* [syzbot] [mm?] kernel BUG in page_table_check_set
@ 2025-08-22 4:16 syzbot
2025-08-22 5:32 ` Dev Jain
2025-08-23 1:16 ` Andrew Morton
0 siblings, 2 replies; 8+ messages in thread
From: syzbot @ 2025-08-22 4:16 UTC (permalink / raw)
To: akpm, linux-kernel, linux-mm, pasha.tatashin, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=15f926f0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c5ac3d8b8abfcb
dashboard link: https://syzkaller.appspot.com/bug?extid=49a796ed2c9709652f1e
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15faa7a2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144143bc580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/18a2e4bd0c4a/disk-8f5ae30d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3b5395881b25/vmlinux-8f5ae30d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e875f4e3b7ff/Image-8f5ae30d.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
------------[ cut here ]------------
kernel BUG at mm/page_table_check.c:118!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
Modules linked in:
CPU: 1 UID: 0 PID: 6740 Comm: syz.0.17 Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : page_table_check_set+0x584/0x590 mm/page_table_check.c:118
lr : page_table_check_set+0x584/0x590 mm/page_table_check.c:118
sp : ffff80009c9674c0
x29: ffff80009c9674d0 x28: ffff80008fae0000 x27: 0000000000000002
x26: ffff0000c079ca80 x25: 0000000000000001 x24: 0000000000000001
x23: ffff0000c079ca80 x22: 000000000012b950 x21: 0000000000000001
x20: 0000000000000003 x19: 1ffff00012eb65b0 x18: 0000000000000000
x17: 0000000000000000 x16: ffff800080528a28 x15: 0000000000000001
x14: 1fffe000180f3950 x13: 0000000000000000 x12: 0000000000000000
x11: ffff6000180f3951 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : ffff0000cdb05b80 x7 : ffff800080d16554 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080d15b5c
x2 : 0000000000000001 x1 : 0000000000000002 x0 : 0000000000000001
Call trace:
page_table_check_set+0x584/0x590 mm/page_table_check.c:118 (P)
__page_table_check_ptes_set+0x2a8/0x2e0 mm/page_table_check.c:209
page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
__set_ptes_anysz arch/arm64/include/asm/pgtable.h:709 [inline]
__set_ptes+0x4a0/0x504 arch/arm64/include/asm/pgtable.h:741
contpte_set_ptes+0x120/0x188 arch/arm64/mm/contpte.c:464
set_ptes arch/arm64/include/asm/pgtable.h:1794 [inline]
modify_prot_commit_ptes+0x4e4/0x694 arch/arm64/mm/mmu.c:1556
prot_commit_flush_ptes mm/mprotect.c:197 [inline]
commit_anon_folio_batch mm/mprotect.c:246 [inline]
set_write_prot_commit_flush_ptes mm/mprotect.c:273 [inline]
change_pte_range mm/mprotect.c:354 [inline]
change_pmd_range mm/mprotect.c:570 [inline]
change_pud_range mm/mprotect.c:633 [inline]
change_p4d_range mm/mprotect.c:659 [inline]
change_protection_range mm/mprotect.c:687 [inline]
change_protection+0x1e84/0x3ff0 mm/mprotect.c:721
mprotect_fixup+0x504/0x744 mm/mprotect.c:837
do_mprotect_pkey+0x864/0xb30 mm/mprotect.c:993
__do_sys_mprotect mm/mprotect.c:1014 [inline]
__se_sys_mprotect mm/mprotect.c:1011 [inline]
__arm64_sys_mprotect+0x80/0x98 mm/mprotect.c:1011
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
Code: d4210000 97e865fd d4210000 97e865fb (d4210000)
---[ end trace 0000000000000000 ]---
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] [mm?] kernel BUG in page_table_check_set
2025-08-22 4:16 [syzbot] [mm?] kernel BUG in page_table_check_set syzbot
@ 2025-08-22 5:32 ` Dev Jain
2025-08-22 6:23 ` syzbot
2025-08-23 1:16 ` Andrew Morton
1 sibling, 1 reply; 8+ messages in thread
From: Dev Jain @ 2025-08-22 5:32 UTC (permalink / raw)
To: syzbot, akpm, linux-kernel, linux-mm, pasha.tatashin,
syzkaller-bugs
On 22/08/25 9:46 am, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1
> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> console output: https://syzkaller.appspot.com/x/log.txt?x=15f926f0580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=8c5ac3d8b8abfcb
> dashboard link: https://syzkaller.appspot.com/bug?extid=49a796ed2c9709652f1e
> compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
> userspace arch: arm64
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15faa7a2580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144143bc580000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/18a2e4bd0c4a/disk-8f5ae30d.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/3b5395881b25/vmlinux-8f5ae30d.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/e875f4e3b7ff/Image-8f5ae30d.gz.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
>
> ------------[ cut here ]------------
> kernel BUG at mm/page_table_check.c:118!
> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
> Modules linked in:
> CPU: 1 UID: 0 PID: 6740 Comm: syz.0.17 Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
> pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
> pc : page_table_check_set+0x584/0x590 mm/page_table_check.c:118
> lr : page_table_check_set+0x584/0x590 mm/page_table_check.c:118
> sp : ffff80009c9674c0
> x29: ffff80009c9674d0 x28: ffff80008fae0000 x27: 0000000000000002
> x26: ffff0000c079ca80 x25: 0000000000000001 x24: 0000000000000001
> x23: ffff0000c079ca80 x22: 000000000012b950 x21: 0000000000000001
> x20: 0000000000000003 x19: 1ffff00012eb65b0 x18: 0000000000000000
> x17: 0000000000000000 x16: ffff800080528a28 x15: 0000000000000001
> x14: 1fffe000180f3950 x13: 0000000000000000 x12: 0000000000000000
> x11: ffff6000180f3951 x10: 0000000000ff0100 x9 : 0000000000000000
> x8 : ffff0000cdb05b80 x7 : ffff800080d16554 x6 : 0000000000000000
> x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080d15b5c
> x2 : 0000000000000001 x1 : 0000000000000002 x0 : 0000000000000001
> Call trace:
> page_table_check_set+0x584/0x590 mm/page_table_check.c:118 (P)
> __page_table_check_ptes_set+0x2a8/0x2e0 mm/page_table_check.c:209
> page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
> __set_ptes_anysz arch/arm64/include/asm/pgtable.h:709 [inline]
> __set_ptes+0x4a0/0x504 arch/arm64/include/asm/pgtable.h:741
> contpte_set_ptes+0x120/0x188 arch/arm64/mm/contpte.c:464
> set_ptes arch/arm64/include/asm/pgtable.h:1794 [inline]
> modify_prot_commit_ptes+0x4e4/0x694 arch/arm64/mm/mmu.c:1556
> prot_commit_flush_ptes mm/mprotect.c:197 [inline]
> commit_anon_folio_batch mm/mprotect.c:246 [inline]
> set_write_prot_commit_flush_ptes mm/mprotect.c:273 [inline]
> change_pte_range mm/mprotect.c:354 [inline]
> change_pmd_range mm/mprotect.c:570 [inline]
> change_pud_range mm/mprotect.c:633 [inline]
> change_p4d_range mm/mprotect.c:659 [inline]
> change_protection_range mm/mprotect.c:687 [inline]
> change_protection+0x1e84/0x3ff0 mm/mprotect.c:721
> mprotect_fixup+0x504/0x744 mm/mprotect.c:837
> do_mprotect_pkey+0x864/0xb30 mm/mprotect.c:993
> __do_sys_mprotect mm/mprotect.c:1014 [inline]
> __se_sys_mprotect mm/mprotect.c:1011 [inline]
> __arm64_sys_mprotect+0x80/0x98 mm/mprotect.c:1011
> __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
> invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
> el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
> do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
> el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
> el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
> el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
> Code: d4210000 97e865fd d4210000 97e865fb (d4210000)
> ---[ end trace 0000000000000000 ]---
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git cf1b80dc31a1137b8b4568c138b453bf7453204a
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] [mm?] kernel BUG in page_table_check_set
2025-08-22 5:32 ` Dev Jain
@ 2025-08-22 6:23 ` syzbot
0 siblings, 0 replies; 8+ messages in thread
From: syzbot @ 2025-08-22 6:23 UTC (permalink / raw)
To: akpm, dev.jain, linux-kernel, linux-mm, pasha.tatashin,
syzkaller-bugs
Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
Tested-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
Tested on:
commit: cf1b80dc mm: pass page directly instead of using folio..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=116576f0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=dd02560acf543b19
dashboard link: https://syzkaller.appspot.com/bug?extid=49a796ed2c9709652f1e
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64
Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] [mm?] kernel BUG in page_table_check_set
2025-08-22 4:16 [syzbot] [mm?] kernel BUG in page_table_check_set syzbot
2025-08-22 5:32 ` Dev Jain
@ 2025-08-23 1:16 ` Andrew Morton
2025-08-23 1:45 ` Pasha Tatashin
2025-08-23 3:23 ` Ritesh Harjani
1 sibling, 2 replies; 8+ messages in thread
From: Andrew Morton @ 2025-08-23 1:16 UTC (permalink / raw)
To: syzbot
Cc: linux-kernel, linux-mm, pasha.tatashin, syzkaller-bugs,
