INFO: task kworker/1:1:16699 blocked for more than 143 seconds. Not tainted 5.6.0-rc2-next-20200219-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:1 D26216 16699 2 0x80004000 Workqueue: events linkwatch_event Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4080 schedule+0xdc/0x2b0 kernel/sched/core.c:4154 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 linkwatch_event+0xf/0x70 net/core/link_watch.c:242 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2266 worker_thread+0x98/0xe40 kernel/workqueue.c:2412 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/1:2:16700 blocked for more than 143 seconds. Not tainted 5.6.0-rc2-next-20200219-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:2 D26216 16700 2 0x80004000 Workqueue: events switchdev_deferred_process_work Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4080 schedule+0xdc/0x2b0 kernel/sched/core.c:4154 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:74 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2266 worker_thread+0x98/0xe40 kernel/workqueue.c:2412 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 4 locks held by kworker/u4:0/7: 2 locks held by kworker/u4:2/24: 1 lock held by khungtaskd/1103: #0: ffffffff89bad480 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5546 3 locks held by kworker/1:95/3127: #0: ffff88809b399928 ((wq_completion)ipv6_addrconf){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff88809b399928 ((wq_completion)ipv6_addrconf){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88809b399928 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88809b399928 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88809b399928 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88809b399928 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88809b399928 ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2237 #1: ffffc900013e7dc0 ((addr_chk_work).work){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2241 #2: ffffffff8a754dc0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/0:7/3415: #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2237 #1: ffffc90001c37dc0 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2241 #2: ffffffff89bb1298 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x47/0x460 kernel/rcu/tree.c:3322 1 lock held by rsyslogd/9521: #0: ffff88809a532120 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:821 2 locks held by getty/9611: #0: ffff88809e911090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005deb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9612: #0: ffff8880a33e9090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005dcb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9613: #0: ffff8880a6a99090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005ddb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9614: #0: ffff8880a6a5b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005d8b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9615: #0: ffff8880a891a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005e0b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9616: #0: ffff88809fcf5090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005dfb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9617: #0: ffff8880a289b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005d4b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by kworker/1:0/16643: #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2237 #1: ffffc90007cc7dc0 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2241 3 locks held by kworker/1:1/16699: #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2237 #1: ffffc90007cb7dc0 ((linkwatch_work).work){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2241 #2: ffffffff8a754dc0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/1:2/16700: #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2237 #1: ffffc90007ca7dc0 (deferred_process_work){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2241 #2: ffffffff8a754dc0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.0/7445: #0: ffffffff89bb1298 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x47/0x460 kernel/rcu/tree.c:3322 1 lock held by syz-executor.2/7671: #0: ffffffff89bb1298 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x47/0x460 kernel/rcu/tree.c:3322 1 lock held by syz-executor.3/7686: #0: ffffffff89bb1298 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x47/0x460 kernel/rcu/tree.c:3322 1 lock held by syz-executor.4/7936: #0: ffffffff89bb1298 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x47/0x460 kernel/rcu/tree.c:3322 1 lock held by syz-executor.5/7940: #0: ffffffff89bb1298 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x47/0x460 kernel/rcu/tree.c:3322 1 lock held by syz-executor.1/7938: #0: ffffffff89bb1298 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x47/0x460 kernel/rcu/tree.c:3322 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1103 Comm: khungtaskd Not tainted 5.6.0-rc2-next-20200219-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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:249 [inline] watchdog+0xdf1/0x14e0 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 248 Comm: kworker/u4:4 Not tainted 5.6.0-rc2-next-20200219-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:_raw_spin_lock_bh+0x3f/0x50 kernel/locking/spinlock.c:176 Code: 52 f9 49 8d 7c 24 18 45 31 c9 31 c9 ff 75 08 41 b8 01 00 00 00 31 d2 31 f6 e8 ed 43 66 f9 4c 89 e7 e8 b5 35 67 f9 4c 8b 65 f8 <58> c9 c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 RSP: 0018:ffffc90001237c30 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffff888052588ce8 RCX: ffffffff815c6f49 RDX: 1ffff1100a4b119f RSI: 0000000000000004 RDI: ffffc90001237bb8 RBP: ffffc90001237c40 R08: 0000000000000004 R09: fffff52000246f78 R10: fffff52000246f77 R11: 0000000000000003 R12: ffff88808facd1d8 R13: dffffc0000000000 R14: ffffffff87d5c330 R15: 000000000000003b FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000204f9fe4 CR3: 000000005ebf3000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_lock_bh include/linux/spinlock.h:343 [inline] batadv_nc_purge_paths+0xd8/0x370 net/batman-adv/network-coding.c:441 batadv_nc_worker+0x2ca/0x760 net/batman-adv/network-coding.c:721 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2266 worker_thread+0x98/0xe40 kernel/workqueue.c:2412 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352