linux/net
Mirsad Goran Todorovac ef6e1997da wifi: mac80211: fortify the spinlock against deadlock by interrupt
In the function ieee80211_tx_dequeue() there is a particular locking
sequence:

begin:
	spin_lock(&local->queue_stop_reason_lock);
	q_stopped = local->queue_stop_reasons[q];
	spin_unlock(&local->queue_stop_reason_lock);

However small the chance (increased by ftracetest), an asynchronous
interrupt can occur in between of spin_lock() and spin_unlock(),
and the interrupt routine will attempt to lock the same
&local->queue_stop_reason_lock again.

This will cause a costly reset of the CPU and the wifi device or an
altogether hang in the single CPU and single core scenario.

The only remaining spin_lock(&local->queue_stop_reason_lock) that
did not disable interrupts was patched, which should prevent any
deadlocks on the same CPU/core and the same wifi device.

This is the probable trace of the deadlock:

kernel: ================================
kernel: WARNING: inconsistent lock state
kernel: 6.3.0-rc6-mt-20230401-00001-gf86822a1170f #4 Tainted: G        W
kernel: --------------------------------
kernel: inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
kernel: kworker/5:0/25656 [HC0[0]:SC0[0]:HE1:SE1] takes:
kernel: ffff9d6190779478 (&local->queue_stop_reason_lock){+.?.}-{2:2}, at: return_to_handler+0x0/0x40
kernel: {IN-SOFTIRQ-W} state was registered at:
kernel:   lock_acquire+0xc7/0x2d0
kernel:   _raw_spin_lock+0x36/0x50
kernel:   ieee80211_tx_dequeue+0xb4/0x1330 [mac80211]
kernel:   iwl_mvm_mac_itxq_xmit+0xae/0x210 [iwlmvm]
kernel:   iwl_mvm_mac_wake_tx_queue+0x2d/0xd0 [iwlmvm]
kernel:   ieee80211_queue_skb+0x450/0x730 [mac80211]
kernel:   __ieee80211_xmit_fast.constprop.66+0x834/0xa50 [mac80211]
kernel:   __ieee80211_subif_start_xmit+0x217/0x530 [mac80211]
kernel:   ieee80211_subif_start_xmit+0x60/0x580 [mac80211]
kernel:   dev_hard_start_xmit+0xb5/0x260
kernel:   __dev_queue_xmit+0xdbe/0x1200
kernel:   neigh_resolve_output+0x166/0x260
kernel:   ip_finish_output2+0x216/0xb80
kernel:   __ip_finish_output+0x2a4/0x4d0
kernel:   ip_finish_output+0x2d/0xd0
kernel:   ip_output+0x82/0x2b0
kernel:   ip_local_out+0xec/0x110
kernel:   igmpv3_sendpack+0x5c/0x90
kernel:   igmp_ifc_timer_expire+0x26e/0x4e0
kernel:   call_timer_fn+0xa5/0x230
kernel:   run_timer_softirq+0x27f/0x550
kernel:   __do_softirq+0xb4/0x3a4
kernel:   irq_exit_rcu+0x9b/0xc0
kernel:   sysvec_apic_timer_interrupt+0x80/0xa0
kernel:   asm_sysvec_apic_timer_interrupt+0x1f/0x30
kernel:   _raw_spin_unlock_irqrestore+0x3f/0x70
kernel:   free_to_partial_list+0x3d6/0x590
kernel:   __slab_free+0x1b7/0x310
kernel:   kmem_cache_free+0x52d/0x550
kernel:   putname+0x5d/0x70
kernel:   do_sys_openat2+0x1d7/0x310
kernel:   do_sys_open+0x51/0x80
kernel:   __x64_sys_openat+0x24/0x30
kernel:   do_syscall_64+0x5c/0x90
kernel:   entry_SYSCALL_64_after_hwframe+0x72/0xdc
kernel: irq event stamp: 5120729
kernel: hardirqs last  enabled at (5120729): [<ffffffff9d149936>] trace_graph_return+0xd6/0x120
kernel: hardirqs last disabled at (5120728): [<ffffffff9d149950>] trace_graph_return+0xf0/0x120
kernel: softirqs last  enabled at (5069900): [<ffffffff9cf65b60>] return_to_handler+0x0/0x40
kernel: softirqs last disabled at (5067555): [<ffffffff9cf65b60>] return_to_handler+0x0/0x40
kernel:
        other info that might help us debug this:
kernel:  Possible unsafe locking scenario:
kernel:        CPU0
kernel:        ----
kernel:   lock(&local->queue_stop_reason_lock);
kernel:   <Interrupt>
kernel:     lock(&local->queue_stop_reason_lock);
kernel:
         *** DEADLOCK ***
kernel: 8 locks held by kworker/5:0/25656:
kernel:  #0: ffff9d618009d138 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work+0x1ca/0x530