Andrew Donnellan
On Thu, 21 Aug 2025 21:16:32 -0700 syzbot <syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com> wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1
> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> console output: https://syzkaller.appspot.com/x/log.txt?x=15f926f0580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=8c5ac3d8b8abfcb
> dashboard link: https://syzkaller.appspot.com/bug?extid=49a796ed2c9709652f1e
> compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
> userspace arch: arm64
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15faa7a2580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144143bc580000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/18a2e4bd0c4a/disk-8f5ae30d.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/3b5395881b25/vmlinux-8f5ae30d.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/e875f4e3b7ff/Image-8f5ae30d.gz.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
>
> ------------[ cut here ]------------
> kernel BUG at mm/page_table_check.c:118!
Thanks.
Presumably due to the series "Support page table check on PowerPC".
Andrew, could you please take a look?
The series has been in mm.git for a week so I guess the impact of this
is small. I won't drop it at this time, but prompt attention would be
appreciated.
> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
> Modules linked in:
> CPU: 1 UID: 0 PID: 6740 Comm: syz.0.17 Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
> pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
> pc : page_table_check_set+0x584/0x590 mm/page_table_check.c:118
> lr : page_table_check_set+0x584/0x590 mm/page_table_check.c:118
> sp : ffff80009c9674c0
> x29: ffff80009c9674d0 x28: ffff80008fae0000 x27: 0000000000000002
> x26: ffff0000c079ca80 x25: 0000000000000001 x24: 0000000000000001
> x23: ffff0000c079ca80 x22: 000000000012b950 x21: 0000000000000001
> x20: 0000000000000003 x19: 1ffff00012eb65b0 x18: 0000000000000000
> x17: 0000000000000000 x16: ffff800080528a28 x15: 0000000000000001
> x14: 1fffe000180f3950 x13: 0000000000000000 x12: 0000000000000000
> x11: ffff6000180f3951 x10: 0000000000ff0100 x9 : 0000000000000000
> x8 : ffff0000cdb05b80 x7 : ffff800080d16554 x6 : 0000000000000000
> x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080d15b5c
> x2 : 0000000000000001 x1 : 0000000000000002 x0 : 0000000000000001
> Call trace:
> page_table_check_set+0x584/0x590 mm/page_table_check.c:118 (P)
> __page_table_check_ptes_set+0x2a8/0x2e0 mm/page_table_check.c:209
> page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
> __set_ptes_anysz arch/arm64/include/asm/pgtable.h:709 [inline]
> __set_ptes+0x4a0/0x504 arch/arm64/include/asm/pgtable.h:741
> contpte_set_ptes+0x120/0x188 arch/arm64/mm/contpte.c:464
> set_ptes arch/arm64/include/asm/pgtable.h:1794 [inline]
> modify_prot_commit_ptes+0x4e4/0x694 arch/arm64/mm/mmu.c:1556
> prot_commit_flush_ptes mm/mprotect.c:197 [inline]
> commit_anon_folio_batch mm/mprotect.c:246 [inline]
> set_write_prot_commit_flush_ptes mm/mprotect.c:273 [inline]
> change_pte_range mm/mprotect.c:354 [inline]
> change_pmd_range mm/mprotect.c:570 [inline]
> change_pud_range mm/mprotect.c:633 [inline]
> change_p4d_range mm/mprotect.c:659 [inline]
> change_protection_range mm/mprotect.c:687 [inline]
> change_protection+0x1e84/0x3ff0 mm/mprotect.c:721
> mprotect_fixup+0x504/0x744 mm/mprotect.c:837
> do_mprotect_pkey+0x864/0xb30 mm/mprotect.c:993
> __do_sys_mprotect mm/mprotect.c:1014 [inline]
> __se_sys_mprotect mm/mprotect.c:1011 [inline]
> __arm64_sys_mprotect+0x80/0x98 mm/mprotect.c:1011
> __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
> invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
> el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
> do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
> el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
> el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
> el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
> Code: d4210000 97e865fd d4210000 97e865fb (d4210000)
> ---[ end trace 0000000000000000 ]---
