[syzbot] [mm?] WARNING in move_pages

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ae00c445390b Add linux-next specific files for 20240212
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=126cddf4180000
kernel config: https://syzkaller.appspot.com/x/.config?x=4eb3a27eddb32a14
dashboard link: https://syzkaller.appspot.com/bug?extid=06ae923a4359a62d0bac
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16aa2720180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1437d320180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8b2a2d0b511f/disk-ae00c445.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a668a09c9d03/vmlinux-ae00c445.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4ad623928692/bzImage-ae00c445.xz

The issue was bisected to:

commit 31d97016c80a83daa4c938014c81282810a14773
Author: Lokesh Gidra <lokes...@google.com>
Date: Thu Feb 8 21:22:04 2024 +0000

userfaultfd: use per-vma locks in userfaultfd operations

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=170b3442180000
final oops: https://syzkaller.appspot.com/x/report.txt?x=148b3442180000
console output: https://syzkaller.appspot.com/x/log.txt?x=108b3442180000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+06ae92...@syzkaller.appspotmail.com
Fixes: 31d97016c80a ("userfaultfd: use per-vma locks in userfaultfd operations")

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5065 at mm/userfaultfd.c:1706 move_pages+0x438/0xff0 mm/userfaultfd.c:1706
Modules linked in:
CPU: 0 PID: 5065 Comm: syz-executor296 Not tainted 6.8.0-rc4-next-20240212-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:move_pages+0x438/0xff0 mm/userfaultfd.c:1706
Code: 0b 90 e9 d2 fe ff ff 90 0f 0b 90 31 ff 4c 89 e6 e8 6d 72 90 ff 4d 85 e4 74 2b e8 83 6d 90 ff e9 ba fd ff ff e8 79 6d 90 ff 90 <0f> 0b 90 45 31 e4 e9 a9 fd ff ff e8 68 6d 90 ff 45 31 e4 45 31 ff
RSP: 0018:ffffc9000345f640 EFLAGS: 00010293
RAX: ffffffff82036f37 RBX: 1ffff9200068bedc RCX: ffff88801fc41e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000345f770 R08: ffffffff82036e0e R09: 1ffffffff1f0cfa5
R10: dffffc0000000000 R11: fffffbfff1f0cfa6 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88801ec54188 R15: 0000000000000000
FS: 0000555556d1f380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005fdeb8 CR3: 000000001fd14000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
userfaultfd_move fs/userfaultfd.c:2008 [inline]
userfaultfd_ioctl+0x5c10/0x72c0 fs/userfaultfd.c:2126
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:857
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fe1b68902e9
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe594e4008 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffe594e41d8 RCX: 00007fe1b68902e9
RDX: 0000000020000000 RSI: 00000000c028aa05 RDI: 0000000000000003
RBP: 00007fe1b6903610 R08: 00007ffe594e41d8 R09: 00007ffe594e41d8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe594e41c8 R14: 0000000000000001 R15: 0000000000000001
</TASK>


---
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