[moderation] [mm?] KCSAN: data-race in munlock_folio / need_mlock_drain (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c942a0cd3603 Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=132dc208980000
kernel config: https://syzkaller.appspot.com/x/.config?x=4128b708dfac799b
dashboard link: https://syzkaller.appspot.com/bug?extid=8b556a2f194286719db7
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/0ccaed2938dd/disk-c942a0cd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f45fb1a92144/vmlinux-c942a0cd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9ff8e1609ba0/bzImage-c942a0cd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8b556a...@syzkaller.appspotmail.com

EXT4-fs (loop4): unmounting filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09.
==================================================================
BUG: KCSAN: data-race in munlock_folio / need_mlock_drain

read-write to 0xffff888237d2b410 of 1 bytes by task 22368 on cpu 1:
folio_batch_add include/linux/pagevec.h:77 [inline]
munlock_folio+0x42/0x130 mm/mlock.c:301
munlock_vma_folio mm/internal.h:782 [inline]
__folio_remove_rmap mm/rmap.c:1573 [inline]
folio_remove_rmap_ptes+0x179/0x180 mm/rmap.c:1590
zap_present_folio_ptes mm/memory.c:1503 [inline]
zap_present_ptes mm/memory.c:1563 [inline]
zap_pte_range mm/memory.c:1605 [inline]
zap_pmd_range mm/memory.c:1722 [inline]
zap_pud_range mm/memory.c:1751 [inline]
zap_p4d_range mm/memory.c:1772 [inline]
unmap_page_range+0xe36/0x22d0 mm/memory.c:1793
unmap_single_vma+0x142/0x1d0 mm/memory.c:1839
unmap_vmas+0x18d/0x2b0 mm/memory.c:1883
exit_mmap+0x1a2/0x6f0 mm/mmap.c:3267
__mmput+0x28/0x1c0 kernel/fork.c:1346
mmput+0x4c/0x60 kernel/fork.c:1368
exit_mm+0xe4/0x190 kernel/exit.c:569
do_exit+0x57e/0x1740 kernel/exit.c:865
do_group_exit+0x102/0x150 kernel/exit.c:1027
get_signal+0xf2f/0x1080 kernel/signal.c:2911
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d2b410 of 1 bytes by task 21506 on cpu 0:
folio_batch_count include/linux/pagevec.h:56 [inline]
need_mlock_drain+0x30/0x50 mm/mlock.c:235
cpu_needs_drain mm/swap.c:816 [inline]
__lru_add_drain_all+0x240/0x420 mm/swap.c:904
lru_add_drain_all+0x10/0x20 mm/swap.c:920
invalidate_bdev+0x54/0x80 block/bdev.c:95
ext4_put_super+0x51b/0x7e0 fs/ext4/super.c:1361
generic_shutdown_super+0xde/0x210 fs/super.c:641
kill_block_super+0x2a/0x70 fs/super.c:1675
ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7327
deactivate_locked_super+0x7d/0x1c0 fs/super.c:472
deactivate_super+0x9f/0xb0 fs/super.c:505
cleanup_mnt+0x272/0x2e0 fs/namespace.c:1267
__cleanup_mnt+0x19/0x20 fs/namespace.c:1274
task_work_run+0x13a/0x1a0 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x14 -> 0x1f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21506 Comm: syz-executor.4 Tainted: G W 6.9.0-rc5-syzkaller-00159-gc942a0cd3603 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================
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 76b65be2-f6da-4727-8c75-0525a5b65a09.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000d40000.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000d40000.
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.


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