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] [mm?] kernel BUG in page_table_check_set
2025-08-23 1:16 ` Andrew Morton
@ 2025-08-23 1:45 ` Pasha Tatashin
2025-08-23 3:23 ` Ritesh Harjani
1 sibling, 0 replies; 8+ messages in thread
From: Pasha Tatashin @ 2025-08-23 1:45 UTC (permalink / raw)
To: Andrew Morton
Cc: syzbot, linux-kernel, linux-mm, syzkaller-bugs, Andrew Donnellan
On Sat, Aug 23, 2025 at 1:16 AM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Thu, 21 Aug 2025 21:16:32 -0700 syzbot <syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com> wrote:
>
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1
> > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> > console output: https://syzkaller.appspot.com/x/log.txt?x=15f926f0580000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=8c5ac3d8b8abfcb
> > dashboard link: https://syzkaller.appspot.com/bug?extid=49a796ed2c9709652f1e
> > compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
> > userspace arch: arm64
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15faa7a2580000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144143bc580000
> >
> > Downloadable assets:
> > disk image: https://storage.googleapis.com/syzbot-assets/18a2e4bd0c4a/disk-8f5ae30d.raw.xz
> > vmlinux: https://storage.googleapis.com/syzbot-assets/3b5395881b25/vmlinux-8f5ae30d.xz
> > kernel image: https://storage.googleapis.com/syzbot-assets/e875f4e3b7ff/Image-8f5ae30d.gz.xz
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
> >
> > ------------[ cut here ]------------
> > kernel BUG at mm/page_table_check.c:118!
>
> Thanks.
>
> Presumably due to the series "Support page table check on PowerPC".
> Andrew, could you please take a look?
>
> The series has been in mm.git for a week so I guess the impact of this
> is small. I won't drop it at this time, but prompt attention would be
> appreciated.
page_table_check_set()
BUG_ON(atomic_inc_return(&ptc->anon_map_count) > 1 && rw);
This code triggers a BUG_ON if we attempt to set a new PTE in a user
page table with RW permission for an anonymous page that is already
mapped elsewhere. Anonymous pages can only be shared with RO
permissions for COW; otherwise, it can't be shared.
Pasha
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] [mm?] kernel BUG in page_table_check_set
2025-08-23 1:16 ` Andrew Morton
2025-08-23 1:45 ` Pasha Tatashin
@ 2025-08-23 3:23 ` Ritesh Harjani
2025-08-23 17:07 ` Andrew Morton
1 sibling, 1 reply; 8+ messages in thread
From: Ritesh Harjani @ 2025-08-23 3:23 UTC (permalink / raw)
To: Andrew Morton, syzbot
Cc: linux-kernel, linux-mm, pasha.tatashin, syzkaller-bugs,
Andrew Donnellan
Andrew Morton <akpm@linux-foundation.org> writes:
> On Thu, 21 Aug 2025 21:16:32 -0700 syzbot <syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com> wrote:
>
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1
>> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
>> console output: https://syzkaller.appspot.com/x/log.txt?x=15f926f0580000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=8c5ac3d8b8abfcb
>> dashboard link: https://syzkaller.appspot.com/bug?extid=49a796ed2c9709652f1e
>> compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
>> userspace arch: arm64
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15faa7a2580000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144143bc580000
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/18a2e4bd0c4a/disk-8f5ae30d.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/3b5395881b25/vmlinux-8f5ae30d.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/e875f4e3b7ff/Image-8f5ae30d.gz.xz
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
>>
>> ------------[ cut here ]------------
>> kernel BUG at mm/page_table_check.c:118!
>
> Thanks.
>
> Presumably due to the series "Support page table check on PowerPC".
The syzbot triggered this on:
HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
This tree does not have "Support page table check on PowerPC", correct?
Also, I guess Dev's change fixes this reported problem which could happen in
this path: commit_anon_folio_batch() -> change_pte_range() ...
