rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=c3d4/1/0x4000000000000000 softirq=24447/24449 fqs=5247 rcu: hardirqs softirqs csw/system rcu: number: 1341643 0 0 rcu: cputime: 16103 36376 63 ==> 52490(ms) rcu: (t=10501 jiffies g=29753 q=2398 ncpus=2) CPU: 0 PID: 7811 Comm: syz.3.600 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc900000078e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 473184ae8b70bd00 RDX: 0000000000000000 RSI: ffffffff8acadce0 RDI: ffffffff8b1c7be0 RBP: ffffc900000079e8 R08: dffffc0000000000 R09: 1ffffffff22378a0 R10: dffffc0000000000 R11: fffffbfff22378a1 R12: 1ffff92000000f28 R13: ffffffff8d131da0 R14: 0000000000000246 R15: dffffc0000000000 FS: 00007f7bd03306c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7d25def4b8 CR3: 0000000026235000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000f0602 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] __rhashtable_remove_fast include/linux/rhashtable.h:1084 [inline] rhashtable_remove_fast include/linux/rhashtable.h:1122 [inline] inet_frag_kill+0x303/0x10d0 net/ipv4/inet_fragment.c:280 ipq_kill net/ipv4/ip_fragment.c:123 [inline] ip_expire+0x19f/0x770 net/ipv4/ip_fragment.c:157 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x570/0x810 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x27d/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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:finish_task_switch+0x267/0x8f0 kernel/sched/core.c:5255 Code: 26 09 85 c0 0f 84 30 01 00 00 48 85 db 0f 85 4f 01 00 00 0f 1f 44 00 00 4c 89 e7 e8 93 3b 30 09 e8 7e 0b 30 00 fb 4c 8b 65 b8 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 RSP: 0018:ffffc9000fdbf580 EFLAGS: 00000282 RAX: 473184ae8b70bd00 RBX: 0000000000000000 RCX: 473184ae8b70bd00 RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1c7be0 RBP: ffffc9000fdbf5d0 R08: ffffffff911bc507 R09: 1ffffffff22378a0 R10: dffffc0000000000 R11: fffffbfff22378a1 R12: ffff88802b94da00 R13: 1ffff110171c79a9 R14: dffffc0000000000 R15: ffff8880b8e3cd48 context_switch kernel/sched/core.c:5384 [inline] __schedule+0x15b6/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 pcpu_alloc+0x287/0x1880 mm/percpu.c:1771 dev_map_notification+0x18f/0x9b0 kernel/bpf/devmap.c:1112 notifier_call_chain+0x18f/0x380 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline] call_netdevice_notifiers net/core/dev.c:2091 [inline] register_netdevice+0x1670/0x1ba0 net/core/dev.c:10351 tun_set_iff+0x82b/0xea0 drivers/net/tun.c:2865 __tun_chr_ioctl+0x7e0/0x2070 drivers/net/tun.c:3134 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7bcf39de59 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:00007f7bd0330028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7bcf625fa0 RCX: 00007f7bcf39de59 RDX: 0000200000000200 RSI: 00000000400454ca RDI: 000000000000000e RBP: 00007f7bcf433e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7bcf626038 R14: 00007f7bcf625fa0 R15: 00007ffc2ef5dda8