syzbot


INFO: task hung in snd_timer_open

Status: auto-closed as invalid on 2019/02/22 14:33
First crash: 2264d, last: 2264d

Sample crash report:
INFO: task syz-executor5:10231 blocked for more than 120 seconds.
      Not tainted 4.9.80-g550c01d #29
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D28480 10231   3901 0x00000004
 ffff8801adc36000 ffff8801cb502a00 ffff8801cb502a00 ffff8801c3a74800
 ffff8801db321b98 ffff8801adc4f388 ffffffff838a23db 0000000000000001
 0000000000000007 00ff8801adc36000 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a397f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838a4303>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3583
 [<ffffffff838a9912>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838a9912>] mutex_lock_nested+0x312/0x870 kernel/locking/mutex.c:621
 [<ffffffff82dab2c9>] snd_timer_open+0x449/0xde0 sound/core/timer.c:268
 [<ffffffff82e1fbff>] snd_seq_timer_open+0x22f/0x5b0 sound/core/seq/seq_timer.c:287
 [<ffffffff82e1901f>] queue_use+0x8f/0x1e0 sound/core/seq/seq_queue.c:524
 [<ffffffff82e19c1d>] snd_seq_queue_alloc+0x29d/0x490 sound/core/seq/seq_queue.c:199
 [<ffffffff82e0e26d>] snd_seq_ioctl_create_queue+0xad/0x2f0 sound/core/seq/seq_clientmgr.c:1512
 [<ffffffff82e0bba2>] snd_seq_kernel_client_ctl+0x122/0x160 sound/core/seq/seq_clientmgr.c:2352
 [<ffffffff82e285b8>] alloc_seq_queue.isra.1+0xc8/0x160 sound/core/seq/oss/seq_oss_init.c:370
 [<ffffffff82e28c73>] snd_seq_oss_open+0x223/0x8c0 sound/core/seq/oss/seq_oss_init.c:228
 [<ffffffff82e27e0a>] odev_open+0x6a/0x90 sound/core/seq/oss/seq_oss.c:138
 [<ffffffff82d85eb1>] soundcore_open+0x321/0x630 sound/sound_core.c:639
 [<ffffffff8157c0ab>] chrdev_open+0x22b/0x4c0 fs/char_dev.c:392
 [<ffffffff81566ff7>] do_dentry_open+0x607/0xc60 fs/open.c:766
 [<ffffffff8156aaa5>] vfs_open+0x105/0x220 fs/open.c:879
 [<ffffffff815a156c>] do_last fs/namei.c:3408 [inline]
 [<ffffffff815a156c>] path_openat+0x5ac/0x2910 fs/namei.c:3531
 [<ffffffff815a70c7>] do_filp_open+0x197/0x290 fs/namei.c:3566
 [<ffffffff8156b596>] do_sys_open+0x366/0x620 fs/open.c:1072
 [<ffffffff8156b8c0>] SYSC_openat fs/open.c:1099 [inline]
 [<ffffffff8156b8c0>] SyS_openat+0x30/0x40 fs/open.c:1093
 [<ffffffff838b346e>] entry_SYSCALL_64_fastpath+0x29/0xe8

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372ed5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372ed5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81237fe0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
2 locks held by getty/3784:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b1652>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff82009fa4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
2 locks held by syz-executor5/10231:
 #0:  (register_mutex#4){+.+.+.}, at: [<ffffffff82e27dff>] odev_open+0x5f/0x90 sound/core/seq/oss/seq_oss.c:137
 #1:  (register_mutex){+.+.+.}, at: [<ffffffff82dab2c9>] snd_timer_open+0x449/0xde0 sound/core/timer.c:268
1 lock held by syz-executor3/10417:
 #0:  (register_mutex#4){+.+.+.}, at: [<ffffffff82e27dff>] odev_open+0x5f/0x90 sound/core/seq/oss/seq_oss.c:137
2 locks held by syz-executor3/10418:
 #0:  (&tu->ioctl_lock){+.+.+.}, at: [<ffffffff82daed33>] snd_timer_user_ioctl+0x53/0xb0 sound/core/timer.c:1943
 #1:  (register_mutex){+.+.+.}, at: [<ffffffff82daaf2f>] snd_timer_open+0xaf/0xde0 sound/core/timer.c:251
1 lock held by syz-executor3/10419:
 #0:  (&tu->ioctl_lock){+.+.+.}, at: [<ffffffff82daed33>] snd_timer_user_ioctl+0x53/0xb0 sound/core/timer.c:1943
1 lock held by syz-executor3/10420:
 #0:  (register_mutex#4){+.+.+.}, at: [<ffffffff82e27dff>] odev_open+0x5f/0x90 sound/core/seq/oss/seq_oss.c:137
2 locks held by syz-executor3/10421:
 #0:  (&tu->ioctl_lock){+.+.+.}, at: [<ffffffff82daed33>] snd_timer_user_ioctl+0x53/0xb0 sound/core/timer.c:1943
 #1:  (register_mutex){+.+.+.}, at: [<ffffffff82daaf2f>] snd_timer_open+0xaf/0xde0 sound/core/timer.c:251
1 lock held by syz-executor3/10422:
 #0:  (&tu->ioctl_lock){+.+.+.}, at: [<ffffffff82daed33>] snd_timer_user_ioctl+0x53/0xb0 sound/core/timer.c:1943

