[moderation] [mm?] KCSAN: data-race in list_lru_add / list_lru_count_node (9)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 090472ed9c92 Merge tag 'usb-6.7-rc3' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10cffad8e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c1151391aefc0c3
dashboard link: https://syzkaller.appspot.com/bug?extid=f61c0c5e75402309e849
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/1a174462946c/disk-090472ed.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5b721db2846b/vmlinux-090472ed.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7267027fa885/bzImage-090472ed.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f61c0c...@syzkaller.appspotmail.com

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

read-write to 0xffff888103f79920 of 8 bytes by task 3104 on cpu 0:
list_lru_add+0x2a6/0x2d0 mm/list_lru.c:134
d_lru_add+0xa5/0xe0 fs/dcache.c:431
retain_dentry+0x157/0x190 fs/dcache.c:685
dput+0x108/0x1f0 fs/dcache.c:908
path_umount+0xdc/0x9a0 fs/namespace.c:1899
ksys_umount fs/namespace.c:1919 [inline]
__do_sys_umount fs/namespace.c:1924 [inline]
__se_sys_umount fs/namespace.c:1922 [inline]
__x64_sys_umount+0xb9/0xe0 fs/namespace.c:1922
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888103f79920 of 8 bytes by task 7682 on cpu 1:
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:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000000000 -> 0x0000000000000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7682 Comm: syz-executor.5 Not tainted 6.7.0-rc2-syzkaller-00242-g090472ed9c92 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================


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[syzbot]

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