INFO: task kworker/u4:1:21 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:1 D24696 21 2 0x80004000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 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+0x16a/0x270 kernel/sched/completion.c:138 __synchronize_srcu+0x1a7/0x260 kernel/rcu/srcutree.c:922 fsnotify_connector_destroy_workfn+0x49/0xa0 fs/notify/mark.c:164 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/u4:2:43 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:2 D24792 43 2 0x80004000 Workqueue: events_unbound fsnotify_mark_destroy_workfn Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 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+0x16a/0x270 kernel/sched/completion.c:138 __synchronize_srcu+0x1a7/0x260 kernel/rcu/srcutree.c:922 fsnotify_mark_destroy_workfn+0xfd/0x330 fs/notify/mark.c:832 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.2:25409 can't die for more than 144 seconds. syz-executor.2 D26288 25409 7276 0x00004004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 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+0x16a/0x270 kernel/sched/completion.c:138 __flush_work+0x4fd/0xa80 kernel/workqueue.c:3045 __cancel_work_timer+0x3a2/0x500 kernel/workqueue.c:3132 p9_conn_destroy net/9p/trans_fd.c:863 [inline] p9_fd_close+0x29c/0x520 net/9p/trans_fd.c:898 p9_client_create+0x99b/0x1440 net/9p/client.c:1069 v9fs_session_init+0x1e7/0x18c0 fs/9p/v9fs.c:406 v9fs_mount+0x79/0x970 fs/9p/vfs_super.c:124 legacy_get_tree+0x105/0x220 fs/fs_context.c:622 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2813 [inline] do_mount+0x1306/0x1b30 fs/namespace.c:3138 __do_sys_mount fs/namespace.c:3347 [inline] __se_sys_mount fs/namespace.c:3324 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3324 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: Bad RIP value. RSP: 002b:00007f281784dc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00000000004f62c0 RCX: 000000000045ca29 RDX: 0000000020000080 RSI: 0000000020000140 RDI: 0000000000000000 RBP: 000000000078bf00 R08: 0000000020000100 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000752 R14: 00000000004ca315 R15: 00007f281784e6d4 INFO: task syz-executor.2:25409 blocked for more than 144 seconds. Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D26288 25409 7276 0x00004004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 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+0x16a/0x270 kernel/sched/completion.c:138 __flush_work+0x4fd/0xa80 kernel/workqueue.c:3045 __cancel_work_timer+0x3a2/0x500 kernel/workqueue.c:3132 p9_conn_destroy net/9p/trans_fd.c:863 [inline] p9_fd_close+0x29c/0x520 net/9p/trans_fd.c:898 p9_client_create+0x99b/0x1440 net/9p/client.c:1069 v9fs_session_init+0x1e7/0x18c0 fs/9p/v9fs.c:406 v9fs_mount+0x79/0x970 fs/9p/vfs_super.c:124 legacy_get_tree+0x105/0x220 fs/fs_context.c:622 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2813 [inline] do_mount+0x1306/0x1b30 fs/namespace.c:3138 __do_sys_mount fs/namespace.c:3347 [inline] __se_sys_mount fs/namespace.c:3324 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3324 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: Bad RIP value. RSP: 002b:00007f281784dc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00000000004f62c0 RCX: 000000000045ca29 RDX: 0000000020000080 RSI: 0000000020000140 RDI: 0000000000000000 RBP: 000000000078bf00 R08: 0000000020000100 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000752 R14: 00000000004ca315 R15: 00007f281784e6d4 Showing all locks held in the system: 2 locks held by kworker/u4:1/21: #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239 #1: ffffc90000dd7dc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 2 locks held by kworker/u4:2/43: #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880aa034138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239 #1: ffffc90000f07dc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 1 lock held by khungtaskd/1163: #0: ffffffff899befc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 2 locks held by kworker/0:2/2713: 1 lock held by in:imklog/6751: #0: ffff8880a7133e30 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by agetty/6979: #0: ffff8880a6d4e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000fc02e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x220/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by agetty/6982: #0: ffff88809f200098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000fb02e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x220/0x1b30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1163 Comm: khungtaskd Not tainted 5.7.0-rc1-next-20200415-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:249 [inline] watchdog+0xde3/0x14e0 kernel/hung_task.c:333 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2713 Comm: kworker/0:2 Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events p9_read_work RIP: 0010:write_comp_data+0x2e/0x80 kernel/kcov.c:218 Code: 25 00 1f 02 00 65 8b 05 c8 e9 8e 7e a9 00 01 1f 00 74 10 f6 c4 01 74 5c 41 8b 80 04 14 00 00 85 c0 74 51 41 8b 80 e0 13 00 00 <83> f8 03 75 45 49 8b 80 e8 13 00 00 45 8b 80 e4 13 00 00 4c 8b 08 RSP: 0018:ffffc90008f67af0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff860207e1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff888215178000 R08: ffff88809ff4a080 R09: ffffed1012320c7c R10: ffffc90008f67b28 R11: ffffed1012320c7b R12: 0000000000000000 R13: ffff888091906000 R14: ffff888091906370 R15: 0000000000000007 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f450499b000 CR3: 0000000094994000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: snd_pcm_oss_make_ready_locked+0x91/0x130 sound/core/oss/pcm_oss.c:1170 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1494 [inline] snd_pcm_oss_read+0x350/0x6f0 sound/core/oss/pcm_oss.c:2742 __vfs_read+0x76/0x100 fs/read_write.c:426 vfs_read+0x1f0/0x420 fs/read_write.c:462 kernel_read+0xaf/0x120 fs/read_write.c:441 p9_fd_read net/9p/trans_fd.c:263 [inline] p9_read_work+0x2aa/0xfa0 net/9p/trans_fd.c:298 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352