[moderation] [mm?] KCSAN: data-race in list_lru_count_node / list_lru_del

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 26aff849438c Merge tag 'bcachefs-2023-12-10' of https://ev..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1536047ce80000
kernel config: https://syzkaller.appspot.com/x/.config?x=d6f4b50a94fc12a6
dashboard link: https://syzkaller.appspot.com/bug?extid=fd43ad338ceb048feb58
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/8cb0a65efd0d/disk-26aff849.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b763919fdd61/vmlinux-26aff849.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cc7af8b2772b/bzImage-26aff849.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fd43ad...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in list_lru_count_node / list_lru_del

read-write to 0xffff88810282bda0 of 8 bytes by task 3097 on cpu 1:
list_lru_del+0x25c/0x290 mm/list_lru.c:154
d_lru_del fs/dcache.c:441 [inline]
select_collect+0x117/0x2a0 fs/dcache.c:1565
d_walk+0x291/0x460 fs/dcache.c:1386
shrink_dcache_parent+0x85/0x1a0 fs/dcache.c:1625
vfs_rmdir+0x283/0x2f0 fs/namei.c:4193
do_rmdir+0x194/0x320 fs/namei.c:4248
__do_sys_unlinkat fs/namei.c:4424 [inline]
__se_sys_unlinkat fs/namei.c:4418 [inline]
__x64_sys_unlinkat+0xa4/0xb0 fs/namei.c:4418
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 0xffff88810282bda0 of 8 bytes by task 26224 on cpu 0:
list_lru_count_node+0x2c/0x40 mm/list_lru.c:201
list_lru_count include/linux/list_lru.h:131 [inline]
shrink_dcache_sb+0x1bc/0x290 fs/dcache.c:1322
reconfigure_super+0x3ef/0x580 fs/super.c:1121
do_remount fs/namespace.c:2884 [inline]
path_mount+0x969/0xb30 fs/namespace.c:3656
do_mount fs/namespace.c:3677 [inline]
__do_sys_mount fs/namespace.c:3886 [inline]
__se_sys_mount+0x27f/0x2d0 fs/namespace.c:3863
__x64_sys_mount+0x67/0x80 fs/namespace.c:3863
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

value changed: 0x0000000000004ab6 -> 0x0000000000004ab1

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26224 Comm: syz-executor.5 Not tainted 6.7.0-rc5-syzkaller-00014-g26aff849438c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================
EXT4-fs (sda1): re-mounted 5941fea2-f5fa-4b4e-b5ef-9af118b27b95 r/w. Quota mode: none.


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[syzbot]

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