kernel BUG in __page_table_check_zero (3)

Status: upstream: reported on 2026/02/18 21:59
Subsystems: mm
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+2b5fe617654be3d8848b@syzkaller.appspotmail.com
First crash: 204d, last: 9h49m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
87894511 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ kernel BUG in __page_table_check_zero (3) 2026/05/24 23:27 2026/05/24 23:27 2026/05/25 00:58 c69befb3
Discussions (4)
Title Replies (including bot) Last reply
[syzbot] Monthly mm report (Aug 2026) 0 (1) 2026/08/25 12:32
[syzbot] Monthly mm report (Jul 2026) 0 (1) 2026/07/25 04:32
[PATCH] mm/page_table_check: do not track special (PFN-mapped) PTEs 5 (5) 2026/06/17 11:07
[syzbot] [mm?] kernel BUG in __page_table_check_zero (3) 0 (1) 2026/02/18 21:59
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in __page_table_check_zero (2) mm -1 syz, C error done 32 666d 676d 0/29 auto-obsoleted due to no activity on 2025/01/19 02:16
linux-6.1 kernel BUG in __page_table_check_zero origin:lts-only -1 syz, C inconclusive 3 715d 1176d 0/3 upstream: reported C repro on 2023/06/18 21:38
upstream kernel BUG in __page_table_check_zero usb -1 syz, C error done 213 717d 1204d 28/29 fixed on 2024/10/22 13:24

Sample crash report:
------------[ cut here ]------------
kernel BUG at [] mm/page_table_check.c:142!
Kernel BUG [#1]
Modules linked in:
CPU: 0 UID: 0 PID: 5598 Comm: syz.0.531 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
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 : ffff8f8003917370
 gp : ffffffff8a4c0280 tp : ffffaf8015aacf80 t0 : ffff8f8003917320
 t1 : fffff5ef027abc09 t2 : ffffffff91898ba8 s0 : ffff8f80039173e0
 s1 : ffffaf8013d5e048 a0 : 0000000000000005 a1 : 0000000000000000
 a2 : 0000000000000002 a3 : ffffffff80ca2cf4 a4 : 0000000000000000
 a5 : ffffaf8015aadf80 a6 : 0000000000000003 a7 : ffffaf8013d5e04b
 s2 : 0000000000000001 s3 : 0000000000000000 s4 : ffffaf8013d5e000
 s5 : dfffffff00000000 s6 : 0000000000000200 s7 : 00000000000b4600
 s8 : ffffffff88c66940 s9 : 0000000000007fff s10: fffffffef14bbfa4
 s11: ffffffff8a5dfd20 t3 : 0000000000000001 t4 : fffff5ef027abc09
 t5 : fffff5ef027abc0a 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
[<ffffffff80b70382>] free_pages_and_swap_cache+0x278/0x3be mm/swap_state.c:589
[<ffffffff80a91e2c>] __tlb_batch_free_encoded_pages+0xe2/0x25a mm/mmu_gather.c:138
[<ffffffff80a94992>] tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
[<ffffffff80a94992>] tlb_flush_mmu_free mm/mmu_gather.c:417 [inline]
[<ffffffff80a94992>] tlb_flush_mmu mm/mmu_gather.c:424 [inline]
[<ffffffff80a94992>] tlb_finish_mmu+0x188/0x822 mm/mmu_gather.c:549
[<ffffffff80a8e3d6>] exit_mmap+0x414/0xc9e mm/mmap.c:1313
[<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
[<ffffffff8016b48a>] __do_sys_exit kernel/exit.c:1118 [inline]
[<ffffffff8016b48a>] __se_sys_exit kernel/exit.c:1116 [inline]
[<ffffffff8016b48a>] __riscv_sys_exit+0x48/0x52 kernel/exit.c:1116
[<ffffffff8007af94>] syscall_handler+0x92/0x114 arch/riscv/include/asm/syscall.h:112
[<ffffffff86594576>] do_trap_ecall_u+0x4ca/0x658 arch/riscv/kernel/traps.c:341
[<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

Crashes (319):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/07 04:17 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/09/06 19:12 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/31 03:20 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 2f52988a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/31 01:38 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 2f52988a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/30 23:58 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 2f52988a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/28 09:08 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 e2fa417d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/27 07:08 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 a2b77b9e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/24 04:28 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/24 01:21 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/23 23:57 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/23 11:57 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/23 05:31 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/23 01:08 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/22 21:39 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/08/22 20:38 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 77ae27fd98f3 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/07/26 21:46 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 76e885f2b89d 492bab15 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/07/20 06:39 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 93a278000821 72524a66 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/07/20 01:21 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 93a278000821 72524a66 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/07/20 00:53 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 93a278000821 72524a66 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/07/06 07:41 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 798246e5edfb fcece630 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/06/29 09:51 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 798246e5edfb fb92f11c .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/06/28 20:15 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 798246e5edfb fb92f11c .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/06/28 18:20 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 798246e5edfb fb92f11c .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/06/28 14:40 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 798246e5edfb fb92f11c .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/06/05 00:35 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 0ca1724b56af 197909be .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/06/01 07:35 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 0ca1724b56af 6b4a8443 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/06/01 00:07 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 0ca1724b56af 6b4a8443 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/05/26 07:44 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 0ca1724b56af c69befb3 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/05/26 07:43 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 0ca1724b56af c69befb3 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/05/24 12:25 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 0ca1724b56af c69befb3 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/27 19:52 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 0f700595 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/27 05:52 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/27 04:23 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/27 00:36 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 19:56 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 17:27 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 16:27 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 15:07 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 11:29 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 09:15 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 09:13 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 08:06 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 06:14 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/26 00:36 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/25 23:27 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/25 19:17 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/25 15:36 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/25 13:10 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/25 03:03 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/04/20 01:40 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 303e2802 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/03/09 08:50 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 18be4ca5cb4e 5cb44a80 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/02/16 13:32 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 18be4ca5cb4e 1e62d198 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
2026/02/14 21:51 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 18be4ca5cb4e 1e62d198 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 kernel BUG in __page_table_check_zero
* Struck through repros no longer work on HEAD.