INFO: task kworker/u4:6:8293 blocked for more than 143 seconds. Not tainted 5.8.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:6 D25904 8293 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_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 __cancel_work_timer+0x5de/0x700 kernel/workqueue.c:3133 ovs_exit_net+0x25c/0xba0 net/openvswitch/datapath.c:2496 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:186 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 kworker/0:6:10576 blocked for more than 143 seconds. Not tainted 5.8.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:6 D26424 10576 2 0x00004000 Workqueue: events ovs_dp_masks_rebalance 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 ovs_lock net/openvswitch/datapath.c:105 [inline] ovs_dp_masks_rebalance+0x18/0x80 net/openvswitch/datapath.c:2355 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 Showing all locks held in the system: 1 lock held by khungtaskd/1149: #0: ffffffff89bc0ec0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 1 lock held by in:imklog/6495: #0: ffff8880a2665130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 4 locks held by kworker/u4:6/8293: #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: ffffc90001d67da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8a7ace30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa00 net/core/net_namespace.c:565 #3: ffffffff8aa5d768 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:105 [inline] #3: ffffffff8aa5d768 (ovs_mutex){+.+.}-{3:3}, at: ovs_exit_net+0x1de/0xba0 net/openvswitch/datapath.c:2491 3 locks held by kworker/0:6/10576: #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc90001757da8 ((work_completion)(&(&dp->masks_rebalance)->work)){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8aa5d768 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:105 [inline] #2: ffffffff8aa5d768 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_masks_rebalance+0x18/0x80 net/openvswitch/datapath.c:2355 2 locks held by syz-executor.0/16776: #0: ffffffff8a817710 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:741 #1: ffffffff8aa5d768 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:105 [inline] #1: ffffffff8aa5d768 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_cmd_del+0x4a/0x270 net/openvswitch/datapath.c:1780 2 locks held by syz-executor.0/16785: #0: ffffffff8a817710 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:741 #1: ffffffff8aa5d768 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:105 [inline] #1: ffffffff8aa5d768 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_cmd_del+0x4a/0x270 net/openvswitch/datapath.c:1780 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1149 Comm: khungtaskd Not tainted 5.8.0-rc4-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: 3881 Comm: systemd-journal Not tainted 5.8.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_is_kernel_initmem_freed arch/x86/include/asm/sections.h:27 [inline] RIP: 0010:static_obj+0x35/0xc0 kernel/locking/lockdep.c:755 Code: 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 53 80 3c 10 00 75 7b 48 c7 c0 00 60 62 8d 48 39 e8 0f 97 c3 48 83 3d 1b c8 58 08 00 <75> 2a 48 c7 c0 60 ab b1 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 RSP: 0018:ffffc900016279f8 EFLAGS: 00000246 RAX: ffffffff8d626000 RBX: ffffffff8c921101 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff884b9920 RDI: ffffffff8be8d440 RBP: ffffffff8be8d440 R08: 0000000000000002 R09: 0000000000000000 R10: ffffed10127689b9 R11: 0000000000000000 R12: ffffffff8be8d440 R13: 0000000000000000 R14: ffffffff8c941c80 R15: 00000000ffffff9c FS: 00007efca07f68c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efc9dc9a018 CR3: 0000000093b6c000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_init_map_waits+0x26a/0x890 kernel/locking/lockdep.c:4163 lockdep_init_map_wait include/linux/lockdep.h:349 [inline] __raw_spin_lock_init+0x34/0x100 kernel/locking/spinlock_debug.c:24 __mutex_init+0x5d/0x120 kernel/locking/mutex.c:43 __alloc_file+0x181/0x350 fs/file_table.c:115 alloc_empty_file+0x6d/0x170 fs/file_table.c:151 path_openat+0xe3/0x2750 fs/namei.c:3346 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179 do_sys_open fs/open.c:1195 [inline] ksys_open include/linux/syscalls.h:1388 [inline] __do_sys_open fs/open.c:1201 [inline] __se_sys_open fs/open.c:1199 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1199 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7efc9fd86840 Code: Bad RIP value. RSP: 002b:00007fff3f8338f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fff3f833c00 RCX: 00007efc9fd86840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005570889d5a90 RBP: 000000000000000d R08: 000000000000ffc0 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 00005570889c9040 R14: 00007fff3f833bc0 R15: 00005570889d5ae0