[moderation] [mm?] KCSAN: data-race in mlock_folio / need_mlock_drain (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fbafc3e621c3 Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12d9c579e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=601ed47d1ac58cea
dashboard link: https://syzkaller.appspot.com/bug?extid=b533da774a062b47a6e4
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4bf9d6e749f0/disk-fbafc3e6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f710db8f545b/vmlinux-fbafc3e6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1099657ded40/bzImage-fbafc3e6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b533da...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in mlock_folio / need_mlock_drain

read-write to 0xffff888237d29f28 of 1 bytes by task 12420 on cpu 1:
folio_batch_add include/linux/pagevec.h:74 [inline]
mlock_folio+0x130/0x210 mm/mlock.c:258
mlock_vma_folio mm/internal.h:670 [inline]
folio_add_file_rmap_range+0x183/0x190 mm/rmap.c:1397
set_pte_range+0x304/0x780 mm/memory.c:4418
filemap_map_order0_folio mm/filemap.c:3501 [inline]
filemap_map_pages+0x581/0x900 mm/filemap.c:3547
do_fault_around mm/memory.c:4587 [inline]
do_read_fault mm/memory.c:4620 [inline]
do_fault mm/memory.c:4763 [inline]
do_pte_missing mm/memory.c:3731 [inline]
handle_pte_fault mm/memory.c:5039 [inline]
__handle_mm_fault mm/memory.c:5180 [inline]
handle_mm_fault+0x1239/0x2dd0 mm/memory.c:5345
faultin_page mm/gup.c:956 [inline]
__get_user_pages+0x402/0xe40 mm/gup.c:1239
populate_vma_page_range mm/gup.c:1677 [inline]
__mm_populate+0x216/0x330 mm/gup.c:1786
mm_populate include/linux/mm.h:3379 [inline]
vm_mmap_pgoff+0x1a7/0x240 mm/util.c:561
ksys_mmap_pgoff+0x2b8/0x330 mm/mmap.c:1425
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888237d29f28 of 1 bytes by task 3102 on cpu 0:
folio_batch_count include/linux/pagevec.h:53 [inline]
need_mlock_drain+0x30/0x50 mm/mlock.c:236
cpu_needs_drain mm/swap.c:801 [inline]
__lru_add_drain_all+0x240/0x420 mm/swap.c:889
lru_add_drain_all+0x10/0x20 mm/swap.c:905
invalidate_bdev+0x54/0x70 block/bdev.c:86
ext4_put_super+0x51b/0x7e0 fs/ext4/super.c:1361
generic_shutdown_super+0xdb/0x210 fs/super.c:696
kill_block_super+0x2a/0x60 fs/super.c:1667
ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7330
deactivate_locked_super+0x7a/0x1c0 fs/super.c:484
deactivate_super+0x9b/0xb0 fs/super.c:517
cleanup_mnt+0x272/0x2e0 fs/namespace.c:1256
__cleanup_mnt+0x19/0x20 fs/namespace.c:1263
task_work_run+0x135/0x1a0 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xd6/0xe0 kernel/entry/common.c:171
exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
do_syscall_64+0x50/0x110 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x02 -> 0x0f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3102 Comm: syz-executor.4 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.