INFO: task syz-executor.3:10690 can't die for more than 143 seconds. task:syz-executor.3 state:D stack:28112 pid:10690 ppid: 8501 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4373 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5124 schedule+0xcf/0x270 kernel/sched/core.c:5203 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1868 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_create+0x95a/0x1110 net/9p/client.c:1071 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:406 v9fs_mount+0x79/0x9c0 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:2889 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3220 do_mount fs/namespace.c:3233 [inline] __do_sys_mount fs/namespace.c:3441 [inline] __se_sys_mount fs/namespace.c:3418 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3418 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 RSP: 002b:00007f6ab70cdc68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000119c1c8 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c184 R13: 00007ffce3d4f92f R14: 00007f6ab70ce9c0 R15: 000000000119c184 INFO: task syz-executor.3:10690 blocked for more than 143 seconds. Not tainted 5.11.0-rc3-next-20210113-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:28112 pid:10690 ppid: 8501 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4373 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5124 schedule+0xcf/0x270 kernel/sched/core.c:5203 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1868 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_create+0x95a/0x1110 net/9p/client.c:1071 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:406 v9fs_mount+0x79/0x9c0 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:2889 [inline] path_mount+0x12ae/0x1e70 fs/namespace.c:3220 do_mount fs/namespace.c:3233 [inline] __do_sys_mount fs/namespace.c:3441 [inline] __se_sys_mount fs/namespace.c:3418 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3418 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 RSP: 002b:00007f6ab70cdc68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000000000000 RBP: 000000000119c1c8 R08: 0000000020000580 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c184 R13: 00007ffce3d4f92f R14: 00007f6ab70ce9c0 R15: 000000000119c184 Showing all locks held in the system: 1 lock held by khungtaskd/1663: #0: ffffffff8b374160 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 3 locks held by kworker/u4:5/4494: 1 lock held by in:imklog/8192: #0: ffff8880122a7270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 2 locks held by kworker/1:3/9051: #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: ffffc90002817da8 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1663 Comm: khungtaskd Not tainted 5.11.0-rc3-next-20210113-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4888 Comm: systemd-journal Not tainted 5.11.0-rc3-next-20210113-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:trace_hardirqs_on+0x69/0x1c0 kernel/trace/trace_preemptirq.c:44 Code: fa ff 65 c7 05 b4 fd 89 7e 00 00 00 00 e8 bf 2a fa ff 48 8b 7c 24 18 e8 f5 85 df ff 48 8b 7c 24 18 5b 5d 41 5c e9 97 20 83 07 a2 2a fa ff 48 8b 6c 24 18 0f 1f 44 00 00 e8 93 2a fa ff eb bd RSP: 0018:ffffc900018bfce0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff888025ec0000 RDI: 0000000000000003 RBP: ffffffff8f30c4a8 R08: 0000000000000000 R09: ffffffff8f30c4ab R10: ffffffff8178fd98 R11: 000000000000003f R12: 0000000000000008 R13: 0000000000000008 R14: dead000000000100 R15: dffffc0000000000 FS: 00007fa7da32c8c0(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa7d774d020 CR3: 00000000256c6000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x42/0x50 kernel/locking/spinlock.c:191 __debug_check_no_obj_freed lib/debugobjects.c:997 [inline] debug_check_no_obj_freed+0x20c/0x420 lib/debugobjects.c:1018 slab_free_hook mm/slub.c:1540 [inline] slab_free_freelist_hook+0x12b/0x1d0 mm/slub.c:1586 slab_free mm/slub.c:3157 [inline] kmem_cache_free+0x8b/0x740 mm/slub.c:3173 security_file_free+0xa4/0xd0 security/security.c:1476 file_free fs/file_table.c:55 [inline] __fput+0x3d5/0x920 fs/file_table.c:298 task_work_run+0xdd/0x190 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:177 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:301 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:312 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fa7d98bc840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007ffe941d0f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: fffffffffffffffe RBX: 00007ffe941d1220 RCX: 00007fa7d98bc840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005610271e3580 RBP: 000000000000000d R08: 000000000000c0c1 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 00005610271df040 R14: 00007ffe941d11e0 R15: 00005610271ed110