INFO: task syz-executor.0:9661 blocked for more than 143 seconds. Not tainted 5.8.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27072 9661 6832 0xa0024006 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0x3a/0x180 drivers/net/tun.c:3421 __fput+0x33c/0x880 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 exit_task_work include/linux/task_work.h:25 [inline] do_exit+0xb72/0x2a40 kernel/exit.c:805 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x40b/0x1ee0 kernel/signal.c:2743 do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810 exit_to_usermode_loop arch/x86/entry/common.c:212 [inline] __prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:246 __do_fast_syscall_32 arch/x86/entry/common.c:448 [inline] do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:474 entry_SYSENTER_compat+0x6d/0x7c arch/x86/entry/entry_64_compat.S:138 RIP: 0023:0xf7f55569 Code: Bad RIP value. RSP: 002b:00000000f5d2f12c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0 RAX: fffffffffffffe00 RBX: 000000000819afd4 RCX: 0000000000000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000819afd8 RBP: 00000000f5d2f228 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor.1:13608 blocked for more than 144 seconds. Not tainted 5.8.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28776 13608 13427 0xa0024006 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0x3a/0x180 drivers/net/tun.c:3421 __fput+0x33c/0x880 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 exit_task_work include/linux/task_work.h:25 [inline] do_exit+0xb72/0x2a40 kernel/exit.c:805 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x40b/0x1ee0 kernel/signal.c:2743 do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810 exit_to_usermode_loop arch/x86/entry/common.c:212 [inline] __prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:246 __do_fast_syscall_32 arch/x86/entry/common.c:448 [inline] do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:474 entry_SYSENTER_compat+0x6d/0x7c arch/x86/entry/entry_64_compat.S:138 RIP: 0023:0xf7f1e569 Code: Bad RIP value. RSP: 002b:00000000f5d1912c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0 RAX: fffffffffffffe00 RBX: 000000000819af68 RCX: 0000000000000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000819af6c RBP: 00000000f5d19228 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: task kworker/u4:6:5725 blocked for more than 144 seconds. Not tainted 5.8.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:6 D25016 5725 2 0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103 ip6gre_exit_batch_net+0x82/0x6c0 net/ipv6/ip6_gre.c:1605 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:189 cleanup_net+0x4ea/0xa00 net/core/net_namespace.c:603 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 INFO: task syz-executor.5:18146 blocked for more than 145 seconds. Not tainted 5.8.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D24856 18146 7400 0x20024004 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1873 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 __flush_work+0x51f/0xab0 kernel/workqueue.c:3046 flush_all_backlogs net/core/dev.c:5632 [inline] rollback_registered_many+0x55b/0xf60 net/core/dev.c:8953 unregister_netdevice_many.part.0+0x1a/0x2f0 net/core/dev.c:10113 unregister_netdevice_many+0x36/0x50 net/core/dev.c:10112 __rtnl_newlink+0x13bd/0x1730 net/core/rtnetlink.c:3380 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3397 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5460 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x331/0x810 net/socket.c:2352 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406 __sys_sendmmsg+0x296/0x480 net/socket.c:2489 __compat_sys_sendmmsg net/compat.c:480 [inline] __do_compat_sys_sendmmsg net/compat.c:487 [inline] __se_compat_sys_sendmmsg net/compat.c:484 [inline] __ia32_compat_sys_sendmmsg+0x9b/0x100 net/compat.c:484 do_syscall_32_irqs_on+0x3f/0x60 arch/x86/entry/common.c:403 __do_fast_syscall_32 arch/x86/entry/common.c:448 [inline] do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:474 entry_SYSENTER_compat+0x6d/0x7c arch/x86/entry/entry_64_compat.S:138 RIP: 0023:0xf7f70569 Code: Bad RIP value. RSP: 002b:00000000f5d290cc EFLAGS: 00000296 ORIG_RAX: 0000000000000159 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000140 RDX: 0000000092492805 RSI: 0000000000004a00 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1148: #0: ffffffff89bc1180 