rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=5044/1/0x4000000000000000 softirq=25601/25601 fqs=4426
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1341389          0            0
rcu: 	cputime:    18617      33872           72   ==> 52490(ms)
rcu: 	(t=10500 jiffies g=29561 q=792 ncpus=2)
CPU: 1 PID: 8711 Comm: syz.3.927 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ipv6_ext_hdr+0x5/0x80 net/ipv6/exthdrs_core.c:14
Code: f8 48 8b 3b e8 cc 29 6b f8 4c 89 f7 5b 41 5e 41 5f e9 8f 0e 6c f8 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 53 <89> fb e8 84 4c 2e f8 89 df 48 c7 c6 30 35 4f 8e e8 36 51 2e f8 83
RSP: 0018:ffffc900001f0670 EFLAGS: 00000212
RAX: 1ffff9200003e0ec RBX: dffffc0000000000 RCX: 0000000000000100
RDX: ffff8880247c8000 RSI: 000000000000003a RDI: 000000000000003a
RBP: ffffc900001f0858 R08: dffffc0000000000 R09: 1ffffffff2238ca0
R10: dffffc0000000000 R11: fffffbfff2238ca1 R12: ffff88801b3afbb0
R13: 0000000000000008 R14: 000000000000003a R15: 000000000000003a
FS:  00007fe3d76d26c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000001f3ea000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600
Call Trace:
 <IRQ>
 find_prev_fhdr net/ipv6/netfilter/nf_conntrack_reasm.c:407 [inline]
 nf_ct_frag6_gather+0x325/0x1eb0 net/ipv6/netfilter/nf_conntrack_reasm.c:459
 ipv6_defrag+0x2a9/0x3a0 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:67
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:259 [inline]
 NF_HOOK include/linux/netfilter.h:302 [inline]
 ndisc_send_skb+0x138a/0x14f0 net/ipv6/ndisc.c:513
 addrconf_rs_timer+0x2d5/0x630 net/ipv6/addrconf.c:4024
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x542/0x800 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 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+0xd3/0x190 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:generic_exec_single+0x481/0x4f0 kernel/smp.c:418
Code: 75 11 e8 42 05 0b 00 48 85 db 75 16 e8 38 05 0b 00 eb 15 e8 31 05 0b 00 e8 0c 4e 0a 09 48 85 db 74 ea e8 22 05 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 43 c7 44 2c 08
RSP: 0018:ffffc90004fbfa00 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc9000d1bc000 RSI: 0000000000001c8d RDI: 0000000000001c8e
RBP: ffffc90004fbfad0 R08: ffffffff911c65ff R09: 1ffffffff2238cbf
R10: dffffc0000000000 R11: fffffbfff2238cc0 R12: 1ffff920009f7f44
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920009f7f65
 smp_call_function_single+0x36d/0x5a0 kernel/smp.c:647
 task_function_call kernel/events/core.c:120 [inline]
 perf_install_in_context+0x5be/0x920 kernel/events/core.c:2959
 __do_sys_perf_event_open kernel/events/core.c:12957 [inline]
 __se_sys_perf_event_open+0x1836/0x1c50 kernel/events/core.c:12609
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe3d679cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe3d76d2028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fe3d6a15fa0 RCX: 00007fe3d679cdd9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007fe3d6832d69 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe3d6a16038 R14: 00007fe3d6a15fa0 R15: 00007ffccdbac3a8
 </TASK>