bisecting fixing commit since fb893de323e2d39f7a1f6df425703a2edbdf56ea
building syzkaller on bc15f7dbbc1c6e2042a7115b3fdacc0ada8c35e7
testing commit fb893de323e2d39f7a1f6df425703a2edbdf56ea with gcc (GCC) 8.4.1 20210217
kernel signature: 2bee816e6fc05d6cb4590f5e8ed0dd0b4185585a4fe74e4e09c5420383f2eaf0
run #0: crashed: BUG: soft lockup in smp_call_function
run #1: crashed: BUG: soft lockup in do_idle
run #2: crashed: BUG: soft lockup in linkwatch_event
run #3: crashed: BUG: workqueue lockup
run #4: crashed: BUG: workqueue lockup
run #5: crashed: BUG: soft lockup in do_idle
run #6: crashed: BUG: soft lockup in do_idle
run #7: crashed: BUG: workqueue lockup
run #8: crashed: BUG: soft lockup in security_file_open
run #9: crashed: BUG: workqueue lockup
run #10: crashed: BUG: soft lockup in rtnl_newlink
run #11: crashed: BUG: soft lockup in do_idle
run #12: crashed: BUG: soft lockup in do_idle
run #13: crashed: BUG: soft lockup in do_unlinkat
run #14: crashed: BUG: soft lockup in do_idle
run #15: crashed: INFO: rcu detected stall in do_faccessat
run #16: crashed: BUG: soft lockup in newlstat
run #17: crashed: INFO: rcu detected stall in mutex_spin_on_owner
run #18: crashed: BUG: soft lockup in do_idle
run #19: crashed: no output from test machine
testing current HEAD 1678e493d530e7977cce34e59a86bb86f3c5631e
testing commit 1678e493d530e7977cce34e59a86bb86f3c5631e with gcc (GCC) 10.2.1 20210217
kernel signature: af0c6a6c18fa2d088190033b98ea947f23eab5355416d91a43e0efd569e49959
run #0: crashed: BUG: soft lockup in smp_call_function
run #1: crashed: BUG: soft lockup in do_idle
run #2: crashed: BUG: workqueue lockup
run #3: crashed: BUG: soft lockup in smp_call_function
run #4: basic kernel testing failed: failed to copy test binary to VM: failed to run ["scp" "-P" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "BatchMode=yes" "-o" "IdentitiesOnly=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "/tmp/syz-executor278901886" "root@10.128.10.1:./syz-executor278901886"]: exit status 1
ssh: connect to host 10.128.10.1 port 22: Connection timed out
lost connection

run #5: crashed: INFO: rcu detected stall in do_idle
run #6: crashed: INFO: rcu detected stall in do_idle
run #7: crashed: INFO: rcu detected stall in do_idle
run #8: crashed: BUG: workqueue lockup
run #9: crashed: BUG: workqueue lockup
revisions tested: 2, total time: 26m31.231166105s (build: 11m30.603754253s, test: 14m10.814902166s)
the crash still happens on HEAD
commit msg: Merge tag 'lto-v5.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
crash: BUG: workqueue lockup
BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 49s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=5/256 refcnt=6
    in-flight: 7417:nsim_fib_event_work, 3302:nsim_fib_event_work, 6023:nsim_fib_event_work nsim_fib_event_work
    pending: nsim_fib_event_work
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256 refcnt=3
    in-flight: 7383:linkwatch_event
    pending: nsim_dev_trap_report_work
workqueue events_power_efficient: flags=0x80
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: check_lifetime
workqueue rcu_gp: flags=0x8
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    in-flight: 7415:wait_rcu_exp_gp
workqueue writeback: flags=0x4a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=3
    in-flight: 6805:wb_workfn
workqueue ipv6_addrconf: flags=0x40008
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=175
    in-flight: 19:addrconf_dad_work
    delayed: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=111
    in-flight: 7378:addrconf_dad_work
    delayed: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
workqueue bat_events: flags=0xe000a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=7
    pending: batadv_iv_send_outstanding_bat_ogm_packet
    delayed: batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker
workqueue wg-crypt-wg0: flags=0x28
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: wg_packet_encrypt_worker
workqueue wg-crypt-wg1: flags=0x28
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3
    pending: wg_packet_encrypt_worker, wg_packet_decrypt_worker
workqueue wg-crypt-wg2: flags=0x28
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker, wg_packet_tx_worker
pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=0s workers=8 idle: 2631 5 1311 7416 11
pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=49s workers=9 idle: 7394 7418 49 7395 7391
pool 4: cpus=0-1 flags=0x4 nice=0 hung=0s workers=6 idle: 26 24 125 7 158
BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 79s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=5/256 refcnt=6
    in-flight: 7417:nsim_fib_event_work, 3302:nsim_fib_event_work, 6023:nsim_fib_event_work nsim_fib_event_work
    pending: nsim_fib_event_work
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    in-flight: 7383:linkwatch_event
workqueue events_power_efficient: flags=0x80
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: check_lifetime
workqueue rcu_gp: flags=0x8
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    in-flight: 7415:wait_rcu_exp_gp
workqueue writeback: flags=0x4a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=3
    in-flight: 6805:wb_workfn
workqueue ipv6_addrconf: flags=0x40008
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=175
    in-flight: 19:addrconf_dad_work
    delayed: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=111
    in-flight: 7378:addrconf_dad_work
    delayed: addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work, addrconf_dad_work
workqueue wg-crypt-wg0: flags=0x28
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: wg_packet_encrypt_worker
workqueue wg-crypt-wg1: flags=0x28
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3
    pending: wg_packet_encrypt_worker, wg_packet_decrypt_worker
workqueue wg-crypt-wg2: flags=0x28
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker, wg_packet_tx_worker
pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=0s workers=8 idle: 2631 5 1311 7416 11
pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=79s workers=9 idle: 7394 7418 49 7395 7391
pool 4: cpus=0-1 flags=0x4 nice=0 hung=0s workers=6 idle: 26 24 125 7 158
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...0: (1 GPs behind) idle=3d2/1/0x4000000000000000 softirq=8969/8971 fqs=5248 
	(detected by 0, t=10502 jiffies, g=6761, q=942)

