Re: [syzbot] [mm?] WARNING in __folio_rmap_sanity_checks (2)

David Hildenbrand
2025-01-13T15:50:27Z

On 13.01.25 16:45, Liam R. Howlett wrote:
> * David Hildenbrand <david@redhat.com> [250113 10:40]:
>> On 11.01.25 10:54, syzbot wrote:
>>> Hello,
>>>
>>> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
>>> WARNING in __folio_rmap_sanity_checks
>>>
>>> page last free pid 7533 tgid 7532 stack trace:
>>> reset_page_owner include/linux/page_owner.h:25 [inline]
>>> free_pages_prepare mm/page_alloc.c:1127 [inline]
>>> free_unref_folios+0xe39/0x18b0 mm/page_alloc.c:2706
>>> folios_put_refs+0x76c/0x860 mm/swap.c:962
>>> folio_batch_release include/linux/pagevec.h:101 [inline]
>>> truncate_inode_pages_range+0x460/0x10e0 mm/truncate.c:330
>>> iomap_write_failed fs/iomap/buffered-io.c:668 [inline]
>>> iomap_write_iter fs/iomap/buffered-io.c:999 [inline]
>>> iomap_file_buffered_write+0xca5/0x11c0 fs/iomap/buffered-io.c:1039
>>> xfs_file_buffered_write+0x2de/0xac0 fs/xfs/xfs_file.c:792
>>> new_sync_write fs/read_write.c:586 [inline]
>>> vfs_write+0xaeb/0xd30 fs/read_write.c:679
>>> ksys_write+0x18f/0x2b0 fs/read_write.c:731
>>> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>>> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>> ------------[ cut here ]------------
>>> WARNING: CPU: 0 PID: 7538 at ./include/linux/rmap.h:216 __folio_rmap_sanity_checks+0x33f/0x590 include/linux/rmap.h:216
>>> Modules linked in:
>>> CPU: 0 UID: 0 PID: 7538 Comm: syz.1.57 Not tainted 6.13.0-rc6-syzkaller-gcd6313beaeae #0
>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
>>> RIP: 0010:__folio_rmap_sanity_checks+0x33f/0x590 include/linux/rmap.h:216
>>> Code: 0f 0b 90 e9 b7 fd ff ff e8 ee af ab ff 48 ff cb e9 f8 fd ff ff e8 e1 af ab ff 4c 89 e7 48 c7 c6 c0 9c 15 8c e8 82 6f f5 ff 90 <0f> 0b 90 e9 e9 fd ff ff e8 c4 af ab ff 48 ff cb e9 34 fe ff ff e8
>>> RSP: 0018:ffffc9000c38efd8 EFLAGS: 00010246
>>> RAX: f8a45fcd41963a00 RBX: ffffea00014f8000 RCX: ffffc9000c38eb03
>>> RDX: 0000000000000005 RSI: ffffffff8c0aa3e0 RDI: ffffffff8c5fa860
>>> RBP: 0000000000013186 R08: ffffffff901978b7 R09: 1ffffffff2032f16
>>> R10: dffffc0000000000 R11: fffffbfff2032f17 R12: ffffea00014f0000
>>> R13: ffffea00014f8080 R14: 0000000000000000 R15: 0000000000000002
>>> FS: 00007f14451f96c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 0000000020000140 CR3: 0000000073716000 CR4: 00000000003526f0
>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>>> Call Trace:
>>> <TASK>
>>> __folio_add_rmap mm/rmap.c:1170 [inline]
>>> __folio_add_file_rmap mm/rmap.c:1489 [inline]
>>> folio_add_file_rmap_ptes+0x82/0x380 mm/rmap.c:1511
>>> set_pte_range+0x30c/0x750 mm/memory.c:5065
>>> filemap_map_folio_range mm/filemap.c:3563 [inline]
>>> filemap_map_pages+0xfbe/0x1900 mm/filemap.c:3672
>>> do_fault_around mm/memory.c:5280 [inline]
>>> do_read_fault mm/memory.c:5313 [inline]
>>> do_fault mm/memory.c:5456 [inline]
>>> do_pte_missing mm/memory.c:3979 [inline]
>>> handle_pte_fault+0x3888/0x5ed0 mm/memory.c:5801
>>> __handle_mm_fault mm/memory.c:5944 [inline]
>>> handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6112
>>> faultin_page mm/gup.c:1196 [inline]
>>> __get_user_pages+0x1c82/0x49e0 mm/gup.c:1494
>>> populate_vma_page_range+0x264/0x330 mm/gup.c:1932
>>> __mm_populate+0x27a/0x460 mm/gup.c:2035
>>> mm_populate include/linux/mm.h:3397 [inline]
>>> vm_mmap_pgoff+0x2c3/0x3d0 mm/util.c:580
>>> ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:546
>>> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>>> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>> RIP: 0033:0x7f1445385d29
>>> 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:00007f14451f9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
>>> RAX: ffffffffffffffda RBX: 00007f1445575fa0 RCX: 00007f1445385d29
>>> RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000000020000000
>>> RBP: 00007f1445401b08 R08: 0000000000000004 R09: 0000000000000000
>>> R10: 0000000000028011 R11: 0000000000000246 R12: 0000000000000000
>>> R13: 0000000000000000 R14: 00007f1445575fa0 R15: 00007ffe4c3a7978
>>> </TASK>
>>>
>>>
>>> Tested on:
>>>
>>> commit: cd6313be Revert "vmstat: disable vmstat_work on vmstat..
>>> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm mm-stable
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=10b34bc4580000
>>> kernel config: https://syzkaller.appspot.com/x/.config?x=d18955ff6936aa88
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=c0673e1f1f054fac28c2
>>> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>>
>> I tried reproducing it in manually in an x86-64 VM with the provided
>> config and C reproducer, so far no luck :(
>
> Yeah, same here.
>
> Thanks for testing mm-stable with the bot.

I have a suspicion of what might go very wrong here ... let me try
playing with a manual reproducer to trigger the scenario I have in mind.

So far, I don't think this issue is related to the latest VMA changes.

We saw it upstream so far once, and I suspect it's an upstream issue.

--
Cheers,

David / dhildenb