------------[ cut here ]------------
WARNING: CPU: 0 PID: 20185 at kernel/rcu/tree_stall.h:1050 rcu_check_gp_start_stall+0x2e4/0x470
Modules linked in:
CPU: 0 UID: 0 PID: 20185 Comm: syz.5.4147 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:rcu_check_gp_start_stall+0x2e4/0x470
Code: ff ff 48 c7 c7 20 64 b0 99 be 04 00 00 00 e8 d3 ad 7c 00 4c 89 f7 b8 01 00 00 00 87 05 55 5b 09 18 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 40 f4 13 8e 74 47 48 c7 c0 60 e3 a3 8f 48 c1 e8
RSP: 0018:ffffc90000007bb8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000a02 RCX: ffffffff81a708bd
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e13f440
RBP: ffffc90000007e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff3360c84 R12: 0000000000002904
R13: 1ffff110096075f2 R14: ffffffff8e13f440 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8612000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30e16ff8 CR3: 000000000df36000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000082 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_core+0x5fa/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:__sanitizer_cov_trace_pc+0x11/0x70
Code: 5b e9 13 21 59 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 e0 a0 92 <65> 8b 15 b8 1e e1 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc9000777f578 EFLAGS: 00000202
RAX: ffffffff81b4621b RBX: 1ffff11026cc7f61 RCX: ffff888124199cc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000777f700 R08: ffffffff8fa3b237 R09: 1ffffffff1f47646
R10: dffffc0000000000 R11: fffffbfff1f47647 R12: ffff88813663fb08
R13: dffffc0000000000 R14: ffff88804b03b1c0 R15: 0000000000000001
 smp_call_function_many_cond+0xd4b/0x12d0
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 tlb_flush_mmu+0x1a7/0x680
 tlb_finish_mmu+0xc3/0x1d0
 free_ldt_pgtables+0x17b/0x320
 exit_mmap+0x17c/0xb50
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff67bd8ec29
Code: Unable to access opcode bytes at 0x7ff67bd8ebff.
RSP: 002b:00007ffe0d9e0d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff67bd8ec29
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe0d9e0d9c R08: 0000001e0d9e0e2f R09: 00000000000927c0
R10: 000000000000d89c R11: 0000000000000246 R12: 0000000000000293
R13: 00000000000927c0 R14: 000000000008edb0 R15: 00007ffe0d9e0df0
 </TASK>
