INFO: task kworker/1:20:2921 blocked for more than 143 seconds. Not tainted 5.5.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:20 D26208 2921 2 0x80004000 Workqueue: events switchdev_deferred_process_work Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4214 __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+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/1:3:17851 blocked for more than 144 seconds. Not tainted 5.5.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:3 D26208 17851 2 0x80004000 Workqueue: events linkwatch_event Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4214 __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+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 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: 2 locks held by kworker/u4:5/850: 1 lock held by khungtaskd/1128: #0: ffffffff899a3e00 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5333 3 locks held by kworker/1:20/2921: #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:226 [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:855 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [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+0x88b/0x1740 kernel/workqueue.c:2235 #1: ffffc90008f97dc0 (deferred_process_work){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2239 #2: ffffffff8a4e3300 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by rsyslogd/9416: #0: ffff8880971beb20 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/9506: #0: ffff88809fc62090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000179b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9507: #0: ffff8880986db090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000181b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9508: #0: ffff8880a7c3b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900017bb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9509: #0: ffff8880a70ac090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900017eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9510: #0: ffff88809fd4f090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000180b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9511: #0: ffff8880949fc090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000182b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9512: #0: ffff8880a25b2090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900017732e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:2/7701: 4 locks held by kworker/u4:3/10050: 3 locks held by syz-executor.4/13513: 2 locks held by kworker/1:1/17850: #0: ffff8880ae937358 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #0: ffff8880ae937358 (&rq->lock){-.-.}, at: __schedule+0x232/0x1f90 kernel/sched/core.c:4029 #1: ffffffff899a3e00 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:435 [inline] #1: ffffffff899a3e00 (rcu_read_lock){....}, at: update_curr+0x2ea/0x8d0 kernel/sched/fair.c:859 3 locks held by kworker/1:3/17851: #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:226 [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:855 [inline] #0: ffff8880aa426d28 ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [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+0x88b/0x1740 kernel/workqueue.c:2235 #1: ffffc900016f7dc0 ((linkwatch_work).work){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2239 #2: ffffffff8a4e3300 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.1/7179: 1 lock held by syz-executor.0/8039: 3 locks held by kworker/1:2/16861: #0: ffff8880a7978128 ((wq_completion)ipv6_addrconf){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a7978128 ((wq_completion)ipv6_addrconf){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a7978128 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a7978128 ((wq_completion)ipv6_addrconf){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a7978128 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880a7978128 ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880a7978128 ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2235 #1: ffffc90001947dc0 ((addr_chk_work).work){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2239 #2: ffffffff8a4e3300 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 3 locks held by syz-executor.5/24442: 3 locks held by syz-executor.1/24465: 3 locks held by syz-executor.1/24473: #0: ffff8880756f1da0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: ffff888214d0a428 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2885 [inline] #1: ffff888214d0a428 (sb_writers#3){.+.+}, at: vfs_write+0x485/0x5d0 fs/read_write.c:557 #2: ffff88805bd7a8c8 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:791 [inline] #2: ffff88805bd7a8c8 (&sb->s_type->i_mutex_key#11){+.+.}, at: ext4_buffered_write_iter+0xba/0x460 fs/ext4/file.c:246 2 locks held by syz-executor.3/24481: 1 lock held by syz-executor.4/24484: #0: ffff8880ae837358 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #0: ffff8880ae837358 (&rq->lock){-.-.}, at: __schedule+0x232/0x1f90 kernel/sched/core.c:4029 1 lock held by syz-executor.5/24487: #0: ffff8880ae937358 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #0: ffff8880ae937358 (&rq->lock){-.-.}, at: __schedule+0x232/0x1f90 kernel/sched/core.c:4029 3 locks held by syz-executor.5/24497: 3 locks held by syz-executor.2/24500: 3 locks held by syz-executor.2/24502: #0: ffff8880a64373e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: ffff888214d0a428 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2885 [inline] #1: ffff888214d0a428 (sb_writers#3){.+.+}, at: vfs_write+0x485/0x5d0 fs/read_write.c:557 #2: ffff88805bc7b608 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:791 [inline] #2: ffff88805bc7b608 (&sb->s_type->i_mutex_key#11){+.+.}, at: ext4_buffered_write_iter+0xba/0x460 fs/ext4/file.c:246 2 locks held by syz-executor.4/24506: #0: ffff8880a7de9350 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0xe9a/0x2c00 kernel/events/core.c:11257 #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: account_event kernel/events/core.c:10636 [inline] #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: perf_event_alloc.part.0+0x2d73/0x3710 kernel/events/core.c:10859 2 locks held by syz-executor.0/24511: #0: ffff8880a796a590 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0xe9a/0x2c00 kernel/events/core.c:11257 #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: account_event kernel/events/core.c:10636 [inline] #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: perf_event_alloc.part.0+0x2d73/0x3710 kernel/events/core.c:10859 2 locks held by syz-executor.1/24515: #0: ffff8880a68fac10 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0xe9a/0x2c00 kernel/events/core.c:11257 #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: account_event kernel/events/core.c:10636 [inline] #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: perf_event_alloc.part.0+0x2d73/0x3710 kernel/events/core.c:10859 3 locks held by syz-executor.1/24516: 2 locks held by syz-executor.3/24521: #0: ffff88809ec65210 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0xe9a/0x2c00 kernel/events/core.c:11257 #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: account_event kernel/events/core.c:10636 [inline] #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: perf_event_alloc.part.0+0x2d73/0x3710 kernel/events/core.c:10859 1 lock held by syz-executor.3/24523: 3 locks held by syz-executor.5/24522: 2 locks held by syz-executor.2/24530: #0: ffff8880632bed90 (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0xe9a/0x2c00 kernel/events/core.c:11257 #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: account_event kernel/events/core.c:10636 [inline] #1: ffffffff89a10980 (perf_sched_mutex){+.+.}, at: perf_event_alloc.part.0+0x2d73/0x3710 kernel/events/core.c:10859 3 locks held by syz-executor.2/24531: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1128 Comm: khungtaskd Not tainted 5.5.0-rc6-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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb11/0x10c0 kernel/hung_task.c:289 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: 24510 Comm: syz-executor.1 Not tainted 5.5.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0033:0x4101b8 Code: e8 08 48 39 ca 76 0f 0f 1f 00 48 83 e8 08 48 8b 10 48 39 ca 77 f4 48 39 e8 76 18 48 89 57 f8 4c 89 00 48 8b 50 f8 49 8b 0c 24 <4c> 8b 07 48 83 c7 08 eb bf 4c 89 ea 48 89 ef e8 34 ff ff ff 48 89 RSP: 002b:00007ffd743a9170 EFLAGS: 00000216 RAX: 00007ff0d8941f98 RBX: 00007ff0d892de88 RCX: ffffffff87d6b594 RDX: ffffffff87d6b714 RSI: 00007ff0d8945720 RDI: 00007ff0d893b0d0 RBP: 00007ff0d893b0c8 R08: ffffffff87d699a9 R09: 00000000c7174e24 R10: 00007ffd743a93a0 R11: 0000000000000246 R12: 00007ff0d892de78 R13: 000000000000001d R14: 00007ff0d893b0c8 R15: 000000000003ffff FS: 0000000002a37940 GS: 0000000000000000