syzbot

INFO: task syz.3.1797:14150 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1797      state:D stack:24104 pid:14150 tgid:14150 ppid:5827   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 request_wait_answer fs/fuse/dev.c:565 [inline]
 __fuse_request_send fs/fuse/dev.c:579 [inline]
 __fuse_simple_request+0xf15/0x18d0 fs/fuse/dev.c:673
 fuse_simple_request fs/fuse/fuse_i.h:1237 [inline]
 fuse_flush+0x5d4/0x800 fs/fuse/file.c:475
 filp_flush+0xba/0x190 fs/open.c:1549
 filp_close+0x1d/0x40 fs/open.c:1562
 __range_close fs/file.c:752 [inline]
 __do_sys_close_range fs/file.c:811 [inline]
 __se_sys_close_range+0x359/0x650 fs/file.c:775
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c7ef8e929
RSP: 002b:00007fff1a8e7488 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007f4c7f1b7ba0 RCX: 00007f4c7ef8e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f4c7f1b7ba0 R08: 0000000000000b1c R09: 000000161a8e777f
R10: 00007f4c7f1b7ac0 R11: 0000000000000246 R12: 00000000000f1696
R13: 00007fff1a8e7580 R14: ffffffffffffffff R15: 00007fff1a8e75a0
 </TASK>
INFO: task syz.2.1798:14158 blocked for more than 145 seconds.
      Not tainted 6.16.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1798      state:D stack:24104 pid:14158 tgid:14158 ppid:5833   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 request_wait_answer fs/fuse/dev.c:565 [inline]
 __fuse_request_send fs/fuse/dev.c:579 [inline]
 __fuse_simple_request+0xf15/0x18d0 fs/fuse/dev.c:673
 fuse_simple_request fs/fuse/fuse_i.h:1237 [inline]
 fuse_flush+0x5d4/0x800 fs/fuse/file.c:475
 filp_flush+0xba/0x190 fs/open.c:1549
 filp_close+0x1d/0x40 fs/open.c:1562
 __range_close fs/file.c:752 [inline]
 __do_sys_close_range fs/file.c:811 [inline]
 __se_sys_close_range+0x359/0x650 fs/file.c:775
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f128df8e929
RSP: 002b:00007fffe32d0df8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007f128e1b7ba0 RCX: 00007f128df8e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f128e1b7ba0 R08: 000000000001741c R09: 00000016e32d10ef
R10: 00007f128e1b7ac0 R11: 0000000000000246 R12: 00000000000f198a
R13: 00007fffe32d0ef0 R14: ffffffffffffffff R15: 00007fffe32d0f10
 </TASK>
INFO: task syz.5.1835:14273 blocked for more than 146 seconds.
      Not tainted 6.16.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1835      state:D stack:24104 pid:14273 tgid:14273 ppid:9331   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 request_wait_answer fs/fuse/dev.c:565 [inline]
 __fuse_request_send fs/fuse/dev.c:579 [inline]
 __fuse_simple_request+0xf15/0x18d0 fs/fuse/dev.c:673
 fuse_simple_request fs/fuse/fuse_i.h:1237 [inline]
 fuse_flush+0x5d4/0x800 fs/fuse/file.c:475
 filp_flush+0xba/0x190 fs/open.c:1549
 filp_close+0x1d/0x40 fs/open.c:1562
 __range_close fs/file.c:752 [inline]
 __do_sys_close_range fs/file.c:811 [inline]
 __se_sys_close_range+0x359/0x650 fs/file.c:775
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b4898e929
RSP: 002b:00007fff14f74ac8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007f1b48bb7ba0 RCX: 00007f1b4898e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f1b48bb7ba0 R08: 000000000001b074 R09: 0000001714f74dbf
R10: 00007f1b48bb7ac0 R11: 0000000000000246 R12: 00000000000f4a16
R13: 00007fff14f74bc0 R14: ffffffffffffffff R15: 00007fff14f74be0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5584:
 #0: ffff888030bdc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/1:4/5898:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc9000455fbc0 (key_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000455fbc0 (key_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #2: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
2 locks held by kworker/1:5/5906:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc900045dfbc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900045dfbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
