syzbot

INFO: task syz-executor.2:27333 blocked for more than 143 seconds.
      Not tainted 5.3.0-rc4 #100
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D25520 27333  10480 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x755/0x1580 kernel/sched/core.c:3880
 schedule+0xa8/0x270 kernel/sched/core.c:3944
 rwsem_down_read_slowpath+0x4cc/0xfb0 kernel/locking/rwsem.c:1090
 __down_read kernel/locking/rwsem.c:1320 [inline]
 down_read_nested+0x1f8/0x3f0 kernel/locking/rwsem.c:1573
 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:683 [inline]
 snd_seq_deliver_event+0x2b0/0x8d0 sound/core/seq/seq_clientmgr.c:828
 snd_seq_kernel_client_dispatch+0x155/0x180 sound/core/seq/seq_clientmgr.c:2324
 dummy_input sound/core/seq/seq_dummy.c:90 [inline]
 dummy_input+0x272/0x360 sound/core/seq/seq_dummy.c:74
 snd_seq_deliver_single_event.constprop.0+0x459/0x890 sound/core/seq/seq_clientmgr.c:638
 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:693 [inline]
 snd_seq_deliver_event+0x341/0x8d0 sound/core/seq/seq_clientmgr.c:828
 snd_seq_kernel_client_dispatch+0x155/0x180 sound/core/seq/seq_clientmgr.c:2324
 dummy_input sound/core/seq/seq_dummy.c:90 [inline]
 dummy_input+0x272/0x360 sound/core/seq/seq_dummy.c:74
 snd_seq_deliver_single_event.constprop.0+0x459/0x890 sound/core/seq/seq_clientmgr.c:638
 snd_seq_deliver_event+0x57f/0x8d0 sound/core/seq/seq_clientmgr.c:839
 snd_seq_kernel_client_dispatch+0x155/0x180 sound/core/seq/seq_clientmgr.c:2324
 snd_seq_oss_dispatch sound/core/seq/oss/seq_oss_device.h:138 [inline]
 snd_seq_oss_midi_reset+0x478/0x580 sound/core/seq/oss/seq_oss_midi.c:477
 snd_seq_oss_synth_reset+0x412/0x8f0 sound/core/seq/oss/seq_oss_synth.c:404
 snd_seq_oss_reset+0x79/0x2b0 sound/core/seq/oss/seq_oss_init.c:435
 snd_seq_oss_release+0x74/0x150 sound/core/seq/oss/seq_oss_init.c:412
 odev_release+0x54/0x80 sound/core/seq/oss/seq_oss.c:140
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: 24 60 48 8b 42 08 48 8b 4a 10 48 8b 5a 18 48 8b 72 20 48 8b 7a 28 48 8b 3f 4c 8b 42 30 48 8b 52 38 48 85 d2 76 62 48 89 44 24 <58> 4c 89 44 24 28 48 89 0c 24 48 89 5c 24 08 48 c7 44 24 10 00 00
RSP: 002b:00007f05c1d3ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffea RBX: 0000000000000004 RCX: 0000000000459829
RDX: 5af9eba5b614ee0b RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f05c1d3b6d4
R13: 00000000004c641d R14: 00000000004db2f0 R15: 00000000ffffffff
INFO: task syz-executor.2:27563 blocked for more than 143 seconds.
      Not tainted 5.3.0-rc4 #100
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28768 27563  10480 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x755/0x1580 kernel/sched/core.c:3880
 schedule+0xa8/0x270 kernel/sched/core.c:3944
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4003
 __mutex_lock_common kernel/locking/mutex.c:1007 [inline]
 __mutex_lock+0x7b0/0x13c0 kernel/locking/mutex.c:1077
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1092
 odev_open+0x5f/0x90 sound/core/seq/oss/seq_oss.c:124
 soundcore_open+0x453/0x610 sound/sound_core.c:593
 chrdev_open+0x245/0x6b0 fs/char_dev.c:414
 do_dentry_open+0x4df/0x1250 fs/open.c:797
 vfs_open+0xa0/0xd0 fs/open.c:906
 do_last fs/namei.c:3416 [inline]
 path_openat+0x10e9/0x4630 fs/namei.c:3533
 do_filp_open+0x1a1/0x280 fs/namei.c:3563
 do_sys_open+0x3fe/0x5d0 fs/open.c:1089
 __do_sys_openat fs/open.c:1116 [inline]
 __se_sys_openat fs/open.c:1110 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1110
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: Bad RIP value.
RSP: 002b:00007f05c1d19c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459829
RDX: 5af9eba5b614ee0b RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f05c1d1a6d4
R13: 00000000004c641d R14: 00000000004db2f0 R15: 00000000ffffffff
INFO: task syz-executor.0:27332 blocked for more than 144 seconds.
      Not tainted 5.3.0-rc4 #100
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28784 27332  10475 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x755/0x1580 kernel/sched/core.c:3880
 schedule+0xa8/0x270 kernel/sched/core.c:3944
 rwsem_down_write_slowpath+0x708/0xf60 kernel/locking/rwsem.c:1214
 __down_write kernel/locking/rwsem.c:1365 [inline]
 down_write+0x13c/0x150 kernel/locking/rwsem.c:1501
 delete_and_unsubscribe_port+0x61/0x4f0 sound/core/seq/seq_ports.c:528
 snd_seq_port_connect+0x427/0x510 sound/core/seq/seq_ports.c:578
 snd_seq_ioctl_subscribe_port+0x1e5/0x310 sound/core/seq/seq_clientmgr.c:1484
 snd_seq_ioctl+0x21f/0x400 sound/core/seq/seq_clientmgr.c:2158
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: Bad RIP value.
RSP: 002b:00007f55c3924c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829
RDX: 0000000020000140 RSI: 0000000040505330 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f55c39256d4
R13: 00000000004cdab0 R14: 00000000004d7ac8 R15: 00000000ffffffff
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 1049 Comm: khungtaskd Not tainted 5.3.0-rc4 #100
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+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0x9d0/0xef0 kernel/hung_task.c:289
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60