------------[ cut here ]------------
kernel BUG at [] mm/page_table_check.c:142!
Kernel BUG [#1]
Modules linked in:
CPU: 1 UID: 0 PID: 4122 Comm: syz.0.86 Not tainted syzkaller #0 PREEMPT 
Hardware name: riscv-virtio,qemu (DT)
epc : __page_table_check_zero+0x370/0x532 mm/page_table_check.c:142
 ra : __page_table_check_zero+0x370/0x532 mm/page_table_check.c:142
epc : ffffffff80ca2cf4 ra : ffffffff80ca2cf4 sp : ffff8f800ba76ab0
 gp : ffffffff8a4c0280 tp : ffffaf8016ee9a80 t0 : ffff8f800ba76a60
 t1 : fffff5ef027a9409 t2 : ffff8f800ba76da0 s0 : ffff8f800ba76b20
 s1 : ffffaf8013d4a048 a0 : 0000000000000005 a1 : 0000000000000000
 a2 : 0000000000000002 a3 : ffffffff80ca2cf4 a4 : 0000000000000000
 a5 : ffffaf8016eeaa80 a6 : 0000000000000003 a7 : ffffaf8013d4a04b
 s2 : 0000000000000001 s3 : 0000000000000000 s4 : ffffaf8013d4a000
 s5 : dfffffff00000000 s6 : 0000000000000200 s7 : 00000000000b4200
 s8 : ffffffff88c66940 s9 : 0000000000007fff s10: fffffffef14bbfa4
 s11: ffffffff8a5dfd20 t3 : 0000000000000001 t4 : fffff5ef027a9409
 t5 : fffff5ef027a940a t6 : 0000000000000002 ssp : 0000000000000000
status: 0000000200000120 badaddr: ffffffff80ca2cf4 cause: 0000000000000003
[<ffffffff80ca2cf4>] __page_table_check_zero+0x370/0x532 mm/page_table_check.c:142
[<ffffffff80b2002c>] page_table_check_free include/linux/page_table_check.h:46 [inline]
[<ffffffff80b2002c>] __free_pages_prepare mm/page_alloc.c:1407 [inline]
[<ffffffff80b2002c>] free_unref_folios+0xb72/0x1b80 mm/page_alloc.c:3011
[<ffffffff8094e370>] folios_put_refs+0x46c/0x7c6 mm/swap.c:1057
[<ffffffff80b70338>] free_pages_and_swap_cache+0x22e/0x3be mm/swap_state.c:586
[<ffffffff80a91e2c>] __tlb_batch_free_encoded_pages+0xe2/0x25a mm/mmu_gather.c:138
[<ffffffff80a9385c>] tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
[<ffffffff80a9385c>] tlb_flush_mmu_free mm/mmu_gather.c:417 [inline]
[<ffffffff80a9385c>] tlb_flush_mmu+0xdc/0x5f8 mm/mmu_gather.c:424
[<ffffffff80a55470>] zap_pte_range mm/memory.c:1973 [inline]
[<ffffffff80a55470>] zap_pmd_range mm/memory.c:2020 [inline]
[<ffffffff80a55470>] zap_pud_range mm/memory.c:2048 [inline]
[<ffffffff80a55470>] zap_p4d_range mm/memory.c:2069 [inline]
[<ffffffff80a55470>] __zap_vma_range+0x1490/0x44e4 mm/memory.c:2109
[<ffffffff80a59ab0>] unmap_vmas+0x244/0x518 mm/memory.c:2178
[<ffffffff80a8e1ba>] exit_mmap+0x1f8/0xc9e mm/mmap.c:1300
[<ffffffff801465ba>] __mmput+0x106/0x3d0 kernel/fork.c:1193
[<ffffffff801468f8>] mmput+0x74/0x88 kernel/fork.c:1216
[<ffffffff80168ec2>] exit_mm kernel/exit.c:614 [inline]
[<ffffffff80168ec2>] do_exit+0x80a/0x297a kernel/exit.c:996
[<ffffffff8016b55e>] do_group_exit+0xca/0x258 kernel/exit.c:1151
[<ffffffff801a4a1a>] get_signal+0x1f58/0x2224 kernel/signal.c:3046
[<ffffffff80075026>] arch_do_signal_or_restart+0x648/0x1e06 arch/riscv/kernel/signal.c:534
[<ffffffff803dc94a>] __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
[<ffffffff803dc94a>] exit_to_user_mode_loop+0x92/0xce8 kernel/entry/common.c:101
[<ffffffff865945d8>] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
[<ffffffff865945d8>] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
[<ffffffff865945d8>] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
[<ffffffff865945d8>] do_trap_ecall_u+0x52c/0x658 arch/riscv/kernel/traps.c:344
[<ffffffff865c0d08>] handle_exception+0x168/0x174 arch/riscv/kernel/entry.S:237
Code: 0ba0 854a c0ef ff6f 8a2a bf9d 2097 ff89 80e7 0a80 (9002) 2097 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	0ba0                	addi	s0,sp,472
   2:	854a                	mv	a0,s2
   4:	ff6fc0ef          	jal	0xffffffffffffc7fa
   8:	8a2a                	mv	s4,a0
   a:	bf9d                	j	0xffffffffffffff80
   c:	ff892097          	auipc	ra,0xff892
  10:	0a8080e7          	jalr	168(ra) # 0xff8920b4
* 14:	9002                	ebreak <-- trapping instruction
  16:	9720                	.short	0x2097