syzbot


INFO: task hung in __pfx_do_exit

Status: auto-obsoleted due to no activity on 2024/11/24 06:16
Subsystems: serial
[Documentation on labels]
First crash: 122d, last: 122d

Sample crash report:
INFO: task syz.2.214:7647 blocked for more than 143 seconds.
      Not tainted 6.11.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.214       state:D stack:24096 pid:7647  tgid:7646  ppid:7106   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 __pfx_do_exit+0x10/0x10
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e738320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626
2 locks held by kworker/u8:9/2567:
2 locks held by getty/4966:
 #0: ffff88802af630a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211
5 locks held by kworker/u9:2/5220:
 #0: ffff888053cab948 ((wq_completion)hci9){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888053cab948 ((wq_completion)hci9){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90003947d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90003947d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff888022bd4d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:327
 #3: ffff888022bd4078 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x1ea/0xde0 net/bluetooth/hci_sync.c:5526
 #4: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline]
 #4: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958
5 locks held by kworker/u9:4/5228:
 #0: ffff8880224d2948 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff8880224d2948 ((wq_completion)hci4){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc900039b7d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc900039b7d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff8880209b0d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:327
 #3: ffff8880209b0078 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x1ea/0xde0 net/bluetooth/hci_sync.c:5526
 #4: ffffffff8fbde068 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1962 [inline]
 #4: ffffffff8fbde068 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_failed+0x185/0x340 net/bluetooth/hci_conn.c:1265
3 locks held by kworker/0:3/5266:
 #0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000400fd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000400fd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline]
 #2: ffffffff8e73d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958
1 lock held by syz.3.148/7342:
2 locks held by syz-executor/7582:
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505
 #1: ffffffff8eb47868 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xb2/0x530 fs/jfs/jfs_logmgr.c:1444
3 locks held by syz.2.214/7647:
 #0: ffff888058108d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
 #0: ffff888058108d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2692
 #1: ffff888058108078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5145
 #2: ffffffff8fbde068 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1977 [inline]
 #2: ffffffff8fbde068 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592
1 lock held by syz.0.232/7817:
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
1 lock held by syz.4.241/7900:
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
1 lock held by syz.2.277/8053:
1 lock held by syz.1.310/8476:
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88801ce920e0 (&type->s_umount_key#77){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
1 lock held by syz-executor/8612:
4 locks held by kworker/u8:6/8615:
3 locks held by syz.0.464/9329:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 46 Comm: kworker/1:1 Not tainted 6.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: events free_obj_work
RIP: 0010:__sanitizer_cov_trace_switch+0x98/0x120 kernel/kcov.c:350
Code: 00 41 b8 05 00 00 00 4d 85 d2 0f 84 8b 00 00 00 4c 8b 4c 24 20 65 4c 8b 1c 25 c0 d6 03 00 31 d2 eb 08 48 ff c2 49 39 d2 74 71 <4c> 8b 74 d6 10 65 8b 05 24 43 70 7e 25 00 01 ff 00 74 11 3d 00 01
RSP: 0018:ffffc90000b67540 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88801c681e00
RDX: 0000000000000004 RSI: ffffffff8e5a3da0 RDI: 0000000000000005
RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff81412f0e
R10: 0000000000000008 R11: ffff88801c681e00 R12: ffffffff900f2d94
R13: dffffc0000000000 R14: 0000000000000005 R15: 1ffff9200016cec8
FS:  0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f28bbce52d8 CR3: 000000007dd9e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 unwind_next_frame+0x7be/0x2a00 arch/x86/kernel/unwind_orc.c:515
 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kmem_cache_free+0x145/0x350 mm/slub.c:4548
 free_obj_work+0x4ff/0x6d0 lib/debugobjects.c:332
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd10 kernel/workqueue.c:3389
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/26 06:14 upstream 5be63fc19fca d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in __pfx_do_exit
* Struck through repros no longer work on HEAD.