rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10498 ticks this GP) idle=ab9c/1/0x4000000000000000 softirq=19458/19459 fqs=4779
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:   821457          0            0
rcu: 	cputime:    28956      23522          122   ==> 52480(ms)
rcu: 	(t=10500 jiffies g=12237 q=2136 ncpus=2)
CPU: 0 UID: 0 PID: 6890 Comm: syz.2.343 Not tainted 6.16.0-rc6-syzkaller-00411-g95993dc3039e-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:rcu_read_unlock_special+0x87/0x4c0
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 62 2c f8 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900000073c0 EFLAGS: 00000206
RAX: f1cca89cb77db900 RBX: 1ffff92000000e80 RCX: f1cca89cb77db900
RDX: 0000000000000002 RSI: ffffffff8d99883e RDI: ffffffff8be29f40
RBP: ffffc900000074c0 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: ffffffff8e144400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
FS:  00007fea2d42f6c0(0000) GS:ffff8880b861f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c230000 CR3: 0000000026f7c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x84/0xe0
 is_module_text_address+0x190/0x1e0
 kernel_text_address+0x94/0xe0
 __kernel_text_address+0xd/0x40
 unwind_get_return_address+0x4d/0x90
 arch_stack_walk+0xfc/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 inet_frag_destroy+0x1f6/0x2a0
 ip_expire+0x5b5/0x8f0
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_irq_work+0xa3/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x1a/0x20
RIP: 0010:preempt_schedule_irq+0xb0/0x150
Code: 24 20 f6 44 24 21 02 74 0c 90 0f 0b 48 f7 03 08 00 00 00 74 64 bf 01 00 00 00 e8 8b 2d 21 f6 e8 c6 00 58 f6 fb bf 01 00 00 00 <e8> 1b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc900085b7b40 EFLAGS: 00000286
RAX: f1cca89cb77db900 RBX: 0000000000000000 RCX: f1cca89cb77db900
RDX: 0000000000000006 RSI: ffffffff8d99883e RDI: 0000000000000001
RBP: ffffc900085b7be0 R08: ffffffff8fa1e8f7 R09: 1ffffffff1f43d1e
R10: dffffc0000000000 R11: fffffbfff1f43d1f R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920010b6f68
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:should_failslab+0x93/0x100
Code: 48 c1 e9 03 42 0f b6 0c 21 84 c9 75 62 41 f6 47 01 40 74 37 c1 eb 0d 83 e3 01 49 83 c6 1c 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 <84> c0 75 2a 41 8b 36 48 c7 c7 40 07 26 8e 89 da e8 18 04 d1 02 31
RSP: 0018:ffffc900085b7ca0 EFLAGS: 00000a07
RAX: 0000000000000000 RBX: 0000000000000000 RCX: f1cca89cb77db900
RDX: ffff88810f8c1cc0 RSI: 0000000000400dc0 RDI: ffff88801a44b000
RBP: 0000000000400dc0 R08: 0000000000000000 R09: ffffffff8216016d
R10: ffff88802734da00 R11: ffffed1004e69b48 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88801a44b01c R15: ffff88801a44b000
 __kmalloc_cache_noprof+0x70/0x3d0
 alloc_netdev_mqs+0xbd5/0x11e0
 ppp_ioctl+0x634/0x19a0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fea2c58e9a9
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:00007fea2d42f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fea2c7b6080 RCX: 00007fea2c58e9a9
RDX: 000000110c230000 RSI: 00000000c004743e RDI: 000000000000000a
RBP: 00007fea2c610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fea2c7b6080 R15: 00007ffd4d78dd78
 </TASK>
sched: DL replenish lagged too much
