KCSAN: data-race in lru_add_drain_all / pagevec_lru_move_fn (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b3298500 Merge tag 'for-5.10/dm-fixes' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15bfe727500000
kernel config: https://syzkaller.appspot.com/x/.config?x=c949fed53798f819
dashboard link: https://syzkaller.appspot.com/bug?extid=acf152fdb6c3552de3dc
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+acf152...@syzkaller.appspotmail.com

FAT-fs (loop0): bogus number of reserved sectors
FAT-fs (loop0): Can't find a valid FAT filesystem
==================================================================
BUG: KCSAN: data-race in lru_add_drain_all / pagevec_lru_move_fn

write to 0xffff88813bd276f0 of 1 bytes by task 16391 on cpu 1:
pagevec_reinit include/linux/pagevec.h:63 [inline]
pagevec_lru_move_fn+0x175/0x190 mm/swap.c:232
__pagevec_lru_add mm/swap.c:1070 [inline]
lru_add_drain_cpu+0x75/0x290 mm/swap.c:630
lru_add_drain+0x30/0x70 mm/swap.c:734
exit_mmap+0x199/0x3b0 mm/mmap.c:3217
__mmput+0xa2/0x220 kernel/fork.c:1079
mmput+0x38/0x40 kernel/fork.c:1100
exit_mm+0x307/0x370 kernel/exit.c:486
do_exit+0x3c8/0x1630 kernel/exit.c:796
do_group_exit+0xc8/0x170 kernel/exit.c:906
get_signal+0xf9b/0x1510 kernel/signal.c:2758
arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88813bd276f0 of 1 bytes by task 16386 on cpu 0:
pagevec_count include/linux/pagevec.h:68 [inline]
lru_add_drain_all+0x108/0x3c0 mm/swap.c:837
invalidate_bdev+0x50/0x70 fs/block_dev.c:96
__loop_clr_fd+0x253/0x5a0 drivers/block/loop.c:1249
loop_clr_fd drivers/block/loop.c:1346 [inline]
lo_ioctl+0x9f9/0x11b0 drivers/block/loop.c:1704
__blkdev_driver_ioctl block/ioctl.c:228 [inline]
blkdev_ioctl+0x1d6/0x3f0 block/ioctl.c:623
block_ioctl+0x6d/0x80 fs/block_dev.c:1869
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
__x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16386 Comm: syz-executor.0 Not tainted 5.10.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

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