syzbot

INFO: task syz.0.64:6117 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.64        state:D stack:23144 pid:6117  ppid:5918   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 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
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x90b/0x23c0 kernel/exit.c:883
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 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: 0033:0x7fd4a498f6c9
RSP: 002b:00007ffe5557b198 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffff2 RBX: 00007fd4a4be5fa0 RCX: 00007fd4a498f6c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000
RBP: 00007fd4a4a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fd4a4be5fa0 R14: 00007fd4a4be5fa0 R15: 0000000000000006
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5551:
 #0: ffff88823bde20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by syz.2.90/6791:

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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: 6791 Comm: syz.2.90 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215
Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 0c 00 c5 0c 48 89 de 5b e9 a3 8a 56 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 20 28 7e 7e 65 8b 15 21 28 7e 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900001f0558 EFLAGS: 00000086
RAX: ffffffff813ad979 RBX: ffffc90004b07f78 RCX: ffff888017f51e00
RDX: 0000000000010000 RSI: ffffffff8cb9e7a0 RDI: ffffc90004b07f78
RBP: ffffc900001f06f0 R08: ffff888017f51e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000010000 R12: ffffc900001f06a0
R13: dffffc0000000000 R14: ffffc90004b07f78 R15: ffffc900001f06d6
FS:  000055555b516500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c9ad601000 CR3: 0000000024aa1000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 __read_once_word_nocheck+0x9/0x10 include/asm-generic/rwonce.h:66
 get_reg arch/x86/kernel/unwind_orc.c:-1 [inline]
 unwind_next_frame+0x1bf9/0x2970 arch/x86/kernel/unwind_orc.c:643
 perf_callchain_kernel+0x465/0x5c0 arch/x86/events/core.c:2780
 get_perf_callchain+0x223/0x4d0 kernel/events/callchain.c:204
 perf_callchain kernel/events/core.c:7740 [inline]
 perf_sample_save_callchain include/linux/perf_event.h:1232 [inline]
 perf_prepare_sample+0x3a2/0x1d20 kernel/events/core.c:7784
 __perf_event_output kernel/events/core.c:7972 [inline]
 perf_event_output_forward+0x152/0x3a0 kernel/events/core.c:7993
 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9718
 perf_swevent_hrtimer+0x3bc/0x530 kernel/events/core.c:11188
 __run_hrtimer kernel/time/hrtimer.c:1750 [inline]
 __hrtimer_run_queues+0x4df/0xc40 kernel/time/hrtimer.c:1814
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
 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+0x9f/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+0x5/0xc0 arch/x86/kernel/unwind_orc.c:365
Code: d9 80 e1 07 80 c1 03 38 c1 0f 8c 49 ff ff ff 48 89 df e8 2e 49 a2 00 e9 3c ff ff ff e8 14 2b 34 09 0f 1f 40 00 f3 0f 1e fa 55 <41> 57 41 56 53 48 89 fb 49 be 00 00 00 00 00 fc ff df e8 d4 ed 4a
RSP: 0018:ffffc90004b06b98 EFLAGS: 00000293
RAX: ffffffff81321b22 RBX: ffffc90004b06c60 RCX: ffff888017f51e00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: ffffc90004b06ba8
RBP: ffffc90004b06c30 R08: ffff888017f51e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff890a1e63
R13: 00000000000000b8 R14: ffffffff81746cb0 R15: ffffc90004b06ba8
 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:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3519
 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:1068
 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
 netdev_queue_add_kobject net/core/net-sysfs.c:1699 [inline]
 netdev_queue_update_kobjects+0x228/0x480 net/core/net-sysfs.c:1745
 register_queue_kobjects net/core/net-sysfs.c:1806 [inline]
 netdev_register_kobject+0x269/0x310 net/core/net-sysfs.c:2046
 register_netdevice+0x128f/0x1ae0 net/core/dev.c:10280
 __ip_tunnel_create+0x3b4/0x4c0 net/ipv4/ip_tunnel.c:267
 ip_tunnel_init_net+0x2c3/0x770 net/ipv4/ip_tunnel.c:1104
 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: 0033:0x7f5b82f8f6c9
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:00007fff14a722a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f5b831e5fa0 RCX: 00007f5b82f8f6c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000
RBP: 00007f5b83011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f5b831e5fa0 R14: 00007f5b831e5fa0 R15: 0000000000000006
 </TASK>