rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=13e4/1/0x4000000000000000 softirq=92952/92953 fqs=5
rcu: 	(detected by 0, t=10502 jiffies, g=142685, q=14 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5580 Comm: kworker/u4:15 Not tainted 6.3.0-rc4-syzkaller-00034-gfcd476ea6a88 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/17/2023
Workqueue: loop4 loop_workfn
RIP: 0010:kasan_check_range+0x1b4/0x290 mm/kasan/generic.c:187
Code: 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 39 00 0f 85 a2 00 00 00 49 ff c1 48 ff cd 75 ee 5b 41 5e 41 5f <5d> c3 45 84 f6 75 61 41 f7 c6 00 ff 00 00 75 5d 41 f7 c6 00 00 ff
RSP: 0018:ffffc900001e0c90 EFLAGS: 00000056
RAX: ffffffff8a9aae01 RBX: 0000000000000018 RCX: ffffffff8a9aae90
RDX: 0000000000000001 RSI: 0000000000000018 RDI: ffff88803a93a340
RBP: 0000000000000003 R08: dffffc0000000000 R09: ffffed100752746b
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b992b950
R13: ffff8880b992b950 R14: 0000000000000000 R15: ffff88803a93a340
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3488f0e2c3 CR3: 000000009298b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __asan_memset+0x23/0x40 mm/kasan/shadow.c:84
 rb_link_node include/linux/rbtree.h:63 [inline]
 rb_add_cached include/linux/rbtree.h:182 [inline]
 timerqueue_add+0x200/0x280 lib/timerqueue.c:40
 enqueue_hrtimer+0x151/0x310 kernel/time/hrtimer.c:1091
 __run_hrtimer kernel/time/hrtimer.c:1702 [inline]
 __hrtimer_run_queues+0x6c0/0xd10 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x396/0x980 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
 __sysvec_apic_timer_interrupt+0x13f/0x480 arch/x86/kernel/apic/apic.c:1113
 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1107
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x17/0x60 kernel/kcov.c:207
Code: 48 8b 3d b4 36 c9 0c 48 89 de 5b e9 e3 e0 54 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 80 61 79 7e 65 8b 15 81 61 79 7e <f7> c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 74 15 00 00
RSP: 0018:ffffc90006baf4f8 EFLAGS: 00000293
RAX: ffffffff81c283c4 RBX: ffffea00011c1840 RCX: ffff8880286857c0
RDX: 0000000080000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90006baf6e0 R08: ffffffff81c28158 R09: fffff94000238309
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000d75ecc R14: 0000000000000000 R15: ffff888012473c00
 shmem_get_folio_gfp+0x674/0x36b0 mm/shmem.c:1898
 shmem_get_folio mm/shmem.c:2068 [inline]
 shmem_file_read_iter+0x279/0xa70 mm/shmem.c:2633
 do_iter_read+0x71a/0xc70 fs/read_write.c:796
 lo_read_simple drivers/block/loop.c:290 [inline]
 do_req_filebacked drivers/block/loop.c:500 [inline]
 loop_handle_cmd drivers/block/loop.c:1888 [inline]
 loop_process_work+0xc85/0x2220 drivers/block/loop.c:1923
 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2390
 worker_thread+0xa63/0x1210 kernel/workqueue.c:2537
 kthread+0x270/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: rcu_preempt kthread starved for 10492 jiffies! g142685 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:26552 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5307 [inline]
 __schedule+0x173b/0x4630 kernel/sched/core.c:6625
 schedule+0xc3/0x180 kernel/sched/core.c:6701
 schedule_timeout+0x1bd/0x310 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x2c6/0x1010 kernel/rcu/tree.c:1608
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1807
 kthread+0x270/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 29136 Comm: syz-executor.4 Not tainted 6.3.0-rc4-syzkaller-00034-gfcd476ea6a88 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/17/2023
RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline]
RIP: 0010:smp_call_function_many_cond+0x23e4/0x3600 kernel/smp.c:987
Code: 0f b6 04 03 84 c0 75 7f 45 8b 37 44 89 f6 83 e6 01 31 ff e8 5e 0f 0b 00 41 83 e6 01 4d 89 e6 75 07 e8 a0 0b 0b 00 eb 40 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 10 41 f7 07 01
RSP: 0018:ffffc90003807200 EFLAGS: 00000293
RAX: ffffffff817f4774 RBX: 1ffff11017328561 RCX: ffff888018801d40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003807600 R08: ffffffff817f4742 R09: fffffbfff205c63f
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b983cfc0
R13: 0000000000000001 R14: ffff8880b983cfc0 R15: ffff8880b9942b08
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002027d000 CR3: 000000000cd30000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1155
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:924 [inline]
 flush_tlb_mm_range+0x332/0x530 arch/x86/mm/tlb.c:1010
 tlb_flush arch/x86/include/asm/tlb.h:20 [inline]
 tlb_flush_mmu_tlbonly+0x1b3/0x420 include/asm-generic/tlb.h:458
 tlb_flush_mmu+0x2c/0x210 mm/mmu_gather.c:298
 tlb_finish_mmu+0xd4/0x1f0 mm/mmu_gather.c:391
 exit_mmap+0x2c9/0x850 mm/mmap.c:3042
 __mmput+0x115/0x3c0 kernel/fork.c:1204
 exit_mm+0x227/0x310 kernel/exit.c:563
 do_exit+0x612/0x2290 kernel/exit.c:856
 do_group_exit+0x206/0x2c0 kernel/exit.c:1019
 get_signal+0x1701/0x17e0 kernel/signal.c:2859
 arch_do_signal_or_restart+0x91/0x670 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fdc12c8c0f9
Code: Unable to access opcode bytes at 0x7fdc12c8c0cf.
RSP: 002b:00007fdc139a1218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fdc12dabf88 RCX: 00007fdc12c8c0f9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdc12dabf88
RBP: 00007fdc12dabf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdc12dabf8c
R13: 00007ffcf876254f R14: 00007fdc139a1300 R15: 0000000000022000
 </TASK>