kernel:  #1: ffffb1ef4637fe68 ((work_completion)(&local->restart_work)){+.+.}-{0:0}, at: process_one_work+0x1ce/0x530
kernel:  #2: ffffffff9f166548 (rtnl_mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40
kernel:  #3: ffff9d6190778728 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: return_to_handler+0x0/0x40
kernel:  #4: ffff9d619077b480 (&mvm->mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40
kernel:  #5: ffff9d61907bacd8 (&trans_pcie->mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40
kernel:  #6: ffffffff9ef9cda0 (rcu_read_lock){....}-{1:2}, at: iwl_mvm_queue_state_change+0x59/0x3a0 [iwlmvm]
kernel:  #7: ffffffff9ef9cda0 (rcu_read_lock){....}-{1:2}, at: iwl_mvm_mac_itxq_xmit+0x42/0x210 [iwlmvm]
kernel:
        stack backtrace:
kernel: CPU: 5 PID: 25656 Comm: kworker/5:0 Tainted: G        W          6.3.0-rc6-mt-20230401-00001-gf86822a1170f #4
kernel: Hardware name: LENOVO 82H8/LNVNB161216, BIOS GGCN51WW 11/16/2022
kernel: Workqueue: events_freezable ieee80211_restart_work [mac80211]
kernel: Call Trace:
kernel:  <TASK>
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  dump_stack_lvl+0x5f/0xa0
kernel:  dump_stack+0x14/0x20
kernel:  print_usage_bug.part.46+0x208/0x2a0
kernel:  mark_lock.part.47+0x605/0x630
kernel:  ? sched_clock+0xd/0x20
kernel:  ? trace_clock_local+0x14/0x30
kernel:  ? __rb_reserve_next+0x5f/0x490
kernel:  ? _raw_spin_lock+0x1b/0x50
kernel:  __lock_acquire+0x464/0x1990
kernel:  ? mark_held_locks+0x4e/0x80
kernel:  lock_acquire+0xc7/0x2d0
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  ? ftrace_return_to_handler+0x8b/0x100
kernel:  ? preempt_count_add+0x4/0x70
kernel:  _raw_spin_lock+0x36/0x50
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  ieee80211_tx_dequeue+0xb4/0x1330 [mac80211]
kernel:  ? prepare_ftrace_return+0xc5/0x190
kernel:  ? ftrace_graph_func+0x16/0x20
kernel:  ? 0xffffffffc02ab0b1
kernel:  ? lock_acquire+0xc7/0x2d0
kernel:  ? iwl_mvm_mac_itxq_xmit+0x42/0x210 [iwlmvm]
kernel:  ? ieee80211_tx_dequeue+0x9/0x1330 [mac80211]
kernel:  ? __rcu_read_lock+0x4/0x40
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_mvm_mac_itxq_xmit+0xae/0x210 [iwlmvm]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_mvm_queue_state_change+0x311/0x3a0 [iwlmvm]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_mvm_wake_sw_queue+0x17/0x20 [iwlmvm]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_txq_gen2_unmap+0x1c9/0x1f0 [iwlwifi]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_txq_gen2_free+0x55/0x130 [iwlwifi]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_txq_gen2_tx_free+0x63/0x80 [iwlwifi]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  _iwl_trans_pcie_gen2_stop_device+0x3f3/0x5b0 [iwlwifi]
kernel:  ? _iwl_trans_pcie_gen2_stop_device+0x9/0x5b0 [iwlwifi]
kernel:  ? mutex_lock_nested+0x4/0x30
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_trans_pcie_gen2_stop_device+0x5f/0x90 [iwlwifi]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_mvm_stop_device+0x78/0xd0 [iwlmvm]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  __iwl_mvm_mac_start+0x114/0x210 [iwlmvm]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  iwl_mvm_mac_start+0x76/0x150 [iwlmvm]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  drv_start+0x79/0x180 [mac80211]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  ieee80211_reconfig+0x1523/0x1ce0 [mac80211]
kernel:  ? synchronize_net+0x4/0x50
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  ieee80211_restart_work+0x108/0x170 [mac80211]
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  process_one_work+0x250/0x530
kernel:  ? ftrace_regs_caller_end+0x66/0x66
kernel:  worker_thread+0x48/0x3a0
kernel:  ? __pfx_worker_thread+0x10/0x10
kernel:  kthread+0x10f/0x140
kernel:  ? __pfx_kthread+0x10/0x10
kernel:  ret_from_fork+0x29/0x50
kernel:  </TASK>