[1]: https://lore.kernel.org/all/20250812060124.C9344C4CEF0@smtp.kernel.org/
[2]: https://lore.kernel.org/all/68a80cc6.050a0220.3809a8.0002.GAE@google.com/
-ritesh
> Andrew, could you please take a look?
>
> The series has been in mm.git for a week so I guess the impact of this
> is small. I won't drop it at this time, but prompt attention would be
> appreciated.
>
>> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
>> Modules linked in:
>> CPU: 1 UID: 0 PID: 6740 Comm: syz.0.17 Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
>> pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
>> pc : page_table_check_set+0x584/0x590 mm/page_table_check.c:118
>> lr : page_table_check_set+0x584/0x590 mm/page_table_check.c:118
>> sp : ffff80009c9674c0
>> x29: ffff80009c9674d0 x28: ffff80008fae0000 x27: 0000000000000002
>> x26: ffff0000c079ca80 x25: 0000000000000001 x24: 0000000000000001
>> x23: ffff0000c079ca80 x22: 000000000012b950 x21: 0000000000000001
>> x20: 0000000000000003 x19: 1ffff00012eb65b0 x18: 0000000000000000
>> x17: 0000000000000000 x16: ffff800080528a28 x15: 0000000000000001
>> x14: 1fffe000180f3950 x13: 0000000000000000 x12: 0000000000000000
>> x11: ffff6000180f3951 x10: 0000000000ff0100 x9 : 0000000000000000
>> x8 : ffff0000cdb05b80 x7 : ffff800080d16554 x6 : 0000000000000000
>> x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080d15b5c
>> x2 : 0000000000000001 x1 : 0000000000000002 x0 : 0000000000000001
>> Call trace:
>> page_table_check_set+0x584/0x590 mm/page_table_check.c:118 (P)
>> __page_table_check_ptes_set+0x2a8/0x2e0 mm/page_table_check.c:209
>> page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
>> __set_ptes_anysz arch/arm64/include/asm/pgtable.h:709 [inline]
>> __set_ptes+0x4a0/0x504 arch/arm64/include/asm/pgtable.h:741
>> contpte_set_ptes+0x120/0x188 arch/arm64/mm/contpte.c:464
>> set_ptes arch/arm64/include/asm/pgtable.h:1794 [inline]
>> modify_prot_commit_ptes+0x4e4/0x694 arch/arm64/mm/mmu.c:1556
>> prot_commit_flush_ptes mm/mprotect.c:197 [inline]
>> commit_anon_folio_batch mm/mprotect.c:246 [inline]
>> set_write_prot_commit_flush_ptes mm/mprotect.c:273 [inline]
>> change_pte_range mm/mprotect.c:354 [inline]
>> change_pmd_range mm/mprotect.c:570 [inline]
>> change_pud_range mm/mprotect.c:633 [inline]
>> change_p4d_range mm/mprotect.c:659 [inline]
>> change_protection_range mm/mprotect.c:687 [inline]
>> change_protection+0x1e84/0x3ff0 mm/mprotect.c:721
>> mprotect_fixup+0x504/0x744 mm/mprotect.c:837
>> do_mprotect_pkey+0x864/0xb30 mm/mprotect.c:993
>> __do_sys_mprotect mm/mprotect.c:1014 [inline]
>> __se_sys_mprotect mm/mprotect.c:1011 [inline]
>> __arm64_sys_mprotect+0x80/0x98 mm/mprotect.c:1011
>> __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
>> invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
>> el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
>> do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
>> el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
>> el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
>> el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
>> Code: d4210000 97e865fd d4210000 97e865fb (d4210000)
>> ---[ end trace 0000000000000000 ]---
>>
>>
>> ---
>> This report is generated by a bot. It may contain errors.
>> See https://goo.gl/tpsmEJ for more information about syzbot.
>> syzbot engineers can be reached at syzkaller@googlegroups.com.
>>
>> syzbot will keep track of this issue. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>>
>> If the report is already addressed, let syzbot know by replying with:
>> #syz fix: exact-commit-title
>>
>> If you want syzbot to run the reproducer, reply with:
>> #syz test: git://repo/address.git branch-or-commit-hash
>> If you attach or paste a git patch, syzbot will apply it before testing.
