[syzbot] [mm?] WARNING in try_to_unmap_one

syzbot
2024-03-05T04:38:23Z

Hello,

syzbot found the following issue on:

HEAD commit: 87adedeba51a Merge tag 'net-6.8-rc7' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15359306180000
kernel config: https://syzkaller.appspot.com/x/.config?x=dc48776003e506af
dashboard link: https://syzkaller.appspot.com/bug?extid=28895085dfb33190ed3c
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-87adedeb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/531f9afd8b25/vmlinux-87adedeb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/015cfa882009/bzImage-87adedeb.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+28895085dfb33190ed3c@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 109 at arch/x86/include/asm/pgtable.h:404 pte_uffd_wp arch/x86/include/asm/pgtable.h:404 [inline]
WARNING: CPU: 1 PID: 109 at arch/x86/include/asm/pgtable.h:404 try_to_unmap_one+0x1a84/0x29b0 mm/rmap.c:1891
Modules linked in:
CPU: 1 PID: 109 Comm: kswapd0 Not tainted 6.8.0-rc6-syzkaller-00120-g87adedeba51a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:pte_uffd_wp arch/x86/include/asm/pgtable.h:404 [inline]
RIP: 0010:try_to_unmap_one+0x1a84/0x29b0 mm/rmap.c:1891
Code: e9 d4 00 00 00 e8 8c 72 b4 ff 4d 89 ec 31 ff 41 83 e4 02 4c 89 e6 e8 8b 6d b4 ff 4d 85 e4 0f 84 8b 04 00 00 e8 6d 72 b4 ff 90 <0f> 0b 90 e8 64 72 b4 ff 48 83 cd 04 e9 21 f9 ff ff e8 56 72 b4 ff
RSP: 0018:ffffc90000ddf110 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffea0000021240 RCX: ffffffff81d771e5
RDX: ffff88801ac80000 RSI: ffffffff81d771f3 RDI: 0000000000000007
RBP: 07ffffffffa2e20a R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000004 R12: 0000000000000002
R13: 0000000000849c47 R14: dffffc0000000000 R15: ffff8880118c2f80
FS: 0000000000000000(0000) GS:ffff88802c300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000027f48000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
rmap_walk_anon+0x228/0x580 mm/rmap.c:2599
rmap_walk mm/rmap.c:2676 [inline]
rmap_walk mm/rmap.c:2671 [inline]
try_to_unmap+0x174/0x1c0 mm/rmap.c:1956
shrink_folio_list+0x1cc7/0x3ea0 mm/vmscan.c:1253
evict_folios+0x6e7/0x1b90 mm/vmscan.c:4521
try_to_shrink_lruvec+0x638/0xa10 mm/vmscan.c:4726
shrink_one+0x3f8/0x7b0 mm/vmscan.c:4765
shrink_many mm/vmscan.c:4828 [inline]
lru_gen_shrink_node mm/vmscan.c:4929 [inline]
shrink_node+0x21d0/0x3790 mm/vmscan.c:5888
kswapd_shrink_node mm/vmscan.c:6693 [inline]
balance_pgdat+0x9d2/0x1a90 mm/vmscan.c:6883
kswapd+0x5be/0xc00 mm/vmscan.c:7143
kthread+0x2c6/0x3b0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
</TASK>

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