[syzbot] [kernel?] INFO: task hung in worker_attach_to_pool (2)

[syzbot <syzbot+8b08b50984ccfdd38ce2@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    87d6aab2389e Merge tag 'for_linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17e41780580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7cd9e7e4a8a0a15b
dashboard link: https://syzkaller.appspot.com/bug?extid=8b08b50984ccfdd38ce2
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2a469cdf081f/disk-87d6aab2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/782fd2d1cfc7/vmlinux-87d6aab2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/450f9a610cbe/bzImage-87d6aab2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8b08b50984ccfdd38ce2@syzkaller.appspotmail.com

INFO: task kworker/R-wg-cr:9362 blocked for more than 159 seconds.
      Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/R-wg-cr state:D stack:27704 pid:9362  tgid:9362  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5315 [inline]
 __schedule+0x1895/0x4b30 kernel/sched/core.c:6675
 __schedule_loop kernel/sched/core.c:6752 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6767
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 worker_attach_to_pool+0x31/0x390 kernel/workqueue.c:2669
 rescuer_thread+0x3ed/0x10a0 kernel/workqueue.c:3471
 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>
INFO: task kworker/R-wg-cr:11253 blocked for more than 160 seconds.
      Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/R-wg-cr state:D stack:28720 pid:11253 tgid:11253 ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5315 [inline]
 __schedule+0x1895/0x4b30 kernel/sched/core.c:6675
 __schedule_loop kernel/sched/core.c:6752 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6767
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 worker_detach_from_pool kernel/workqueue.c:2727 [inline]
 rescuer_thread+0xaf5/0x10a0 kernel/workqueue.c:3526
 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>