4 locks held by kworker/u8:15/11493:
 #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc9001b967bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9001b967bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8f4f0fd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
 #3: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: mpls_net_exit+0x79/0x270 net/mpls/af_mpls.c:2706
1 lock held by syz.1.1803/14179:
1 lock held by syz-executor/14799:
 #0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
 #0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396
2 locks held by syz.6.2030/15089:
 #0: ffff88802174cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
 #0: ffff88802174cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2691
 #1: ffff88802174c078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5238
1 lock held by syz-executor/15098:
 #0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f4fdbc8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3446 Comm: kworker/u8:8 Not tainted 6.16.0-rc3-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_switch+0xb3/0x130 kernel/kcov.c:351
Code: 77 4e 8b 54 ce 10 65 44 8b 1d f9 5d d9 10 41 81 e3 00 01 ff 00 74 13 41 81 fb 00 01 00 00 75 d9 41 83 b8 3c 16 00 00 00 74 cf <45> 8b 98 18 16 00 00 41 83 fb 03 75 c2 4d 8b 98 20 16 00 00 45 8b
RSP: 0018:ffffc9000c89eb28 EFLAGS: 00000046
RAX: 0000000000000020 RBX: ffff88801dabb36c RCX: 0000000000000005
RDX: ffffffff81c41700 RSI: ffffffff8e195010 RDI: 0000000000000004
RBP: 0000010bcf5f36be R08: ffff888030f55a00 R09: 0000000000000007
R10: 0000000000000007 R11: 0000000000000000 R12: ffff88801dabb010
R13: 0000000000000004 R14: 000000000004f044 R15: 000000000000035c
FS:  0000000000000000(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000001d000 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rb_read_data_buffer+0x110/0x580 kernel/trace/ring_buffer.c:1820
 check_buffer+0x28a/0x750 kernel/trace/ring_buffer.c:4296
 __rb_reserve_next+0x592/0xdb0 kernel/trace/ring_buffer.c:4395
 rb_reserve_next_event kernel/trace/ring_buffer.c:4532 [inline]
 ring_buffer_lock_reserve+0xbb5/0x1010 kernel/trace/ring_buffer.c:4591
 __trace_buffer_lock_reserve kernel/trace/trace.c:1090 [inline]
 trace_event_buffer_lock_reserve+0x1d0/0x6f0 kernel/trace/trace.c:2837
 trace_event_buffer_reserve+0x248/0x340 kernel/trace/trace_events.c:672
 do_trace_event_raw_event_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline]
 trace_event_raw_event_bpf_trace_printk+0x100/0x260 kernel/trace/bpf_trace.h:11
 __do_trace_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline]
 trace_bpf_trace_printk+0x170/0x1d0 kernel/trace/bpf_trace.h:11
 ____bpf_trace_printk kernel/trace/bpf_trace.c:380 [inline]
 bpf_trace_printk+0x11e/0x190 kernel/trace/bpf_trace.c:363
 bpf_prog_9e1c00255e17e72e+0x39/0x3f
 bpf_dispatcher_nop_func include/linux/bpf.h:1322 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline]
 bpf_trace_run1+0x27f/0x4b0 kernel/trace/bpf_trace.c:2298
 __bpf_trace_rcu_utilization+0xa1/0xf0 include/trace/events/rcu.h:27
 __traceiter_rcu_utilization+0x7a/0xb0 include/trace/events/rcu.h:27
 __do_trace_rcu_utilization include/trace/events/rcu.h:27 [inline]
 trace_rcu_utilization+0x1ad/0x1d0 include/trace/events/rcu.h:27
 rcu_note_context_switch+0xdc1/0x1140 kernel/rcu/tree_plugin.h:372
 __schedule+0x326/0x4cb0 kernel/sched/core.c:6690
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 on_each_cpu_cond_mask+0x7a/0x80 kernel/smp.c:1053
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline]
 smp_text_poke_batch_finish+0xe6a/0x1100 arch/x86/kernel/alternative.c:2984
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240
 static_key_disable+0x1a/0x20 kernel/jump_label.c:248
 toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:855
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>