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 514 Comm: khungtaskd Not tainted 4.9.80-g550c01d #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d85b7d00 ffffffff81d94b69 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810bac60 ffff8801d85b7d38
 ffffffff81d9fc8d 0000000000000000 0000000000000000 ffff8801adc5e418
Call Trace:
 [<ffffffff81d94b69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d94b69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9fc8d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9fdc7>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bad54>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813734a0>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813734a0>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813734a0>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813734a0>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119a73d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b37dc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:477
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10227 Comm: syz-executor3 Not tainted 4.9.80-g550c01d #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cba36000 task.stack: ffff8801adc80000
RIP: 0010:[<ffffffff81dc3113>] c [<ffffffff81dc3113>] rep_nop arch/x86/include/asm/processor.h:584 [inline]
RIP: 0010:[<ffffffff81dc3113>] c [<ffffffff81dc3113>] delay_tsc+0x33/0xc0 arch/x86/lib/delay.c:66
RSP: 0018:ffff8801adc87940  EFLAGS: 00000286
RAX: 0000000080000000 RBX: 00000084b511da06 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff83c18780 RDI: ffffffff858fe7c0
RBP: ffff8801adc87960 R08: 1ffff10039746d1f R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00000084b511a875
R13: 00000000000059d9 R14: 0000000000000001 R15: ffffffff82da7a10
FS:  00007f70675ff700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004d6d98 CR3: 00000001b4776000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffed003b004c2ac ffff8801d8026140c ffff8801d8026140c ffff8801cfe21cb0c
 ffff8801adc87970c ffffffff81dc306bc ffff8801adc879c8c ffffffff82da7497c
 ffff8801d8026150c ffff8801c23d7c10c ffff8801cfe21cb0c ffff8801cfe21b80c
Call Trace:
 [<ffffffff81dc306b>] __delay arch/x86/lib/delay.c:160 [inline]
 [<ffffffff81dc306b>] __const_udelay+0x2b/0x30 arch/x86/lib/delay.c:174
 [<ffffffff82da7497>] snd_timer_close+0xf7/0x670 sound/core/timer.c:345
 [<ffffffff82da7aa7>] snd_timer_user_release+0x97/0x130 sound/core/timer.c:1365
 [<ffffffff8157568c>] __fput+0x28c/0x6e0 fs/file_table.c:208
 [<ffffffff81575b65>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff811957d5>] task_work_run+0x115/0x190 kernel/task_work.c:116
 [<ffffffff8113c277>] exit_task_work include/linux/task_work.h:21 [inline]
 [<ffffffff8113c277>] do_exit+0x7e7/0x2a40 kernel/exit.c:833
 [<ffffffff81142988>] do_group_exit+0x108/0x320 kernel/exit.c:937
 [<ffffffff811657e4>] get_signal+0x4d4/0x14e0 kernel/signal.c:2317
 [<ffffffff81052c87>] do_signal+0x87/0x1a00 arch/x86/kernel/signal.c:807
 [<ffffffff81003a31>] exit_to_usermode_loop+0xe1/0x120 arch/x86/entry/common.c:156
 [<ffffffff81006340>] prepare_exit_to_usermode arch/x86/entry/common.c:190 [inline]
 [<ffffffff81006340>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259
 [<ffffffff838b352b>] entry_SYSCALL_64_fastpath+0xe6/0xe8
Code: c49 c89 cfd cbf c01 c00 c00 c00 c41 c54 c53 ce8 c48 c79 c3f cff ce8 c73 c90 c03 c00 c41 c89 cc6 c0f cae ce8 c0f c31 c48 cc1 ce2 c20 c48 c09 cc2 c49 c89 cd4 ceb c16 cf3 c90 c<bf> c01 c00 c00 c00 ce8 c23 c79 c3f cff ce8 c4e c90 c03 c00 c44 c39 cf0 c75 c36 c0f c

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/02/06 23:04 https://android.googlesource.com/kernel/common android-4.9 550c01d0e051 66c15deb .config console log report ci-android-49-kasan-gce
* Struck through repros no longer work on HEAD.