INFO: task syz-executor.3:6125 blocked for more than 143 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:24120 pid: 6125 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0xfc4/0x2260 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 wb_wait_for_completion+0x15a/0x200 fs/fs-writeback.c:209 sync_inodes_sb+0x18b/0x8a0 fs/fs-writeback.c:2577 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x10b/0x1f0 fs/sync.c:48 generic_shutdown_super+0x64/0x320 fs/super.c:448 kill_block_super+0x90/0xd0 fs/super.c:1394 deactivate_locked_super+0x7b/0x130 fs/super.c:335 cleanup_mnt+0x326/0x4c0 fs/namespace.c:1136 task_work_run+0xc0/0x160 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x240/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x40/0x80 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466ca7 RSP: 002b:00007fff143849b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007fff14384a89 RSI: 0000000000000002 RDI: 00007fff14384a80 RBP: 00007fff14384a80 R08: 00000000ffffffff R09: 00007fff14384850 R10: 00000000017fe8e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007fff14385b30 R14: 00000000017fe810 R15: 0000000000000002 INFO: task syz-executor.1:6133 blocked for more than 143 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:23944 pid: 6133 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0xfc4/0x2260 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 wb_wait_for_completion+0x15a/0x200 fs/fs-writeback.c:209 sync_inodes_sb+0x18b/0x8a0 fs/fs-writeback.c:2577 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x10b/0x1f0 fs/sync.c:48 generic_shutdown_super+0x64/0x320 fs/super.c:448 kill_block_super+0x90/0xd0 fs/super.c:1394 deactivate_locked_super+0x7b/0x130 fs/super.c:335 cleanup_mnt+0x326/0x4c0 fs/namespace.c:1136 task_work_run+0xc0/0x160 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x240/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x40/0x80 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466ca7 RSP: 002b:00007fffe2308538 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007fffe2308609 RSI: 0000000000000002 RDI: 00007fffe2308600 RBP: 00007fffe2308600 R08: 00000000ffffffff R09: 00007fffe23083d0 R10: 0000000001d708e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007fffe23096b0 R14: 0000000001d70810 R15: 0000000000000002 INFO: task syz-executor.2:6134 blocked for more than 143 seconds. Not tainted 5.12.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:23584 pid: 6134 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0xfc4/0x2260 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 wb_wait_for_completion+0x15a/0x200 fs/fs-writeback.c:209 sync_inodes_sb+0x18b/0x8a0 fs/fs-writeback.c:2577 __sync_filesystem fs/sync.c:34 [inline] sync_filesystem fs/sync.c:67 [inline] sync_filesystem+0x10b/0x1f0 fs/sync.c:48 generic_shutdown_super+0x64/0x320 fs/super.c:448 kill_block_super+0x90/0xd0 fs/super.c:1394 deactivate_locked_super+0x7b/0x130 fs/super.c:335 cleanup_mnt+0x326/0x4c0 fs/namespace.c:1136 task_work_run+0xc0/0x160 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x240/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x40/0x80 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466ca7 RSP: 002b:00007ffce5db12d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466ca7 RDX: 00007ffce5db13a9 RSI: 0000000000000002 RDI: 00007ffce5db13a0 RBP: 00007ffce5db13a0 R08: 00000000ffffffff R09: 00007ffce5db1170 R10: 00000000029058e3 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007ffce5db2450 R14: 0000000002905810 R15: 0000000000000002 Showing all locks held in the system: 2 locks held by kworker/u4:1/24: #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2246 #1: ffffc900001b7db0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2250 2 locks held by kworker/u4:3/137: #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2246 #1: ffffc90000807db0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2250 2 locks held by kworker/u4:4/194: #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888103ea1138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x771/0x13d0 kernel/workqueue.c:2246 #1: ffffc900006e7db0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0x13d0 kernel/workqueue.c:2250 3 locks held by kworker/u4:5/237: #0: ffff8881f62365d8 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x7f8/0xea0 kernel/sched/fair.c:10633 #1: ffffffff89dae140 (rcu_read_lock){....}-{1:2}, at: cpu_of kernel/sched/sched.h:1086 [inline] #1: ffffffff89dae140 (rcu_read_lock){....}-{1:2}, at: __update_idle_core+0x39/0x470 kernel/sched/fair.c:6045 #2: ffff8881f6225118 (&base->lock){..-.}-{2:2}, at: lock_timer_base+0x49/0x1a0 kernel/time/timer.c:944 1 lock held by khungtaskd/1202: #0: ffffffff89dae140 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c kernel/locking/lockdep.c:6327 1 lock held by in:imklog/5789: #0: ffff888114e13db0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x9c/0xb0 fs/file.c:961 2 locks held by syz-executor.3/6125: #0: ffff88811b9040e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: deactivate_super+0x5f/0x80 fs/super.c:365 #1: ffff88810c2ac708 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:344 [inline] #1: ffff88810c2ac708 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x171/0x8a0 fs/fs-writeback.c:2575 2 locks held by syz-executor.1/6133: #0: ffff8881048920e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: deactivate_super+0x5f/0x80 fs/super.c:365 #1: ffff88810c1e8708 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:344 [inline] #1: ffff88810c1e8708 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x171/0x8a0 fs/fs-writeback.c:2575 2 locks held by syz-executor.2/6134: #0: ffff8881155840e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: deactivate_super+0x5f/0x80 fs/super.c:365 #1: ffff88810c26a708 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:344 [inline] #1: ffff88810c26a708 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x171/0x8a0 fs/fs-writeback.c:2575 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1202 Comm: khungtaskd Not tainted 5.12.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x10c/0x14b lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x2d/0xac lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x11f/0x170 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+0x9cf/0xc00 kernel/hung_task.c:294 kthread+0x36f/0x450 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 5.12.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:check_wait_context kernel/locking/lockdep.c:4596 [inline] RIP: 0010:__lock_acquire+0x6a6/0x5500 kernel/locking/lockdep.c:4850 Code: 06 0f 8e 9d 2b 00 00 0f b6 80 b8 00 00 00 84 c0 74 07 41 38 c6 44 0f 47 f0 48 8b 04 24 41 83 c4 01 48 c1 e8 03 42 0f b6 04 38 <84> c0 74 08 3c 03 0f 8e 60 2b 00 00 45 3b a5 90 09 00 00 0f 8d 99 RSP: 0000:ffffc9000015f8d8 EFLAGS: 00000806 RAX: 0000000000000000 RBX: ffff88810089ee98 RCX: ffffffff8155b96c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d3cb738 RBP: 00000000000000c9 R08: 0000000000000000 R09: ffffffff8d3c1bbf R10: fffffbfff1a78377 R11: 00000000a9d27ff0 R12: 0000000000000001 R13: ffff88810089e500 R14: 0000000000000004 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fba14e0f000 CR3: 000000010135a005 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x212/0x860 kernel/locking/lockdep.c:5475 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x94/0xd0 kernel/locking/spinlock.c:159 _crng_backtrack_protect+0x4d/0x150 drivers/char/random.c:1045 crng_backtrack_protect drivers/char/random.c:1063 [inline] _get_random_bytes+0x1f7/0x550 drivers/char/random.c:1551 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:541 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:570 [inline] nsim_dev_trap_report_work+0x710/0xb50 drivers/net/netdevsim/dev.c:611 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2275 worker_thread+0x598/0xf80 kernel/workqueue.c:2421 kthread+0x36f/0x450 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294