>>
>> If you want to overwrite report's subsystems, reply with:
>> #syz set subsystems: new-subsystem
>> (See the list of subsystem names on the web dashboard)
>>
>> If the report is a duplicate of another one, reply with:
>> #syz dup: exact-subject-of-another-report
>>
>> If you want to undo deduplication, reply with:
>> #syz undup
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] [mm?] kernel BUG in page_table_check_set
2025-08-23 3:23 ` Ritesh Harjani
@ 2025-08-23 17:07 ` Andrew Morton
2025-08-23 18:18 ` syzbot
0 siblings, 1 reply; 8+ messages in thread
From: Andrew Morton @ 2025-08-23 17:07 UTC (permalink / raw)
To: Ritesh Harjani
Cc: syzbot, linux-kernel, linux-mm, pasha.tatashin, syzkaller-bugs,
Andrew Donnellan
On Sat, 23 Aug 2025 08:53:28 +0530 Ritesh Harjani (IBM) <ritesh.list@gmail.com> wrote:
> Andrew Morton <akpm@linux-foundation.org> writes:
>
> > On Thu, 21 Aug 2025 21:16:32 -0700 syzbot <syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com> wrote:
> >
> >> Hello,
> >>
> >> syzbot found the following issue on:
> >>
> >> HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1
> >> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> >> console output: https://syzkaller.appspot.com/x/log.txt?x=15f926f0580000
> >> kernel config: https://syzkaller.appspot.com/x/.config?x=8c5ac3d8b8abfcb
> >> dashboard link: https://syzkaller.appspot.com/bug?extid=49a796ed2c9709652f1e
> >> compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
> >> userspace arch: arm64
> >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15faa7a2580000
> >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144143bc580000
> >>
> >> Downloadable assets:
> >> disk image: https://storage.googleapis.com/syzbot-assets/18a2e4bd0c4a/disk-8f5ae30d.raw.xz
> >> vmlinux: https://storage.googleapis.com/syzbot-assets/3b5395881b25/vmlinux-8f5ae30d.xz
> >> kernel image: https://storage.googleapis.com/syzbot-assets/e875f4e3b7ff/Image-8f5ae30d.gz.xz
> >>
> >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> >> Reported-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
> >>
> >> ------------[ cut here ]------------
> >> kernel BUG at mm/page_table_check.c:118!
> >
> > Thanks.
> >
> > Presumably due to the series "Support page table check on PowerPC".
>
> The syzbot triggered this on:
> HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1
> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
>
> This tree does not have "Support page table check on PowerPC", correct?
Yep, sorry.
> Also, I guess Dev's change fixes this reported problem which could happen in
> this path: commit_anon_folio_batch() -> change_pte_range() ...
>
> [1]: https://lore.kernel.org/all/20250812060124.C9344C4CEF0@smtp.kernel.org/
> [2]: https://lore.kernel.org/all/68a80cc6.050a0220.3809a8.0002.GAE@google.com/
Cool. Dev's fix is in 6.17-rc2 as cf1b80dc31a1.
#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c17b750b3ad9
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] [mm?] kernel BUG in page_table_check_set
2025-08-23 17:07 ` Andrew Morton
@ 2025-08-23 18:18 ` syzbot
0 siblings, 0 replies; 8+ messages in thread
From: syzbot @ 2025-08-23 18:18 UTC (permalink / raw)
To: ajd, akpm, linux-kernel, linux-mm, pasha.tatashin, ritesh.list,
syzkaller-bugs
Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
Tested-by: syzbot+49a796ed2c9709652f1e@syzkaller.appspotmail.com
Tested on:
commit: c17b750b Linux 6.17-rc2
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1058a7bc580000
kernel config: https://syzkaller.appspot.com/x/.config?x=34aa432f9050e15d
dashboard link: https://syzkaller.appspot.com/bug?extid=49a796ed2c9709652f1e
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64
Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2025-08-23 18:18 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-08-22 4:16 [syzbot] [mm?] kernel BUG in page_table_check_set syzbot
2025-08-22 5:32 ` Dev Jain
2025-08-22 6:23 ` syzbot
2025-08-23 1:16 ` Andrew Morton
2025-08-23 1:45 ` Pasha Tatashin
2025-08-23 3:23 ` Ritesh Harjani
2025-08-23 17:07 ` Andrew Morton
2025-08-23 18:18 ` syzbot
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