watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.2.10:5960] Modules linked in: irq event stamp: 21509649 hardirqs last enabled at (21509648): [] irqentry_exit+0x63/0x90 kernel/entry/common.c:357 hardirqs last disabled at (21509649): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1049 softirqs last enabled at (96250): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last enabled at (96250): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last enabled at (96250): [] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 softirqs last disabled at (96253): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last disabled at (96253): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last disabled at (96253): [] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 CPU: 0 UID: 0 PID: 5960 Comm: syz.2.10 Not tainted 6.14.0-syzkaller-g25601e85441d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:rcu_read_unlock_special+0x8a/0x570 kernel/rcu/tree_plugin.h:694 Code: f1 f1 f1 00 f2 f2 f2 49 89 04 14 66 41 c7 44 14 09 f3 f3 41 c6 44 14 0b f3 65 44 8b 3d df bc be 11 41 f7 c7 00 00 f0 00 74 44 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 22 00 00 00 00 66 42 c7 44 22 RSP: 0018:ffffc90000006f40 EFLAGS: 00000206 RAX: 5afb26bc78fb4200 RBX: 1ffff92000000df0 RCX: ffffffff93684020 RDX: dffffc0000000000 RSI: ffffffff8e697da5 RDI: ffffffff8ca1ab00 RBP: ffffc90000007020 R08: ffffffff905fb577 R09: 1ffffffff20bf6ae R10: dffffc0000000000 R11: fffffbfff20bf6af R12: 1ffff92000000dec R13: ffff88802608c060 R14: ffffc90000006f80 R15: ffffffff8ed42d00 FS: 00007fe8491706c0(0000) GS:ffff888124f9c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f307de00020 CR3: 0000000030fb8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __rcu_read_unlock+0xa1/0x110 kernel/rcu/tree_plugin.h:438 rcu_read_unlock include/linux/rcupdate.h:873 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x1aa4/0x23b0 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free_freelist_hook mm/slub.c:2418 [inline] slab_free_bulk mm/slub.c:4670 [inline] kmem_cache_free_bulk+0x2da/0x530 mm/slub.c:5247 kfree_skb_list_reason+0x6d3/0x760 net/core/skbuff.c:1264 __dev_xmit_skb net/core/dev.c:4097 [inline] __dev_queue_xmit+0x2339/0x3f60 net/core/dev.c:4599 lapb_data_transmit+0x91/0xb0 net/lapb/lapb_iface.c:447 lapb_transmit_buffer+0x168/0x1f0 net/lapb/lapb_out.c:149 lapb_t1timer_expiry+0x6b8/0xb20 net/lapb/lapb_timer.c:-1 call_timer_fn+0x189/0x650 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1840 [inline] __run_timers kernel/time/timer.c:2414 [inline] __run_timer_base+0x66e/0x8e0 kernel/time/timer.c:2426 run_timer_base kernel/time/timer.c:2435 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd9/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 2b 00 74 08 4c 89 f7 e8 4d 4c fb f5 f6 44 24 21 02 75 55 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 d2 5b 5e f5 65 8b 05 5b 11 36 07 85 c0 74 46 48 c7 04 24 0e 36 RSP: 0018:ffffc9000aedf620 EFLAGS: 00000206 RAX: 5afb26bc78fb4200 RBX: 1ffff920015dbec8 RCX: 0000000000000006 RDX: 0000000000000006 RSI: ffffffff8e697da5 RDI: 0000000000000001 RBP: ffffc9000aedf6b0 R08: ffffffff905fb577 R09: 1ffffffff20bf6ae R10: dffffc0000000000 R11: fffffbfff20bf6af R12: 1ffff920015dbec4 R13: dffffc0000000000 R14: ffffc9000aedf640 R15: 0000000000000246 rwsem_wake kernel/locking/rwsem.c:1211 [inline] __up_write kernel/locking/rwsem.c:1374 [inline] up_write+0x315/0x590 kernel/locking/rwsem.c:1630 kernfs_add_one+0x286/0x530 fs/kernfs/dir.c:824 __kernfs_create_file+0x22e/0x2e0 fs/kernfs/file.c:1067 sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:319 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x7ea/0x1320 fs/sysfs/group.c:183 internal_create_groups fs/sysfs/group.c:223 [inline] sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:249 device_add_groups drivers/base/core.c:2813 [inline] device_add_attrs+0xef/0x670 drivers/base/core.c:2877 device_add+0x576/0xbf0 drivers/base/core.c:3620 netdev_register_kobject+0x157/0x2f0 net/core/net-sysfs.c:2336 register_netdevice+0x12b0/0x1b80 net/core/dev.c:11011 tun_set_iff+0x859/0xee0 drivers/net/tun.c:2781 __tun_chr_ioctl+0x7ef/0x1f90 drivers/net/tun.c:3048 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe84838d169 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:00007fe849170038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe8485a5fa0 RCX: 00007fe84838d169 RDX: 0000200000000040 RSI: 00000000400454ca RDI: 0000000000000008 RBP: 00007fe84840e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe8485a5fa0 R15: 00007ffd8eb60288 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18 Comm: rcu_exp_gp_kthr Not tainted 6.14.0-syzkaller-g25601e85441d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 74 ed b5 0c 48 89 de 5b e9 63 b1 5e 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 40 68 93 65 8b 15 38 e9 a4 11 81 e2 00 01 ff 00 RSP: 0018:ffffc900001772b8 EFLAGS: 00000296 RAX: ffffffff81a39d53 RBX: fffffffffffea870 RCX: ffff88801d6c9e00 RDX: ffff88801d6c9e00 RSI: fffffffffffea870 RDI: 0000000000000001 RBP: ffffc90000177470 R08: ffffffff81a39aa6 R09: ffffffff81a399d9 R10: 0000000000000003 R11: ffff88801d6c9e00 R12: ffffc900001774c0 R13: dffffc0000000000 R14: 00000000000009e8 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff88812509c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f307e7fa20c CR3: 000000007dc54000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1894 [inline] prb_read kernel/printk/printk_ringbuffer.c:1942 [inline] _prb_read_valid+0xb93/0xbb0 kernel/printk/printk_ringbuffer.c:2113 prb_read_valid+0xab/0xf0 kernel/printk/printk_ringbuffer.c:2185 printk_get_next_message+0x1f5/0x8b0 kernel/printk/printk.c:3005 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x56b/0xec0 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0x151/0x3b0 kernel/printk/printk.c:3325 vprintk_emit+0x761/0xa40 kernel/printk/printk.c:2450 _printk+0xd5/0x120 kernel/printk/printk.c:2475 synchronize_rcu_expedited_stall kernel/rcu/tree_exp.h:570 [inline] synchronize_rcu_expedited_wait kernel/rcu/tree_exp.h:668 [inline] rcu_exp_wait_wake kernel/rcu/tree_exp.h:687 [inline] rcu_exp_sel_wait_wake+0x8d4/0x1dd0 kernel/rcu/tree_exp.h:721 kthread_worker_fn+0x508/0xbb0 kernel/kthread.c:1010 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245