* [moderation/CI] Re: mm/khugepaged: collapse_file() cleanups
@ 2026-07-21 9:33 syzbot ci
2026-07-21 9:34 ` Aleksandr Nogikh
0 siblings, 1 reply; 2+ messages in thread
From: syzbot ci @ 2026-07-21 9:33 UTC (permalink / raw)
To: syzkaller-upstream-moderation; +Cc: syzbot
syzbot ci has tested the following series
[v1] mm/khugepaged: collapse_file() cleanups
https://lore.kernel.org/all/20260720142913.846902-1-pfalcato@suse.de
* [PATCH 1/8] mm/khugepaged: separate out windy folio logic from collapse_file
* [PATCH 2/8] mm/khugepaged: factor out page cache folio reading
* [PATCH 3/8] mm/khugepaged: factor out and simplify dirty/writeback handling
* [PATCH 4/8] mm/khugepaged: simplify prepare folio locking and exit paths
* [PATCH 5/8] mm/khugepaged: add kerneldoc to prepare_collapse_file_folio()
* [PATCH 6/8] mm/khugepaged: hoist isolation into collapse_isolate_folio()
* [PATCH 7/8] mm/khugepaged: hoist more code into collapse_isolate_folio()
* [PATCH 8/8] mm/khugepaged: fix and flesh out try_to_unmap_flush() comment
and found the following issue:
WARNING: bad unlock balance in collapse_scan_file
Full report is available here:
https://ci.syzbot.org/series/cc30d9d4-857a-45de-a8e8-b99f9346d0da
***
WARNING: bad unlock balance in collapse_scan_file
tree: mm-new
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git
base: c872b70f5d6c742ad34b8e838c92af81c8920b3e
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/e6e237b7-5a64-4732-bb37-4e62c3103d4a/config
syz repro: https://ci.syzbot.org/findings/51ee94c3-7fe6-47f6-81ed-a53cf51bb3f9/syz_repro
=====================================
WARNING: bad unlock balance detected!
syzkaller #0 Not tainted
-------------------------------------
syz.0.17/5868 is trying to release lock (&xa->xa_lock) at:
[<ffffffff823ac70f>] spin_unlock_irq include/linux/spinlock.h:402 [inline]
[<ffffffff823ac70f>] prepare_collapse_file_folio mm/khugepaged.c:2331 [inline]
[<ffffffff823ac70f>] collapse_file mm/khugepaged.c:2539 [inline]
[<ffffffff823ac70f>] collapse_scan_file+0x2cbf/0x4dc0 mm/khugepaged.c:2849
but there are no more locks to release!
other info that might help us debug this:
no locks held by syz.0.17/5868.
stack backtrace:
CPU: 0 UID: 0 PID: 5868 Comm: syz.0.17 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
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_unlock_imbalance_bug+0xdc/0xf0 kernel/locking/lockdep.c:5299
__lock_release kernel/locking/lockdep.c:5528 [inline]
lock_release+0x1fb/0x3c0 kernel/locking/lockdep.c:5912
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:185 [inline]
_raw_spin_unlock_irq+0x16/0x50 kernel/locking/spinlock.c:206
spin_unlock_irq include/linux/spinlock.h:402 [inline]
prepare_collapse_file_folio mm/khugepaged.c:2331 [inline]
collapse_file mm/khugepaged.c:2539 [inline]
collapse_scan_file+0x2cbf/0x4dc0 mm/khugepaged.c:2849
collapse_single_pmd+0x2b1/0x3da0 mm/khugepaged.c:2884
madvise_collapse+0x2cf/0x790 mm/khugepaged.c:3310
madvise_vma_behavior+0x115f/0x4170 mm/madvise.c:1363
madvise_walk_vmas+0x576/0xb00 mm/madvise.c:1712
madvise_do_behavior+0x385/0x540 mm/madvise.c:1907
do_madvise+0x327/0x3a0 mm/madvise.c:2005
__do_sys_madvise mm/madvise.c:2014 [inline]
__se_sys_madvise mm/madvise.c:2012 [inline]
__x64_sys_madvise+0xa6/0xc0 mm/madvise.c:2012
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb60079de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb6015c0028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007fb600a25fa0 RCX: 00007fb60079de99
RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000200000000000
RBP: 00007fb600833eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb600a26038 R14: 00007fb600a25fa0 R15: 00007ffc7db2f618
</TASK>
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
To test a patch for this bug, please reply with `#syz test`
(should be on a separate line).
The patch should be attached to the email.
Note: arguments like custom git repos and branches are not supported.
