syzbot


INFO: task hung in do_task_dead (4)

Status: auto-obsoleted due to no activity on 2023/06/20 16:27
Subsystems: kernel
[Documentation on labels]
First crash: 627d, last: 627d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in do_task_dead kernel 1 2085d 2085d 0/28 auto-closed as invalid on 2019/09/21 14:08
upstream INFO: task hung in do_task_dead (3) mtd 2 1714d 1716d 0/28 auto-closed as invalid on 2020/06/28 13:10
upstream INFO: task hung in do_task_dead (2) kernel 1 1833d 1833d 0/28 auto-closed as invalid on 2020/03/01 19:02
linux-4.14 INFO: task hung in do_task_dead 1 1580d 1580d 0/1 auto-closed as invalid on 2020/12/09 18:36

Sample crash report:
INFO: task syz-executor.1:32704 blocked for more than 143 seconds.
      Not tainted 6.3.0-rc3-syzkaller-00021-ga1effab7a3a3 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:29032 pid:32704 ppid:5127   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5304 [inline]
 __schedule+0xc91/0x5770 kernel/sched/core.c:6622
 do_task_dead+0xd5/0x100 kernel/sched/core.c:6640
 do_exit+0x1862/0x2960 kernel/exit.c:921
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1019
 get_signal+0x2315/0x25b0 kernel/signal.c:2859
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fdec488c0f9
RSP: 002b:00007fdec55d3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: 0000000000000005 RBX: 00007fdec49ac050 RCX: 00007fdec488c0f9
RDX: 000000000000275a RSI: 0000000020000240 RDI: ffffffffffffff9c
RBP: 00007fdec48e7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc63275cdf R14: 00007fdec55d3300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8c794b70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8c794870 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
 #0: ffffffff8c7956c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6495
2 locks held by getty/4760:
 #0: ffff88814b3a8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:244
 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177
4 locks held by syz-executor.1/32692:
 #0: ffff888036019028 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x29/0x70 net/bluetooth/hci_core.c:552
 #1: ffff888036018078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x306/0x1200 net/bluetooth/hci_sync.c:4837
 #2: ffffffff8e3248a8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1790 [inline]
 #2: ffffffff8e3248a8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xd9/0x260 net/bluetooth/hci_conn.c:2440
 #3: ffffffff8c7a09b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline]
 #3: ffffffff8c7a09b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x64a/0x770 kernel/rcu/tree_exp.h:989
1 lock held by syz-executor.5/4241:
 #0: ffff88803f66d4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_write3+0xe3/0x1e0 sound/core/oss/pcm_oss.c:1255
1 lock held by syz-executor.5/4245:
 #0: ffff88803f66d4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
1 lock held by syz-executor.1/4251:
 #0: ffff888036ec44e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
2 locks held by syz-executor.0/4250:
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1309
 #1: ffff8880a4c54030 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff8880a4c54030 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:534 [inline]
 #1: ffff8880a4c54030 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_file_write_iter+0x1081/0x1740 fs/ext4/file.c:708
1 lock held by syz-executor.0/4252:
 #0: ffff88802a4c14e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_write3+0xe3/0x1e0 sound/core/oss/pcm_oss.c:1255
1 lock held by syz-executor.0/4254:
 #0: ffff88802a4c14e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
1 lock held by syz-executor.0/4255:
 #0: ffff88802a4c14e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: lock_params sound/core/oss/pcm_oss.c:831 [inline]
 #0: ffff88802a4c14e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_set_rate sound/core/oss/pcm_oss.c:1773 [inline]
 #0: ffff88802a4c14e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_ioctl+0xef5/0x3500 sound/core/oss/pcm_oss.c:2638
2 locks held by syz-executor.2/4257:
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1309
 #1: ffff888091a59810 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff888091a59810 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:534 [inline]
 #1: ffff888091a59810 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_file_write_iter+0x1081/0x1740 fs/ext4/file.c:708
1 lock held by syz-executor.2/4262:
 #0: ffff88807e6bd4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
1 lock held by syz-executor.2/4264:
 #0: ffff8880b983c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2f/0x120 kernel/sched/core.c:539
1 lock held by syz-executor.4/4272:
 #0: ffff8880207074e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
1 lock held by syz-executor.5/4276:
 #0: ffff8880207014e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
1 lock held by syz-executor.1/4275:
 #0: ffff8880271064e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
2 locks held by syz-executor.0/4274:
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 #0: ffff88802a3a2460 (sb_writers#4){.+.+}-{0:0}, at: __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1309
 #1: ffff88809a88a218 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff88809a88a218 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:534 [inline]
 #1: ffff88809a88a218 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_file_write_iter+0x1081/0x1740 fs/ext4/file.c:708
1 lock held by syz-executor.0/4283:
 #0: ffff88807e60d4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
1 lock held by syz-executor.3/4282:
 #0: ffff88803b7ee4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_sync+0x305/0x810 sound/core/oss/pcm_oss.c:1676
1 lock held by syz-executor.3/4284:
 #0: ffff88803b7ee4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: lock_params sound/core/oss/pcm_oss.c:831 [inline]
 #0: ffff88803b7ee4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_set_rate sound/core/oss/pcm_oss.c:1773 [inline]
 #0: ffff88803b7ee4e0 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_ioctl+0xef5/0x3500 sound/core/oss/pcm_oss.c:2638

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.3.0-rc3-syzkaller-00021-ga1effab7a3a3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xe16/0x1090 kernel/hung_task.c:379
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 22288 Comm: kworker/u4:9 Not tainted 6.3.0-rc3-syzkaller-00021-ga1effab7a3a3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:774 [inline]
RIP: 0010:batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline]
RIP: 0010:batadv_iv_ogm_schedule_buff+0xb01/0x1520 net/batman-adv/bat_iv_ogm.c:825
Code: 8b c6 05 0f 04 99 04 01 e8 ec a4 9a f7 e9 68 fc ff ff e8 92 aa b9 f7 e8 2d e7 a2 f7 31 ff 89 c5 89 c6 e8 92 a6 b9 f7 40 84 ed <0f> 85 e2 fa ff ff e8 74 aa b9 f7 e8 3f 9d 38 00 31 ff 89 c5 89 c6
RSP: 0018:ffffc9000392fb90 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff888037f4d258 RCX: ffffffff89c93a7e
RDX: ffff88803bab1d40 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 1ffffffff18f4061 R12: ffff8880396378a4
R13: dffffc0000000000 R14: ffff888038044c80 R15: 000000000000024b
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe759eabd38 CR3: 000000001ff43000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:868 [inline]
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:861 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x333/0x960 net/batman-adv/bat_iv_ogm.c:1712
 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390
 worker_thread+0x669/0x1090 kernel/workqueue.c:2537
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/22 16:25 upstream a1effab7a3a3 d846e076 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in do_task_dead
* Struck through repros no longer work on HEAD.