Fixes: 4444bc2116 ("wifi: mac80211: Proper mark iTXQs for resumption")
Link: https://lore.kernel.org/all/1f58a0d1-d2b9-d851-73c3-93fcc607501c@alu.unizg.hr/
Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Gregory Greenman <gregory.greenman@intel.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/all/cdc80531-f25f-6f9d-b15f-25e16130b53a@alu.unizg.hr/
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Alexander Wetzel <alexander@wetzel-home.de>
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: tag, or it goes automatically?
Link: https://lore.kernel.org/r/20230425164005.25272-1-mirsad.todorovac@alu.unizg.hr
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-16 10:11:38 -07:00
..
6lowpan 6lowpan: Remove redundant initialisation. 2023-03-29 08:22:52 +01:00
9p Including fixes from netfilter. 2023-05-05 19:12:01 -07:00
802 treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
8021q vlan: Add MACsec offload operations for VLAN interface 2023-04-21 08:22:14 +01:00
appletalk
atm Networking changes for 6.4. 2023-04-26 16:07:23 -07:00
ax25
batman-adv net: vlan: introduce skb_vlan_eth_hdr() 2023-04-23 14:16:44 +01:00
bluetooth Driver core changes for 6.4-rc1 2023-04-27 11:53:57 -07:00
bpf bpf: add test_run support for netfilter program type 2023-04-21 11:34:50 -07:00
bpfilter
bridge bridge: Allow setting per-{Port, VLAN} neighbor suppression state 2023-04-21 08:25:50 +01:00
caif net: caif: Fix use-after-free in cfusbl_device_notify() 2023-03-02 22:22:07 -08:00
can Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-04-06 12:01:20 -07:00
ceph Networking changes for 6.3. 2023-02-21 18:24:12 -08:00
core tcp: fix skb_copy_ubufs() vs BIG TCP 2023-04-28 09:40:38 +01:00
dcb net: dcb: add helper functions to retrieve PCP and DSCP rewrite maps 2023-01-20 09:33:22 +00:00
dccp netfilter: keep conntrack reference until IPsecv6 policy checks are done 2023-03-22 21:50:23 +01:00
devlink devlink: drop leftover duplicate/unused code 2023-02-20 11:38:35 +00:00
dns_resolver
dsa net: dsa: tag_ocelot: call only the relevant portion of __skb_vlan_pop() on TX 2023-04-23 14:16:45 +01:00
ethernet
ethtool ethtool: Fix uninitialized number of lanes 2023-05-03 09:13:20 +01:00
handshake net/handshake: Fix section mismatch in handshake_exit 2023-04-21 20:24:57 -07:00
hsr hsr: ratelimit only when errors are printed 2023-03-16 21:11:03 -07:00
ieee802154 net: ieee802154: remove an unnecessary null pointer check 2023-03-17 09:13:53 +01:00
ife
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-04-26 10:17:46 +02:00
ipv6 net: ipv6: fix skb hash for some RST packets 2023-04-28 09:53:43 +01:00
iucv net/iucv: Fix size of interrupt data 2023-03-16 17:34:40 -07:00
kcm net/sock: Introduce trace_sk_data_ready() 2023-01-23 11:26:50 +00:00
key af_key: Fix heap information leak 2023-02-13 09:30:14 +00:00
l2tp l2tp: generate correct module alias strings 2023-03-31 09:25:12 +01:00
l3mdev
lapb
llc