The email will later be sent to:
[akpm@linux-foundation.org baohua@kernel.org baolin.wang@linux.alibaba.com david@kernel.org dev.jain@arm.com lance.yang@linux.dev liam@infradead.org linux-kernel@vger.kernel.org linux-mm@kvack.org ljs@kernel.org npache@redhat.com pfalcato@suse.de ryan.roberts@arm.com usama.arif@linux.dev ziy@nvidia.com]
If the report looks fine to you, reply with:
#syz upstream
If the report is a false positive, reply with
#syz invalid
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [moderation/CI] Re: mm/khugepaged: collapse_file() cleanups
2026-07-21 9:33 [moderation/CI] Re: mm/khugepaged: collapse_file() cleanups syzbot ci
@ 2026-07-21 9:34 ` Aleksandr Nogikh
0 siblings, 0 replies; 2+ messages in thread
From: Aleksandr Nogikh @ 2026-07-21 9:34 UTC (permalink / raw)
To: syzbot ci; +Cc: syzkaller-upstream-moderation, syzbot
#syz upstream
On Tue, Jul 21, 2026 at 11:33 AM syzbot ci
<syzbot+cie7043cc98ea76fa1@syzkaller.appspotmail.com> wrote:
>
> syzbot ci has tested the following series
>
> [v1] mm/khugepaged: collapse_file() cleanups
> https://lore.kernel.org/all/20260720142913.846902-1-pfalcato@suse.de
> * [PATCH 1/8] mm/khugepaged: separate out windy folio logic from collapse_file
> * [PATCH 2/8] mm/khugepaged: factor out page cache folio reading
> * [PATCH 3/8] mm/khugepaged: factor out and simplify dirty/writeback handling
> * [PATCH 4/8] mm/khugepaged: simplify prepare folio locking and exit paths
> * [PATCH 5/8] mm/khugepaged: add kerneldoc to prepare_collapse_file_folio()
> * [PATCH 6/8] mm/khugepaged: hoist isolation into collapse_isolate_folio()
> * [PATCH 7/8] mm/khugepaged: hoist more code into collapse_isolate_folio()
> * [PATCH 8/8] mm/khugepaged: fix and flesh out try_to_unmap_flush() comment
>
> and found the following issue:
> WARNING: bad unlock balance in collapse_scan_file
>
> Full report is available here:
> https://ci.syzbot.org/series/cc30d9d4-857a-45de-a8e8-b99f9346d0da
>
> ***
>
> WARNING: bad unlock balance in collapse_scan_file
>
> tree: mm-new
> URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git
> base: c872b70f5d6c742ad34b8e838c92af81c8920b3e
> arch: amd64
> compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
> config: https://ci.syzbot.org/builds/e6e237b7-5a64-4732-bb37-4e62c3103d4a/config
> syz repro: https://ci.syzbot.org/findings/51ee94c3-7fe6-47f6-81ed-a53cf51bb3f9/syz_repro
>
> =====================================
> WARNING: bad unlock balance detected!
> syzkaller #0 Not tainted
> -------------------------------------
> syz.0.17/5868 is trying to release lock (&xa->xa_lock) at:
> [<ffffffff823ac70f>] spin_unlock_irq include/linux/spinlock.h:402 [inline]
> [<ffffffff823ac70f>] prepare_collapse_file_folio mm/khugepaged.c:2331 [inline]
> [<ffffffff823ac70f>] collapse_file mm/khugepaged.c:2539 [inline]
> [<ffffffff823ac70f>] collapse_scan_file+0x2cbf/0x4dc0 mm/khugepaged.c:2849
> but there are no more locks to release!
>
> other info that might help us debug this:
> no locks held by syz.0.17/5868.
>
> stack backtrace:
> CPU: 0 UID: 0 PID: 5868 Comm: syz.0.17 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
> Call Trace:
> <TASK>
> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
> print_unlock_imbalance_bug+0xdc/0xf0 kernel/locking/lockdep.c:5299
> __lock_release kernel/locking/lockdep.c:5528 [inline]
> lock_release+0x1fb/0x3c0 kernel/locking/lockdep.c:5912
> __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:185 [inline]
> _raw_spin_unlock_irq+0x16/0x50 kernel/locking/spinlock.c:206
> spin_unlock_irq include/linux/spinlock.h:402 [inline]
> prepare_collapse_file_folio mm/khugepaged.c:2331 [inline]
> collapse_file mm/khugepaged.c:2539 [inline]
> collapse_scan_file+0x2cbf/0x4dc0 mm/khugepaged.c:2849
> collapse_single_pmd+0x2b1/0x3da0 mm/khugepaged.c:2884
> madvise_collapse+0x2cf/0x790 mm/khugepaged.c:3310
> madvise_vma_behavior+0x115f/0x4170 mm/madvise.c:1363
> madvise_walk_vmas+0x576/0xb00 mm/madvise.c:1712
> madvise_do_behavior+0x385/0x540 mm/madvise.c:1907
> do_madvise+0x327/0x3a0 mm/madvise.c:2005
> __do_sys_madvise mm/madvise.c:2014 [inline]
> __se_sys_madvise mm/madvise.c:2012 [inline]
> __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:2012
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7fb60079de99
> Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007fb6015c0028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
> RAX: ffffffffffffffda RBX: 00007fb600a25fa0 RCX: 00007fb60079de99
> RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000200000000000
> RBP: 00007fb600833eaf R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007fb600a26038 R14: 00007fb600a25fa0 R15: 00007ffc7db2f618
> </TASK>
>
>
> ***
>
> If these findings have caused you to resend the series or submit a
> separate fix, please add the following tag to your commit message:
> Tested-by: syzbot@syzkaller.appspotmail.com
>
> ---
> This report is generated by a bot. It may contain errors.
> syzbot ci engineers can be reached at syzkaller@googlegroups.com.
>
> To test a patch for this bug, please reply with `#syz test`
> (should be on a separate line).
>
> The patch should be attached to the email.
> Note: arguments like custom git repos and branches are not supported.
>
> The email will later be sent to:
> [akpm@linux-foundation.org baohua@kernel.org baolin.wang@linux.alibaba.com david@kernel.org dev.jain@arm.com lance.yang@linux.dev liam@infradead.org linux-kernel@vger.kernel.org linux-mm@kvack.org ljs@kernel.org npache@redhat.com pfalcato@suse.de ryan.roberts@arm.com usama.arif@linux.dev ziy@nvidia.com]
>
> If the report looks fine to you, reply with:
> #syz upstream
>
> If the report is a false positive, reply with
> #syz invalid
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-07-21 9:34 UTC | newest]
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2026-07-21 9:33 [moderation/CI] Re: mm/khugepaged: collapse_file() cleanups syzbot ci
2026-07-21 9:34 ` Aleksandr Nogikh
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