syzbot

INFO: task syz.0.25:5998 blocked for more than 143 seconds.
      Not tainted 6.6.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.25        state:D stack:22568 pid:5998  ppid:5915   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14e2/0x4580 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 perf_pending_task_sync kernel/events/core.c:5242 [inline]
 _free_event+0x174/0xf30 kernel/events/core.c:5248
 put_event kernel/events/core.c:5376 [inline]
 perf_event_release_kernel+0x836/0x8c0 kernel/events/core.c:5501
 perf_release+0x3b/0x40 kernel/events/core.c:5511
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 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:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdc66d8e929
RSP: 002b:00007ffc1804c238 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000034455 RCX: 00007fdc66d8e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 000000031804c52f
R10: 00007fdc66a00000 R11: 0000000000000246 R12: 00007fdc66fb5fac
R13: 00007fdc66fb5fa0 R14: ffffffffffffffff R15: 0000000000000006
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5548:
 #0: ffff888031c020a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
3 locks held by syz.2.46/6113:

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf41/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6113 Comm: syz.2.46 Not tainted 6.6.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__lock_acquire+0x19f/0x7c80 kernel/locking/lockdep.c:5034
Code: e8 b6 dd ff ff 49 b8 00 00 00 00 00 fc ff df 49 89 c5 48 85 c0 0f 84 21 1a 00 00 48 8b 44 24 20 48 8d 98 d8 0a 00 00 48 89 d8 <48> c1 e8 03 48 89 44 24 78 42 0f b6 04 00 84 c0 0f 85 2a 66 00 00
RSP: 0018:ffffc900001efae0 EFLAGS: 00000082
RAX: ffff888026b40ad8 RBX: ffff888026b40ad8 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff8d3d6f20
RBP: ffffc900001efd28 R08: dffffc0000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff1c94ff6 R12: 0000000000000001
R13: ffffffff9070d3e0 R14: ffffffff8d3d6f28 R15: 0000000000000000
FS:  000055556af93500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c006db2000 CR3: 0000000024e62000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 debug_objects_fill_pool+0x92/0x6b0 lib/debugobjects.c:615
 debug_object_activate+0x36/0x4b0 lib/debugobjects.c:705
 debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline]
 debug_activate kernel/time/hrtimer.c:505 [inline]
 enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1113
 __run_hrtimer kernel/time/hrtimer.c:1772 [inline]
 __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1819
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:check_preemption_disabled+0x13/0x110 lib/smp_processor_id.c:13
Code: fc 8a 48 c7 c6 e0 6c fc 8a eb 0c 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 <48> 89 44 24 08 65 8b 05 cd 3c 95 75 65 8b 0d c2 3c 95 75 f7 c1 ff
RSP: 0018:ffffc900001f03f8 EFLAGS: 00000282
RAX: 6cca165f47e91d00 RBX: 00007f700238e929 RCX: dffffc0000000000
RDX: 0000000000000100 RSI: ffffffff8afc6ce0 RDI: ffffffff8afc6ca0
RBP: 0000000000000001 R08: ffff888026b40000 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8a8000d0
R13: 00000000000000f0 R14: dffffc0000000000 R15: 1ffff9200003e09e
 rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
 rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:700
 kernel_text_address+0x7b/0xd0 kernel/extable.c:113
 __kernel_text_address+0xd/0x30 kernel/extable.c:79
 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369
 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3530
 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
 __netdev_alloc_skb+0x10c/0x500 net/core/skbuff.c:714
 netdev_alloc_skb include/linux/skbuff.h:3249 [inline]
 dev_alloc_skb include/linux/skbuff.h:3262 [inline]
 __ieee80211_beacon_get+0xe17/0x1600 net/mac80211/tx.c:5437
 ieee80211_beacon_get_tim+0xb8/0x560 net/mac80211/tx.c:5559
 ieee80211_beacon_get include/net/mac80211.h:5438 [inline]
 mac80211_hwsim_beacon_tx+0x3c7/0x780 drivers/net/wireless/virtual/mac80211_hwsim.c:2265
 __iterate_interfaces+0x243/0x500 net/mac80211/util.c:766
 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:802
 mac80211_hwsim_beacon+0xbb/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2295
 __run_hrtimer kernel/time/hrtimer.c:1755 [inline]
 __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1819
 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1836
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:unwind_get_return_address+0x5f/0xc0 arch/x86/kernel/unwind_orc.c:369
Code: 4b 00 85 ed 74 4a 48 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 cb b3 a3 00 48 8b 3b e8 c3 d4 1d 00 89 c5 <31> ff 89 c6 e8 88 08 4b 00 85 ed 74 20 e8 cf 04 4b 00 43 80 3c 37
RSP: 0018:ffffc90003826a80 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc90003826af0 RCX: 0000000000000000
RDX: ffff888026b40001 RSI: 0000000000000001 RDI: ffffffff814fbd8b
RBP: 0000000000000001 R08: ffff888026b40000 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff814f54a0
R13: 00000000000000b8 R14: dffffc0000000000 R15: 1ffff92000704d5e
 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3493 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3500 [inline]
 kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 __kernfs_new_node+0xd8/0x7e0 fs/kernfs/dir.c:624
 kernfs_new_node+0x14c/0x260 fs/kernfs/dir.c:700
 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1050
 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:294
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x428/0xd00 fs/sysfs/group.c:152
 internal_create_groups fs/sysfs/group.c:192 [inline]
 sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:218
 device_add_groups drivers/base/core.c:2785 [inline]
 device_add_attrs+0x1b2/0x810 drivers/base/core.c:2905
 device_add+0x528/0xc20 drivers/base/core.c:3637
 netdev_register_kobject+0x17a/0x310 net/core/net-sysfs.c:2042
 register_netdevice+0x128f/0x1ae0 net/core/dev.c:10268
 __ip_tunnel_create+0x3b4/0x4c0 net/ipv4/ip_tunnel.c:267
 ip_tunnel_init_net+0x2c3/0x770 net/ipv4/ip_tunnel.c:1118
 vti_init_net+0x2f/0xf0 net/ipv4/ip_vti.c:504
 ops_init+0x397/0x640 net/core/net_namespace.c:139
 setup_net+0x3a5/0xa00 net/core/net_namespace.c:343
 copy_net_ns+0x36d/0x5e0 net/core/net_namespace.c:520
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 copy_namespaces+0x430/0x4a0 kernel/nsproxy.c:179
 copy_process+0x1700/0x3d70 kernel/fork.c:2509
 kernel_clone+0x21b/0x840 kernel/fork.c:2914
 __do_sys_clone kernel/fork.c:3057 [inline]
 __se_sys_clone kernel/fork.c:3041 [inline]
 __x64_sys_clone+0x18c/0x1e0 kernel/fork.c:3041
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f700238e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe41116f08 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f70025b5fa0 RCX: 00007f700238e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000
RBP: 00007f7002410b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f70025b5fa0 R14: 00007f70025b5fa0 R15: 0000000000000006
 </TASK>