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 7 locks held by kworker/1:1H/2424: 1 lock held by in:imklog/6504: #0: ffff8880a6cc6930 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by agetty/6717: #0: ffff888095916098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000fa02e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 2 locks held by agetty/6718: #0: ffff8880a6ab3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000f342e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/9661: #0: ffffffff8a7b3128 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:704 [inline] #0: ffffffff8a7b3128 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3421 1 lock held by syz-executor.1/13608: #0: ffffffff8a7b3128 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:704 [inline] #0: ffffffff8a7b3128 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3421 3 locks held by kworker/1:2/3388: #0: ffff8880a8886538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a8886538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880a8886538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880a8886538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8880a8886538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8880a8886538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc90003f97da8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8a7b3128 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4543 4 locks held by kworker/u4:6/5725: #0: ffff8880a97ad138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a97ad138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880a97ad138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880a97ad138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8880a97ad138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8880a97ad138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc9000d247da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8a7a62f0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa00 net/core/net_namespace.c:565 #3: ffffffff8a7b3128 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x82/0x6c0 net/ipv6/ip6_gre.c:1605 2 locks held by syz-executor.5/18146: #0: ffffffff8a7b3128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8a7b3128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5457 #1: ffffffff89b7ba10 (cpu_hotplug_lock){++++}-{0:0}, at: get_online_cpus include/linux/cpu.h:143 [inline] #1: ffffffff89b7ba10 (cpu_hotplug_lock){++++}-{0:0}, at: flush_all_backlogs net/core/dev.c:5625 [inline] #1: ffffffff89b7ba10 (cpu_hotplug_lock){++++}-{0:0}, at: rollback_registered_many+0x464/0xf60 net/core/dev.c:8953 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1148 Comm: khungtaskd Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd7d/0x1000 kernel/hung_task.c:295 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2424 Comm: kworker/1:1H Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_highpri snd_vmidi_output_work RIP: 0010:hlock_class kernel/locking/lockdep.c:179 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4079 [inline] RIP: 0010:__lock_acquire+0x763/0x56e0 kernel/locking/lockdep.c:4330 Code: 20 66 81 e2 ff 1f 0f b7 ea be 08 00 00 00 48 89 e8 48 c1 f8 06 48 8d 3c c5 20 fa 58 8c e8 95 38 59 00 48 0f a3 2d 4d 52 ff 0a <0f> 82 3a ff ff ff 48 c7 c0 a0 d1 90 8c 48 c1 e8 03 42 0f b6 14 30 RSP: 0018:ffffc90007c3f7b0 EFLAGS: 00000047 RAX: 0000000000000001 RBX: 0000000000000002 RCX: ffffffff8159a7cb RDX: fffffbfff18b1f53 RSI: 0000000000000008 RDI: ffffffff8c58fa90 RBP: 0000000000000388 R08: 0000000000000000 R09: ffffffff8c58fa97 R10: fffffbfff18b1f52 R11: 0000000000000001 R12: ffff8880a1366040 R13: 0000000000000004 R14: dffffc0000000000 R15: ffff8880a1366910 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00074bc80 CR3: 000000005042d000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:4959 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x2d/0x40 kernel/locking/spinlock.c:223 snd_seq_port_use_ptr+0x38/0x1a0 sound/core/seq/seq_ports.c:51 snd_seq_deliver_single_event.constprop.0+0x1ba/0x820 sound/core/seq/seq_clientmgr.c:615 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:693 [inline] snd_seq_deliver_event+0x2fa/0x850 sound/core/seq/seq_clientmgr.c:828 snd_seq_kernel_client_dispatch+0x145/0x180 sound/core/seq/seq_clientmgr.c:2323 snd_vmidi_output_work+0x1c8/0x380 sound/core/seq/seq_virmidi.c:150 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293