syzbot


INFO: task hung in deactivate_super (3)

Status: upstream: reported on 2024/05/27 12:00
Reported-by: syzbot+4ae63a93dbe1440d6ba3@syzkaller.appspotmail.com
First crash: 141d, last: 6d12h
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in deactivate_super 3 2285d 2303d 0/3 auto-closed as invalid on 2019/02/22 12:34
linux-6.1 INFO: task hung in deactivate_super 4 423d 473d 0/3 auto-obsoleted due to no activity on 2023/11/26 12:17
linux-4.14 INFO: task hung in deactivate_super 1 1996d 1995d 0/1 auto-closed as invalid on 2019/10/25 08:42
upstream INFO: task hung in deactivate_super exfat 36 2107d 2210d 0/28 closed as dup on 2018/10/27 13:17
upstream INFO: task hung in deactivate_super (2) reiserfs C inconclusive done 121 226d 565d 25/28 fixed on 2024/04/08 19:23
upstream INFO: task hung in deactivate_super (3) jfs 63 7d21h 96d 0/28 upstream: reported on 2024/07/11 01:05
linux-5.15 INFO: task hung in deactivate_super 4 420d 509d 0/3 auto-obsoleted due to no activity on 2023/11/29 20:11
linux-6.1 INFO: task hung in deactivate_super (2) 1 244d 244d 0/3 auto-obsoleted due to no activity on 2024/05/24 05:27
linux-4.19 INFO: task hung in deactivate_super 4 597d 699d 0/1 upstream: reported on 2022/11/16 10:48

Sample crash report:
INFO: task syz-executor:3647 blocked for more than 143 seconds.
      Not tainted 6.1.112-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:20536 pid:3647  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 rwsem_down_write_slowpath+0xea1/0x14b0 kernel/locking/rwsem.c:1189
 deactivate_super+0xa9/0xe0 fs/super.c:362
 cleanup_mnt+0x490/0x520 fs/namespace.c:1186
 task_work_run+0x246/0x300 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f52c9b7f327
RSP: 002b:00007ffcc8652638 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f52c9bf0134 RCX: 00007f52c9b7f327
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcc86526f0
RBP: 00007ffcc86526f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcc8653770
R13: 00007f52c9bf0134 R14: 000000000001d0e0 R15: 00007ffcc86537b0
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32b1d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32b9d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by getty/3395:
 #0: ffff88802e08f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/3647:
 #0: ffff888059ae80e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
2 locks held by kworker/1:4/3686:
 #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc9000488fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
3 locks held by kworker/1:5/3688:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900048afd20 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #2: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
4 locks held by kworker/u4:7/3740:
 #0: ffff888017e1e938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90004a8fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e4ee490 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:566
 #3: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #3: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
2 locks held by ext4lazyinit/4095:
1 lock held by syz.0.102/4584:
 #0: ffff888059ae80e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.4.193/4694:
 #0: ffff888059ae80e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.1.210/4855:
 #0: ffff888059ae80e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.0.224/4985:
 #0: ffff888059ae80e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
3 locks held by syz-executor/5063:
 #0: ffff8880628290b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff8880628290b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2710
 #1: ffff888062828078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0x1020 net/bluetooth/hci_sync.c:5053
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1800 [inline]
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2446
3 locks held by syz-executor/5078:
 #0: ffff8880510f50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff8880510f50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2710
 #1: ffff8880510f4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0x1020 net/bluetooth/hci_sync.c:5053
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1800 [inline]
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2446
1 lock held by syz.3.244/5085:
 #0: ffff888059ae80e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
3 locks held by syz-executor/5189:
 #0: ffff8880733750b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff8880733750b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2710
 #1: ffff888073374078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0x1020 net/bluetooth/hci_sync.c:5053
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1800 [inline]
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2446
1 lock held by syz.1.263/5224:
 #0: ffff888059ae80e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
3 locks held by syz-executor/5323:
 #0: ffff88807b04d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff88807b04d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2710
 #1: ffff88807b04c078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0x1020 net/bluetooth/hci_sync.c:5053
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1800 [inline]
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2446
3 locks held by syz.4.273/5337:
 #0: ffff88802bbad0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff88802bbad0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2710
 #1: ffff88802bbac078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0x1020 net/bluetooth/hci_sync.c:5053
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1800 [inline]
 #2: ffffffff8e651cc8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2446

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65
Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01
RSP: 0018:ffffc900001b74b8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffc900001b7780 RCX: 0000000000000000
RDX: 0000000000000020 RSI: 0000000000000000 RDI: ffffc900001b7630
RBP: ffffc900001b76c0 R08: dffffc0000000000 R09: ffffc900001b7610
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc900001b7780
R13: dffffc0000000000 R14: ffffc900001b7610 R15: ffff888077c70030
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3131dff8 CR3: 000000000d08e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 ip6t_do_table+0xd4/0x1830 net/ipv6/netfilter/ip6_tables.c:263
 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
 nf_hook_slow+0xae/0x1e0 net/netfilter/core.c:614
 nf_hook include/linux/netfilter.h:257 [inline]
 NF_HOOK+0x29a/0x450 include/linux/netfilter.h:300
 __netif_receive_skb_one_core net/core/dev.c:5528 [inline]
 __netif_receive_skb+0x1c6/0x530 net/core/dev.c:5642
 process_backlog+0x381/0x760 net/core/dev.c:5970
 __napi_poll+0xc7/0x470 net/core/dev.c:6537
 napi_poll net/core/dev.c:6604 [inline]
 net_rx_action+0x70f/0xeb0 net/core/dev.c:6718
 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571
 run_ksoftirqd+0xc6/0x120 kernel/softirq.c:938
 smpboot_thread_fn+0x52c/0xa30 kernel/smpboot.c:164
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/08 23:22 linux-6.1.y aa4cd140bba5 402f1df0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in deactivate_super
2024/09/26 13:00 linux-6.1.y e526b12bf916 0d19f247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in deactivate_super
2024/09/12 07:27 linux-6.1.y 5ca5b389fddf d94c83d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in deactivate_super
2024/08/14 16:45 linux-6.1.y 117ac406ba90 e6b88e20 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in deactivate_super
2024/07/30 11:12 linux-6.1.y c1cec4dad96b 5187fc86 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in deactivate_super
2024/05/27 12:00 linux-6.1.y 88690811da69 761766e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in deactivate_super
* Struck through repros no longer work on HEAD.