mac80211 wifi: mac80211: fortify the spinlock against deadlock by interrupt 2023-05-16 10:11:38 -07:00
mac802154 mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep() 2023-04-05 13:48:04 +00:00
mctp mctp: remove MODULE_LICENSE in non-modules 2023-03-09 23:06:21 -08:00
mpls net: mpls: fix stale pointer if allocation fails during device rename 2023-02-15 10:26:37 +00:00
mptcp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-04-20 16:29:51 -07:00
ncsi net/ncsi: clear Tx enable mode when handling a Config required AEN 2023-04-28 09:35:33 +01:00
netfilter Including fixes from netfilter. 2023-05-05 19:12:01 -07:00
netlabel
netlink Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-04-26 10:17:46 +02:00
netrom netrom: Fix use-after-free caused by accept on already connected socket 2023-01-30 07:30:47 +00:00
nfc nfc: change order inside nfc_se_io error path 2023-03-07 13:37:05 -08:00
nsh
openvswitch net: openvswitch: fix race on port output 2023-04-07 19:42:53 -07:00
packet af_packet: Don't send zero-byte data in packet_sendmsg_spkt(). 2023-05-03 09:20:18 +01:00
phonet net/sock: Introduce trace_sk_data_ready() 2023-01-23 11:26:50 +00:00
psample
qrtr net: qrtr: Fix an uninit variable access bug in qrtr_tx_resume() 2023-04-13 09:35:30 +02:00
rds rds: rds_rm_zerocopy_callback() correct order for list_add_tail() 2023-02-13 09:33:39 +00:00
rfkill net: rfkill-gpio: Add explicit include for of.h 2023-04-06 20:36:27 +02:00
rose net/rose: Fix to not accept on connected socket 2023-01-28 00:19:57 -08:00
rxrpc Including fixes from netfilter. 2023-05-05 19:12:01 -07:00
sched net/sched: flower: fix error handler on replace 2023-05-05 10:01:31 +01:00
sctp sctp: delete the nested flexible array hmac 2023-04-21 08:19:30 +01:00
smc - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
strparser
sunrpc NFSD 6.4 Release Notes 2023-04-29 11:04:14 -07:00
switchdev
tipc Networking changes for 6.3. 2023-02-21 18:24:12 -08:00
tls net: tls: fix device-offloaded sendpage straddling records 2023-03-06 13:26:16 -08:00
unix af_unix: annotate lockless accesses to sk->sk_err 2023-03-17 08:25:05 +00:00
vmw_vsock vsock/loopback: don't disable irqs for queue access 2023-04-14 11:04:04 +01:00
wireless wifi: cfg80211: Drop entries with invalid BSSIDs in RNR 2023-05-16 10:09:50 -07:00
x25 net/x25: Fix to not accept on connected socket 2023-01-25 09:51:04 +00:00
xdp bpf-next-for-netdev 2023-04-13 16:43:38 -07:00
xfrm ipsec-next-2023-04-19 2023-04-19 18:46:17 -07:00
compat.c net/compat: Update msg_control_is_user when setting a kernel pointer 2023-04-14 11:09:27 +01:00
devres.c
Kconfig net/handshake: Add Kunit tests for the handshake consumer API 2023-04-19 18:48:48 -07:00
Kconfig.debug
Makefile net/handshake: Create a NETLINK service for handling handshake requests 2023-04-19 18:48:48 -07:00
socket.c net: skbuff: hide wifi_acked when CONFIG_WIRELESS not set 2023-04-19 13:04:30 +01:00
sysctl_net.c