INFO: task syz-executor.4:16023 can't die for more than 143 seconds. task:syz-executor.4 state:D stack:27888 pid:16023 ppid: 8495 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4312 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5063 schedule+0xcf/0x270 kernel/sched/core.c:5142 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:00007f18ed211c68 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: 00007fff8bd3760f R14: 00007f18ed2129c0 R15: 000000000119c034 INFO: task syz-executor.4:16023 blocked for more than 143 seconds. Not tainted 5.11.0-rc3-next-20210112-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27888 pid:16023 ppid: 8495 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4312 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5063 schedule+0xcf/0x270 kernel/sched/core.c:5142 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:00007f18ed211c68 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: 00007fff8bd3760f R14: 00007f18ed2129c0 R15: 000000000119c034 Showing all locks held in the system: 1 lock held by khungtaskd/1656: #0: ffffffff8b373ea0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8172: #0: ffff88801db6c5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 2 locks held by kworker/1:8/12557: #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: ffffc90002557da8 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1656 Comm: khungtaskd Not tainted 5.11.0-rc3-next-20210112-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: 4893 Comm: systemd-journal Not tainted 5.11.0-rc3-next-20210112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:49 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:121 [inline] RIP: 0010:lock_is_held_type+0x25/0x100 kernel/locking/lockdep.c:5472 Code: 00 00 00 00 00 41 57 41 56 41 89 f6 41 55 41 54 55 48 89 fd 53 48 83 ec 08 e8 f7 cc 5b f8 84 c0 0f 84 b8 00 00 00 9c 8f 04 24 48 c7 c7 20 ac 4b 89 31 db e8 bc 0b 00 00 65 4c 8b 24 25 00 f0 RSP: 0018:ffffc90000effbe8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 1ffffffff1a084db RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff888011c1c18c RBP: ffffffff8b373de0 R08: 0000000000000000 R09: ffffffff8d03f50f R10: fffffbfff1a07ea1 R11: 000000000000003f R12: 0000000000000001 R13: 0000000000000021 R14: 00000000ffffffff R15: dffffc0000000000 FS: 00007f79886b68c0(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7985bc2000 CR3: 0000000011718000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:271 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5b7/0x710 kernel/locking/lockdep.c:5448 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x16/0x50 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:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f7987c46840 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:00007ffddef44298 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: fffffffffffffffe RBX: 00007ffddef445a0 RCX: 00007f7987c46840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 0000559b87073240 RBP: 000000000000000d R08: 000000000000c0ff R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000559b87066040 R14: 00007ffddef44560 R15: 0000559b87071f60