KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fd0aa1a4 Merge tag 'for-linus' of git://git.kernel.org/pub..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11db7c34300000
kernel config: https://syzkaller.appspot.com/x/.config?x=8b2d74341df68ad2
dashboard link: https://syzkaller.appspot.com/bug?extid=8302fb2b854bb5b51ac1
compiler: Debian clang version 11.0.1-2
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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+8302fb...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu

write to 0xffff888237c26da0 of 8 bytes by task 15254 on cpu 0:
__invalidate_bh_lrus fs/buffer.c:1418 [inline]
invalidate_bh_lrus_cpu+0xad/0xe0 fs/buffer.c:1459
lru_add_drain_cpu+0x243/0x270 mm/swap.c:645
lru_add_drain mm/swap.c:724 [inline]
__pagevec_release+0x57/0xa0 mm/swap.c:989
pagevec_release include/linux/pagevec.h:81 [inline]
__invalidate_mapping_pages+0x27f/0x310 mm/truncate.c:507
invalidate_mapping_pages+0x23/0x30 mm/truncate.c:532
invalidate_bdev+0x61/0x70 fs/block_dev.c:97
__loop_clr_fd+0x2e2/0x640 drivers/block/loop.c:1242
loop_clr_fd drivers/block/loop.c:1337 [inline]
lo_ioctl+0x9eb/0x11f0 drivers/block/loop.c:1695
blkdev_ioctl+0x1d0/0x3c0 block/ioctl.c:585
block_ioctl+0x6d/0x80 fs/block_dev.c:1662
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:1069 [inline]
__se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055
__x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237c26da0 of 8 bytes by task 15252 on cpu 1:
has_bh_in_lru+0x31/0x1c0 fs/buffer.c:1440
__lru_add_drain_all+0x25b/0x3e0 mm/swap.c:834
lru_add_drain_all+0xc/0x10 mm/swap.c:850
invalidate_bdev+0x50/0x70 fs/block_dev.c:96
__loop_clr_fd+0x2e2/0x640 drivers/block/loop.c:1242
loop_clr_fd drivers/block/loop.c:1337 [inline]
lo_ioctl+0x9eb/0x11f0 drivers/block/loop.c:1695
blkdev_ioctl+0x1d0/0x3c0 block/ioctl.c:585
block_ioctl+0x6d/0x80 fs/block_dev.c:1662
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:1069 [inline]
__se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055
__x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff888102bfbdd0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15252 Comm: syz-executor.3 Not tainted 5.13.0-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.