============================================
WARNING: possible recursive locking detected
5.12.0-rc5-syzkaller #0 Not tainted
--------------------------------------------
swapper/0/0 is trying to acquire lock:
ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: rcu_dump_cpu_stacks+0x84/0x24a kernel/rcu/tree_stall.h:336

but task is already holding lock:
ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:541 [inline]
ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:706 [inline]
ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3830 [inline]
ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: rcu_sched_clock_irq.cold+0x2b2/0x10b4 kernel/rcu/tree.c:2650

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(rcu_node_0);
  lock(rcu_node_0);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

1 lock held by swapper/0/0:
 #0: ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:541 [inline]
 #0: ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:706 [inline]
 #0: ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3830 [inline]
 #0: ffffffff894c7158 (rcu_node_0){-.-.}-{2:2}, at: rcu_sched_clock_irq.cold+0x2b2/0x10b4 kernel/rcu/tree.c:2650

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x10c/0x14b lib/dump_stack.c:120
 print_deadlock_bug kernel/locking/lockdep.c:2829 [inline]
 check_deadlock kernel/locking/lockdep.c:2872 [inline]
 validate_chain kernel/locking/lockdep.c:3661 [inline]
 __lock_acquire.cold+0x227/0x3a6 kernel/locking/lockdep.c:4900
 lock_acquire kernel/locking/lockdep.c:5510 [inline]
 lock_acquire+0x212/0x850 kernel/locking/lockdep.c:5475
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x94/0xd0 kernel/locking/spinlock.c:159
 rcu_dump_cpu_stacks+0x84/0x24a kernel/rcu/tree_stall.h:336
 print_other_cpu_stall kernel/rcu/tree_stall.h:559 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:706 [inline]
 rcu_pending kernel/rcu/tree.c:3830 [inline]
 rcu_sched_clock_irq.cold+0x859/0x10b4 kernel/rcu/tree.c:2650
 update_process_times+0x131/0x1a0 kernel/time/timer.c:1796
 tick_sched_handle+0x6f/0x130 kernel/time/tick-sched.c:226
 tick_sched_timer+0x132/0x210 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x19e/0xb90 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x2ef/0x900 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x13e/0x520 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:52
Code: e8 b7 4c 34 fa e9 e4 fe ff ff 48 89 df e8 aa 4c 34 fa eb 9c cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 14 59 58 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 04 59 58 00 f4 c3 cc cc 55 53 e8 f9
RSP: 0018:ffffffff89207d70 EFLAGS: 00000286
RAX: 1ffffffff126dec1 RBX: ffff888104653865 RCX: 1ffffffff1486349
RDX: dffffc0000000000 RSI: ffffffff87cb2740 RDI: ffffffff88129500
RBP: ffffffff8929a4c0 R08: 0000000000000001 R09: 0000000000000001
R10: fffffbfff1253498 R11: 0000000000000001 R12: 0000000000000001
R13: ffffffff89a7a8c0 R14: ffff888104653864 R15: ffff8881088c7004
 arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline]
 acpi_idle_do_entry+0x189/0x290 drivers/acpi/processor_idle.c:516
 acpi_idle_enter+0x2d4/0x4a0 drivers/acpi/processor_idle.c:647
 cpuidle_enter_state+0x145/0x990 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x45/0xa0 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x48e/0x730 kernel/sched/idle.c:300
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:397
 start_kernel+0x34a/0x368 init/main.c:1064
 secondary_startup_64_no_verify+0xb0/0xbb