[moderation] [mm?] KCSAN: data-race in __lru_add_drain_all / deactivate_file_folio (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 33d8d8ec31b5 Merge tag 'input-for-v7.1-rc6' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12faa0ae580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f571f22917457cd8
dashboard link: https://syzkaller.appspot.com/bug?extid=598f5451891048e9ece4
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
CC: [ak...@linux-foundation.org axelra...@google.com bao...@kernel.org b...@redhat.com chr...@kernel.org kas...@tencent.com linux-...@vger.kernel.org linu...@kvack.org nph...@gmail.com qi.z...@linux.dev shakee...@linux.dev shik...@huaweicloud.com wei...@google.com youngj...@lge.com yua...@google.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2fb5da198087/disk-33d8d8ec.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c67f2d5cd0ce/vmlinux-33d8d8ec.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ade470e04c46/bzImage-33d8d8ec.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+598f54...@syzkaller.appspotmail.com

EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in __lru_add_drain_all / deactivate_file_folio

read-write to 0xffff888237c267e8 of 1 bytes by task 3307 on cpu 0:
folio_batch_add include/linux/folio_batch.h:77 [inline]
__folio_batch_add_and_move mm/swap.c:194 [inline]
deactivate_file_folio+0xb6/0x1b0 mm/swap.c:701
mapping_try_invalidate+0x2c9/0x430 mm/truncate.c:567
invalidate_mapping_pages+0x27/0x40 mm/truncate.c:602
invalidate_bdev+0x58/0x70 block/bdev.c:102
ext4_put_super+0x610/0x7b0 fs/ext4/super.c:1355
generic_shutdown_super+0xee/0x220 fs/super.c:646
kill_block_super+0x2a/0x70 fs/super.c:1725
ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7492
deactivate_locked_super+0x75/0x1c0 fs/super.c:476
deactivate_super+0x97/0xa0 fs/super.c:509
cleanup_mnt+0x2bb/0x330 fs/namespace.c:1312
__cleanup_mnt+0x19/0x20 fs/namespace.c:1319
task_work_run+0x130/0x1a0 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x211/0x820 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x232/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c267e8 of 1 bytes by task 3306 on cpu 1:
folio_batch_count include/linux/folio_batch.h:56 [inline]
cpu_needs_drain mm/swap.c:788 [inline]
__lru_add_drain_all+0x1d5/0x450 mm/swap.c:883
lru_add_drain_all+0x10/0x20 mm/swap.c:899
invalidate_bdev+0x47/0x70 block/bdev.c:101
ext4_put_super+0x610/0x7b0 fs/ext4/super.c:1355
generic_shutdown_super+0xee/0x220 fs/super.c:646
kill_block_super+0x2a/0x70 fs/super.c:1725
ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7492
deactivate_locked_super+0x75/0x1c0 fs/super.c:476
deactivate_super+0x97/0xa0 fs/super.c:509
cleanup_mnt+0x2bb/0x330 fs/namespace.c:1312
__cleanup_mnt+0x19/0x20 fs/namespace.c:1319
task_work_run+0x130/0x1a0 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x211/0x820 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x232/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3306 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
==================================================================


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