INFO: task syz.0.1991:13892 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1991      state:D stack:22456 pid:13892 tgid:13891 ppid:12364  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 ppp_ioctl+0x695/0x19a0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f73f178eba9
RSP: 002b:00007f73f254f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f73f19d5fa0 RCX: 00007f73f178eba9
RDX: 000000110c230000 RSI: 00000000c004743e RDI: 000000000000000b
RBP: 00007f73f1811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f73f19d6038 R14: 00007f73f19d5fa0 R15: 00007ffed21cc3a8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5593:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20
2 locks held by getty/5674:
 #0: ffff8881100df0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u8:2/5696:
 #0: ffff888109d18948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000307fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
7 locks held by kworker/u11:2/5850:
 #0: ffff888118265948 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000370fbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88803c38cdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0
 #3: ffff88803c38c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x242/0xe30
 #4: ffffffff8f69efc8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x310
 #5: ffff888039e99338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680
 #6: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
3 locks held by kworker/1:7/7730:
 #0: ffff88801a482148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000293fbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x95/0xf30
2 locks held by syz.2.1988/13872:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
6 locks held by syz.1.1990/13883:
2 locks held by syz.0.1991/13892:
 #0: ffffffff8ecf8e88 (ppp_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xcd/0x19a0
 #1: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: ppp_ioctl+0x695/0x19a0
1 lock held by syz-executor/13896:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/13900:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/13903:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/13910:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/13914:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/13921:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/13931:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/13935:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0
1 lock held by syz-executor/13942:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13883 Comm: syz.1.1990 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_read_unlock_special+0x20a/0x4b0
Code: 08 4c 89 ff e8 17 6f 7c 00 4d 8b 3f 49 83 c4 78 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 fa 6e 7c 00 4d 85 3c 24 <41> 0f 94 c4 80 3d 7b bf 6c 0c 01 75 27 f7 44 24 08 00 02 00 00 0f
RSP: 0018:ffffc900001e0220 EFLAGS: 00000002
RAX: 1ffffffff1c27e8f RBX: 1ffff9200003c048 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff8be33de0 RDI: ffffffff8be33da0
RBP: ffffc900001e02f8 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffffffff8e13f478
R13: dffffc0000000000 R14: ffff88813663af80 R15: 0000000000000002
FS:  00007fc51998b6c0(0000) GS:ffff8881a3c12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558b5121cd00 CR3: 0000000027754000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x84/0xe0
 unwind_next_frame+0x19ae/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_mempool_unpoison_object+0xa0/0x170
 napi_skb_cache_get+0x37b/0x6d0
 __alloc_skb+0x11e/0x2d0
 napi_alloc_skb+0x84/0x7d0
 e1000_clean_rx_irq+0x448/0x1170
 e1000_clean+0xca4/0x2b00
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__schedule+0x7f/0x4cc0
Code: 6c 31 a7 8d 48 c7 84 24 10 01 00 00 b0 ce 7b 8b 48 8d 8c 24 00 01 00 00 48 c1 e9 03 48 b8 f1 f1 f1 f1 04 f2 00 00 4a 89 04 31 <48> b8 f2 f2 f2 f2 f2 00 f2 f2 4a 89 44 31 09 42 c7 44 31 11 f2 00
RSP: 0018:ffffc90007347640 EFLAGS: 00000a06
RAX: 0000f204f1f1f1f1 RBX: ffff88803f5e1cc0 RCX: 1ffff92000e68ee8
RDX: 0000000000000007 RSI: ffffffff8d9ba3cb RDI: ffffc900073477d0
RBP: ffffc90007347850 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: 0000000000000000
R13: 0000000000000001 R14: dffffc0000000000 R15: 1ffff92000e68f0c
 preempt_schedule_irq+0xb5/0x150
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__slab_free+0x251/0x3c0
Code: ea 48 8b 4c 24 10 4d 89 f8 e8 1b e1 ff ff 41 89 c7 e9 44 fe ff ff 48 8b 5c 24 10 4c 89 f9 4c 89 e0 4c 89 ea f0 48 0f c7 4e 20 <0f> 85 95 fe ff ff 48 85 ed 75 2c 45 85 ed 79 57 65 48 8b 05 07 8c
RSP: 0018:ffffc900073479d8 EFLAGS: 00000242
RAX: ffff888120f54000 RBX: ffff888120f54180 RCX: 0000000000150013
RDX: 0000000000150014 RSI: ffffea000483d500 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffff888120f54000
R13: 0000000000150014 R14: ffff8881016eb8c0 R15: 0000000000150013
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 security_file_alloc+0x34/0x330
 init_file+0x93/0x2f0
 alloc_empty_file+0x6e/0x1d0
 alloc_file_pseudo+0x13d/0x210
 anon_inode_getfile+0xc5/0x1a0
 __se_sys_perf_event_open+0xf20/0x1d70
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc518b8eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc51998b038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fc518dd6090 RCX: 00007fc518b8eba9
RDX: bfffffffffffffff RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007fc518c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc518dd6128 R14: 00007fc518dd6090 R15: 00007fffc2f37e38
 </TASK>
