Re: [syzbot] [mm?] WARNING in try_to_migrate_one (3)

[syzbot <syzbot+63859a31071a369082b1@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in try_to_migrate_one

 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1277
 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1536
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584
 __vm_munmap+0x23b/0x3d0 mm/vma.c:3155
 __do_sys_munmap mm/mmap.c:1080 [inline]
 __se_sys_munmap mm/mmap.c:1077 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1077
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
------------[ cut here ]------------
WARNING: CPU: 1 PID: 6665 at mm/rmap.c:2460 try_to_migrate_one+0x20a9/0x3cb0 mm/rmap.c:2459
Modules linked in:
CPU: 1 UID: 0 PID: 6665 Comm: syz.0.17 Not tainted 6.16.0-syzkaller-12288-g2b38afce25c4-dirty #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:try_to_migrate_one+0x20a9/0x3cb0 mm/rmap.c:2459
Code: c7 c7 a0 79 96 8b e8 36 cd 71 ff 90 0f 0b 90 90 e9 a8 f8 ff ff e8 a7 2e ae ff 4c 89 ff 48 c7 c6 c0 78 96 8b e8 f8 7e 16 ff 90 <0f> 0b 90 e9 22 ef ff ff e8 8a 2e ae ff 49 ff cf e9 e5 ef ff ff e8
RSP: 0018:ffffc90002f87120 EFLAGS: 00010246
RAX: 1f9183d47663e300 RBX: 0000000000000001 RCX: 1f9183d47663e300
RDX: 0000000000000003 RSI: ffffffff8dba5fbd RDI: ffff88802540da00
RBP: ffffc90002f87370 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1ec R12: ffffea0001ad8018
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffea0001ad8000
FS:  00007f6cc346c6c0(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056399b4b5008 CR3: 0000000074e12000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rmap_walk_anon+0x553/0x730 mm/rmap.c:2851
 rmap_walk_locked mm/rmap.c:2967 [inline]
 try_to_migrate+0x3f5/0x670 mm/rmap.c:2628
 unmap_folio+0x191/0x1f0 mm/huge_memory.c:3137
 __folio_split+0x90d/0x1c60 mm/huge_memory.c:3711
 try_split_folio+0x13f/0x310 mm/migrate.c:1550
 migrate_pages_batch+0x653/0x3620 mm/migrate.c:1819
 migrate_pages_sync mm/migrate.c:1974 [inline]
 migrate_pages+0x1bcc/0x2930 mm/migrate.c:2083
 do_mbind mm/mempolicy.c:1539 [inline]
 kernel_mbind mm/mempolicy.c:1682 [inline]
 __do_sys_mbind mm/mempolicy.c:1756 [inline]
 __se_sys_mbind+0xa3e/0xc30 mm/mempolicy.c:1752
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cc258ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6cc346c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 00007f6cc27b5fa0 RCX: 00007f6cc258ebe9
RDX: 0000000000000001 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f6cc2611e19 R08: 0000000000000000 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6cc27b6038 R14: 00007f6cc27b5fa0 R15: 00007ffd706df1a8
 </TASK>


Tested on:

commit:         2b38afce Merge tag 'turbostat-2025.09.09' of git://git..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16b8f2f0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2ae1da3a7f4a6ba4
dashboard link: https://syzkaller.appspot.com/bug?extid=63859a31071a369082b1
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13f3fea2580000