syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (2 ticks this GP) idle=445/1/0x4000000000000002 softirq=22869/22869 fqs=5246 
	(detected by 1, t=10502 jiffies, g=31189, q=1177)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9913 Comm: syz.5.1486 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_read_unlock_special+0x95/0x480 kernel/rcu/tree_plugin.h:674
Code: f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 48 c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 <66> 42 c7 44 2b 09 00 00 42 c6 44 2b 0b 00 65 48 8b 04 25 28 00 00
RSP: 0018:ffffc90000007020 EFLAGS: 00000046
RAX: ffffffff81839401 RBX: 1ffff92000000e08 RCX: ffff88805f568000
RDX: 0000000000000100 RSI: 0000000000000101 RDI: 0000000000000000
RBP: ffffc90000007100 R08: dffffc0000000000 R09: ffffed10172067af
R10: ffffed10172067af R11: 1ffff110172067ae R12: ffff8880b903b208
R13: dffffc0000000000 R14: ffff8880b903b200 R15: 1ffff11017207641
FS:  00007f00b3ed56c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32323ffc CR3: 0000000065dab000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 __perf_event_output kernel/events/core.c:7813 [inline]
 perf_event_output_forward+0x216/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900000077a0 EFLAGS: 00000206
RAX: 74d961331c32c600 RBX: 1ffff92000000ef8 RCX: 74d961331c32c600
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800
RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff5439
R10: fffffbfff1ff5439 R11: 1ffffffff1ff5438 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521
 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3956
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:227 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x13/0x80 kernel/kcov.c:300
Code: 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 65 48 8b 0d c4 9f 8a 7e 65 8b 15 c5 9f 8a 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 34 16 00 00
RSP: 0018:ffffc9000336f360 EFLAGS: 00000246
RAX: ffffffff813567b8 RBX: 000000005b8ad600 RCX: ffff88805f568000
RDX: 0000000080000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000336f640 R08: dffffc0000000000 R09: fffffbfff1ff541a
R10: fffffbfff1ff541a R11: 1ffffffff1ff5419 R12: ffffea0000000000
R13: ffff888074162b98 R14: 000000000000002e R15: 0000000000000000
 phys_addr_valid arch/x86/mm/physaddr.h:7 [inline]
 __phys_addr+0xa8/0x170 arch/x86/mm/physaddr.c:28
 virt_to_head_page include/linux/mm.h:911 [inline]
 ___cache_free+0x2a/0x120 mm/slub.c:3511
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 kmem_cache_zalloc include/linux/slab.h:728 [inline]
 __kernfs_new_node+0xd6/0x680 fs/kernfs/dir.c:593
 kernfs_new_node+0x148/0x250 fs/kernfs/dir.c:669
 __kernfs_create_file+0x47/0x2e0 fs/kernfs/file.c:985
 sysfs_add_file_mode_ns+0x2d4/0x3a0 fs/sysfs/file.c:317
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x489/0xcf0 fs/sysfs/group.c:149
 internal_create_groups fs/sysfs/group.c:189 [inline]
 sysfs_create_groups+0x55/0x120 fs/sysfs/group.c:215
 device_add_groups drivers/base/core.c:2491 [inline]
 device_add_attrs+0x83/0x6a0 drivers/base/core.c:2639
 device_add+0x64b/0xfb0 drivers/base/core.c:3363
 netdev_register_kobject+0x176/0x310 net/core/net-sysfs.c:2014
 register_netdevice+0x1019/0x16b0 net/core/dev.c:10397
 tun_set_iff+0x82a/0xda0 drivers/net/tun.c:2802
 __tun_chr_ioctl+0x722/0x1e70 drivers/net/tun.c:3062
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f00b5c6e749
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:00007f00b3ed5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f00b5ec4fa0 RCX: 00007f00b5c6e749
RDX: 00002000000000c0 RSI: 00000000400454ca RDI: 0000000000000006
RBP: 00007f00b5cf2f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00b5ec5038 R14: 00007f00b5ec4fa0 R15: 00007ffd3584bc18
 </TASK>