hartman
2016-07-25 20:54 ` Greg Kroah-Hartman [this message]
2016-07-25 20:54 ` [PATCH 3.14 09/53] mac80211_hwsim: Add missing check for HWSIM_ATTR_SIGNAL Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 10/53] IB/mlx4: Properly initialize GRH TClass and FlowLabel in AHs Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 11/53] powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 12/53] powerpc/pseries: Fix PCI config address for DDW Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 13/53] powerpc/tm: Always reclaim in start_thread() for exec() class syscalls Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 14/53] USB: EHCI: declare hostpc register as zero-length array Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 15/53] x86, build: copy ldlinux.c32 to image.iso Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 16/53] kprobes/x86: Clear TF bit in fault on single-stepping Greg Kroah-Hartman
2016-07-25 20:54 ` [PATCH 3.14 17/53] x86/amd_nb: Fix boot crash on non-AMD systems Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 18/53] make nfs_atomic_open() call d_drop() on all ->open_context() errors Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 19/53] NFS: Fix another OPEN_DOWNGRADE bug Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 20/53] ARM: 8578/1: mm: ensure pmd_present only checks the valid bit Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 21/53] mm: Export migrate_page_move_mapping and migrate_page_copy Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 22/53] UBIFS: Implement ->migratepage() Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 23/53] posix_acl: Add set_posix_acl Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 24/53] nfsd: check permissions when setting ACLs Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 25/53] signal: remove warning about using SI_TKILL in rt_[tg]sigqueueinfo Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 28/53] KEYS: potential uninitialized variable Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 29/53] kvm: Fix irq route entries exceeding KVM_MAX_IRQ_ROUTES Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 30/53] HID: elo: kill not flush the work Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 31/53] HID: hiddev: validate num_values for HIDIOCGUSAGES, HIDIOCSUSAGES commands Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 32/53] tracing: Handle NULL formats in hold_module_trace_bprintk_format() Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 33/53] base: make module_create_drivers_dir race-free Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 34/53] drm/radeon: fix asic initialization for virtualized environments Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 36/53] perf/x86: Honor the architectural performance monitoring version Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 37/53] perf/x86: Fix undefined shift on 32-bit kernels Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 38/53] iio: Fix error handling in iio_trigger_attach_poll_func Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 39/53] staging: iio: accel: fix error check Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 40/53] iio: accel: kxsd9: fix the usage of spi_w8r8() Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 41/53] iio:ad7266: Fix broken regulator error handling Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 42/53] iio:ad7266: Fix support for optional regulators Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 43/53] iio:ad7266: Fix probe deferral for vref Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 44/53] tty/vt/keyboard: fix OOB access in do_compute_shiftstate() Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 45/53] ALSA: dummy: Fix a use-after-free at closing Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 46/53] ALSA: au88x0: Fix calculation in vortex_wtdma_bufshift() Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 47/53] ALSA: ctl: Stop notification after disconnection Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 48/53] scsi: fix race between simultaneous decrements of ->host_failed Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 49/53] Fix reconnect to not defer smb3 session reconnect long after socket reconnect Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 50/53] xen/acpi: allow xen-acpi-processor driver to load on Xen 4.7 Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 51/53] tmpfs: dont undo fallocate past its last page Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 52/53] tmpfs: fix regression hang in fallocate undo Greg Kroah-Hartman
2016-07-25 20:55 ` [PATCH 3.14 53/53] s390/seccomp: fix error return for filtered system calls Greg Kroah-Hartman
2016-07-26  1:52 ` [PATCH 3.14 00/53] 3.14.74-stable review Shuah Khan
2016-07-26 13:50 ` Guenter Roeck

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