Showing all locks held in the system:
6 locks held by kworker/u8:1/12:
 #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90000117d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000117d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc51d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580
 #3: ffff88807a5d50e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #3: ffff88807a5d50e8 (&dev->mutex){....}-{3:3}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
 #3: ffff88807a5d50e8 (&dev->mutex){....}-{3:3}, at: devlink_pernet_pre_exit+0x13b/0x440 net/devlink/core.c:506
 #4: ffff88807a5d3250 (&devlink->lock_key#21){+.+.}-{3:3}, at: devl_lock net/devlink/core.c:276 [inline]
 #4: ffff88807a5d3250 (&devlink->lock_key#21){+.+.}-{3:3}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
 #4: ffff88807a5d3250 (&devlink->lock_key#21){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0x14d/0x440 net/devlink/core.c:506
 #5: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdevice_notifier_net+0x89/0x3a0 net/core/dev.c:1917
1 lock held by khungtaskd/30:
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
3 locks held by kworker/u8:2/35:
 #0: ffff88814b80d148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88814b80d148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90000ab7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000ab7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196
6 locks held by kworker/1:3/1567:
3 locks held by kworker/u8:8/2501:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90009447d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90009447d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
2 locks held by getty/4987:
 #0: ffff88803243a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
4 locks held by kworker/1:4/5280:
3 locks held by kworker/u8:14/7636:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc9000317fd00 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc9000317fd00 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: idle_cull_fn+0xd5/0x760 kernel/workqueue.c:2951
1 lock held by kworker/R-wg-cr/9362:
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: worker_attach_to_pool+0x31/0x390 kernel/workqueue.c:2669
1 lock held by kworker/R-wg-cr/9371:
1 lock held by kworker/R-wg-cr/9910:
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: worker_detach_from_pool kernel/workqueue.c:2727 [inline]
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: rescuer_thread+0xaf5/0x10a0 kernel/workqueue.c:3526
1 lock held by kworker/R-wg-cr/10373:
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: worker_attach_to_pool+0x31/0x390 kernel/workqueue.c:2669
1 lock held by kworker/R-wg-cr/11251:
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: worker_detach_from_pool kernel/workqueue.c:2727 [inline]
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: rescuer_thread+0xaf5/0x10a0 kernel/workqueue.c:3526
1 lock held by kworker/R-wg-cr/11253:
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: worker_detach_from_pool kernel/workqueue.c:2727 [inline]
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: rescuer_thread+0xaf5/0x10a0 kernel/workqueue.c:3526
1 lock held by kworker/1:0/11551:
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: set_pf_worker kernel/workqueue.c:3316 [inline]
 #0: ffffffff8e7e23a8 (wq_pool_attach_mutex){+.+.}-{3:3}, at: worker_thread+0x5c/0xd30 kernel/workqueue.c:3342
2 locks held by syz-executor/11660:
 #0: ffffffff8fcc51d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490
 #1: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: mpls_net_exit+0x7d/0x2a0 net/mpls/af_mpls.c:2706
2 locks held by syz-executor/11664:
 #0: ffffffff8fcc51d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490
 #1: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: fib6_rules_net_exit_batch+0x20/0xc0 net/ipv6/fib6_rules.c:547
2 locks held by syz-executor/11665:
 #0: ffffffff8fcc51d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490
 #1: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: cangw_pernet_exit_batch+0x20/0x90 net/can/gw.c:1257
3 locks held by syz-executor/11667:
 #0: ffffffff8fcc51d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490
 #1: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:11934
 #2: ffffffff8e7d1dd0 (cpu_hotplug_lock){++++}-{0:0}, at: flush_all_backlogs net/core/dev.c:6025 [inline]
 #2: ffffffff8e7d1dd0 (cpu_hotplug_lock){++++}-{0:0}, at: unregister_netdevice_many_notify+0x5ea/0x1da0 net/core/dev.c:11384
2 locks held by syz-executor/11669:
 #0: ffffffff8fcc51d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490
 #1: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: ppp_exit_net+0xe3/0x3d0 drivers/net/ppp/ppp_generic.c:1146
1 lock held by syz-executor/11675:
 #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
1 lock held by syz-executor/11679:
 #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
1 lock held by syz-executor/11684:
 #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
1 lock held by syz-executor/11687:
 #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x48c/0x2400 drivers/net/tun.c:3121
2 locks held by syz-executor/11691:
 #0: ffffffff8fcc51d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490
 #1: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 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: 1567 Comm: kworker/1:3 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: wg-crypt-wg0 wg_packet_tx_worker
RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:61 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:130 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x4f/0x290 mm/kasan/generic.c:189
Code: 89 fd 48 c1 ed 2f 81 fd fe ff 01 00 0f 86 43 02 00 00 48 89 fb 48 c1 eb 03 49 ba 00 00 00 00 00 fc ff df 4e 8d 1c 13 49 ff c8 <4d> 89 c1 49 c1 e9 03 49 be 01 00 00 00 00 fc ff df 4f 8d 3c 31 4c
RSP: 0018:ffffc90000a18970 EFLAGS: 00000092
RAX: 0000000000000001 RBX: 1ffffffff2039da5 RCX: ffffffff81707ce0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901ced28
RBP: 000000000001ffff R08: ffffffff901ced2f R09: 1ffffffff2858b1d
R10: dffffc0000000000 R11: fffffbfff2039da5 R12: 1ffff92000143140
R13: ffffffff89955c8b R14: dffffc0000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f00ea51ad58 CR3: 000000000e734000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 cpumask_test_cpu include/linux/cpumask.h:570 [inline]
 cpu_online include/linux/cpumask.h:1117 [inline]
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0xb0/0xa30 kernel/locking/lockdep.c:5836
 local_lock_release include/linux/local_lock_internal.h:38 [inline]
 process_backlog+0x1014/0x15b0 net/core/dev.c:6138
 __napi_poll+0xcb/0x490 net/core/dev.c:6775
 napi_poll net/core/dev.c:6844 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:6966
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 wg_socket_send_skb_to_peer+0x176/0x1d0 drivers/net/wireguard/socket.c:184
 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline]
 wg_packet_tx_worker+0x1bf/0x810 drivers/net/wireguard/send.c:276
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 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>


---
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