INFO: task syz-executor.3:15859 can't die for more than 143 seconds. task:syz-executor.3 state:D stack:27888 pid:15859 ppid: 8527 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854 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/0xac0 kernel/workqueue.c:3052 __cancel_work_timer+0x3b3/0x520 kernel/workqueue.c:3139 p9_conn_destroy net/9p/trans_fd.c:891 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:921 p9_client_destroy+0xbe/0x360 net/9p/client.c:1088 v9fs_session_init+0xfd2/0x1770 fs/9p/v9fs.c:482 v9fs_mount+0x79/0x9b0 fs/9p/vfs_super.c:126 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1496 do_new_mount fs/namespace.c:2899 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3230 do_mount fs/namespace.c:3243 [inline] __do_sys_mount fs/namespace.c:3451 [inline] __se_sys_mount fs/namespace.c:3428 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3428 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 RSP: 002b:00007fa1db353c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000119c078 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffee35d5b5f R14: 00007fa1db3549c0 R15: 000000000119c034 INFO: task syz-executor.3:15859 blocked for more than 143 seconds. Not tainted 5.10.0-next-20201223-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:27888 pid:15859 ppid: 8527 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854 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/0xac0 kernel/workqueue.c:3052 __cancel_work_timer+0x3b3/0x520 kernel/workqueue.c:3139 p9_conn_destroy net/9p/trans_fd.c:891 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:921 p9_client_destroy+0xbe/0x360 net/9p/client.c:1088 v9fs_session_init+0xfd2/0x1770 fs/9p/v9fs.c:482 v9fs_mount+0x79/0x9b0 fs/9p/vfs_super.c:126 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1496 do_new_mount fs/namespace.c:2899 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3230 do_mount fs/namespace.c:3243 [inline] __do_sys_mount fs/namespace.c:3451 [inline] __se_sys_mount fs/namespace.c:3428 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3428 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 RSP: 002b:00007fa1db353c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000119c078 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffee35d5b5f R14: 00007fa1db3549c0 R15: 000000000119c034 Showing all locks held in the system: 1 lock held by khungtaskd/1661: #0: ffffffff8b363660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8193: #0: ffff888024fe05f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:949 3 locks held by rs:main Q:Reg/8194: #0: ffff8880b9f34c58 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x789/0xe50 kernel/sched/fair.c:10642 #1: ffffffff8b363660 (rcu_read_lock){....}-{1:2}, at: cpu_of kernel/sched/sched.h:1085 [inline] #1: ffffffff8b363660 (rcu_read_lock){....}-{1:2}, at: __update_idle_core+0x39/0x430 kernel/sched/fair.c:6042 #2: ffff88802e5e6888 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline] #2: ffff88802e5e6888 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: ext4_buffered_write_iter+0xb6/0x4d0 fs/ext4/file.c:264 2 locks held by kworker/1:2/8982: #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888010062d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc900024cfda8 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1661 Comm: khungtaskd Not tainted 5.10.0-next-20201223-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+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:338 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 20 Comm: kworker/1:0 Not tainted 5.10.0-next-20201223-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient gc_worker RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:177 [inline] RIP: 0010:check_memory_region+0xde/0x180 mm/kasan/generic.c:186 Code: 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 48 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00 <74> f2 eb d4 41 bc 08 00 00 00 48 89 ea 45 29 dc 4d 8d 1c 2c eb 0c RSP: 0018:ffffc90000da7a50 EFLAGS: 00000046 RAX: fffffbfff1d7c4f4 RBX: fffffbfff1d7c4f5 RCX: ffffffff815830c1 RDX: fffffbfff1d7c4f5 RSI: 0000000000000008 RDI: ffffffff8ebe27a0 RBP: fffffbfff1d7c4f4 R08: 0000000000000000 R09: ffffffff8ebe27a7 R10: fffffbfff1d7c4f4 R11: 0000000000000000 R12: ffff888010e509e0 R13: 000000000000002c R14: ffffffff8b363660 R15: 0000000000020000 FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f17c5332028 CR3: 0000000017bf7000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] hlock_class kernel/locking/lockdep.c:198 [inline] check_wait_context kernel/locking/lockdep.c:4506 [inline] __lock_acquire+0x3e1/0x5500 kernel/locking/lockdep.c:4782 lock_acquire kernel/locking/lockdep.c:5437 [inline] lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402 rcu_lock_acquire include/linux/rcupdate.h:259 [inline] rcu_read_lock include/linux/rcupdate.h:648 [inline] gc_worker+0x13a/0xc40 net/netfilter/nf_conntrack_core.c:1371 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296