rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=1e3c/1/0x4000000000000000 softirq=35921/35921 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=26873, q=260 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 10519 Comm: syz.1.1301 Not tainted syzkaller #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:hrtimer_try_to_cancel+0x22b/0x420
Code: 2c 24 49 81 fd 00 db 15 8e 74 66 4c 89 eb 48 c1 eb 03 42 80 3c 33 00 74 08 4c 89 ef e8 ae 9c 75 00 49 8b 7d 00 e8 c5 53 cf 09 <49> 89 c7 48 8b 44 24 10 42 80 3c 30 00 74 08 4c 89 e7 e8 8e 9c 75
RSP: 0018:ffffc900001dff28 EFLAGS: 00000046
RAX: 0000000000000802 RBX: 1ffff11026cc4f60 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900001dfe00
RBP: 000000000040065a R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003bfc0 R12: ffff8880380d2d58
R13: ffff888136627b00 R14: dffffc0000000000 R15: ffff888136627b00
FS:  00007f051bc2a6c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f68fbe58fc8 CR3: 00000000332b0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:deref_stack_reg+0x54/0x230
Code: 49 c1 ec 03 41 80 3c 34 00 4c 89 04 24 74 16 48 89 df e8 ef 4c b0 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 48 89 5c 24 10 <49> 8b 5f 08 4d 8d 77 10 4d 89 f5 49 c1 ed 03 41 80 7c 35 00 00 74
RSP: 0018:ffffc900001e06c0 EFLAGS: 00000246
RAX: fffffffffffffff0 RBX: ffffc900001e07f0 RCX: 0000000000000000
RDX: ffffc900001e0828 RSI: dffffc0000000000 RDI: ffffc900001e07e8
RBP: dffffc0000000000 R08: ffffc900001e0920 R09: 0000000000000000
R10: ffffc900001e0838 R11: fffff5200003c109 R12: 1ffff9200003c0fe
R13: ffffc900001e0838 R14: ffffc900001e07e8 R15: ffffc900001e07e8
 unwind_next_frame+0x17c4/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:do_syscall_64+0xc3/0x3b0
Code: 00 48 8b 7d 08 48 89 7b 18 e8 09 5a 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 39 5b 4d f6 90 90 e8 e2 5a 4d f6 fb 49 8b 57 08 <f6> c2 3f 74 0e 4c 89 f7 4c 89 ee e8 fd 4d 30 f6 49 89 c4 90 90 41
RSP: 0018:ffffc90001cefef0 EFLAGS: 00000286
RAX: f3a7d824d4a24800 RBX: ffffc90001cefef0 RCX: f3a7d824d4a24800
RDX: 0000000000000000 RSI: ffffffff8d9ba2f8 RDI: ffffffff8be33e80
RBP: ffffc90001ceff48 R08: ffffffff8fa3aa37 R09: 1ffffffff1f47546
R10: dffffc0000000000 R11: fffffbfff1f47547 R12: 0000000000000029
R13: 0000000000000029 R14: ffffc90001ceff58 R15: ffff88802202d640
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f051ad8eba9
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:00007f051bc2a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f051afd5fa0 RCX: 00007f051ad8eba9
RDX: 0000000000000010 RSI: 0000000000000002 RDI: 0000000000000010
RBP: 00007f051ae11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f051afd6038 R14: 00007f051afd5fa0 R15: 00007ffddb2e7d28
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g26873 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27160 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 10522 Comm: syz.0.1302 Not tainted syzkaller #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:__sanitizer_cov_trace_pc+0x0/0x70
Code: 89 fb e8 23 00 00 00 48 8b 3d 94 73 fe 0b 48 89 de 5b e9 53 b1 58 00 cc cc cc 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 d0 a0 92 65 8b 15 b8 0e
RSP: 0018:ffffc90001ccf538 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 1ffff11026cc7f61 RCX: 0000000000080000
RDX: ffffc90028205000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90001ccf6c0 R08: ffffffff8fa3aa37 R09: 1ffffffff1f47546
R10: dffffc0000000000 R11: fffffbfff1f47547 R12: ffff88813663fb08
R13: dffffc0000000000 R14: ffff88804b03b1c0 R15: 0000000000000001
FS:  00007f68fbe596c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003040 CR3: 000000010ed00000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 smp_call_function_many_cond+0xd4b/0x12d0
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 dup_mmap+0x15a0/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68faf8eba9
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:00007f68fbe58fe8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f68fb1d5fa0 RCX: 00007f68faf8eba9
RDX: 0000200000003080 RSI: 0000200000003040 RDI: 0000000004908480
RBP: 00007f68fb011e19 R08: 0000200000003100 R09: 0000200000003100
R10: 00002000000030c0 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f68fb1d6038 R14: 00007f68fb1d5fa0 R15: 00007ffd3add60f8
 </TASK>
