[moderation] [kernfs?] KCSAN: data-race in kernfs_iop_permission / kernfs_iop_permission

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5bd7ef53ffe5 Merge tag 'pull-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=138ac6e1e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=d6f4b50a94fc12a6
dashboard link: https://syzkaller.appspot.com/bug?extid=eed9764a046ca883917c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [gre...@linuxfoundation.org linux-...@vger.kernel.org linux-...@vger.kernel.org t...@kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7f3391cfbb23/disk-5bd7ef53.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b6dcdd26f70f/vmlinux-5bd7ef53.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6b7927d1c4c2/bzImage-5bd7ef53.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+eed976...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in kernfs_iop_permission / kernfs_iop_permission

write to 0xffff888104f9a7c0 of 8 bytes by task 18309 on cpu 1:
inode_set_mtime_to_ts include/linux/fs.h:1567 [inline]
set_inode_attr fs/kernfs/inode.c:163 [inline]
kernfs_refresh_inode fs/kernfs/inode.c:177 [inline]
kernfs_iop_permission+0x14c/0x220 fs/kernfs/inode.c:288
do_inode_permission fs/namei.c:462 [inline]
inode_permission+0x184/0x300 fs/namei.c:529
may_lookup fs/namei.c:1724 [inline]
link_path_walk+0x19e/0x7e0 fs/namei.c:2271
path_openat+0x1a0/0x1d70 fs/namei.c:3775
do_filp_open+0xf6/0x200 fs/namei.c:3809
do_sys_openat2+0xab/0x110 fs/open.c:1440
do_sys_open fs/open.c:1455 [inline]
__do_sys_open fs/open.c:1463 [inline]
__se_sys_open fs/open.c:1459 [inline]
__x64_sys_open+0xe6/0x110 fs/open.c:1459
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

write to 0xffff888104f9a7c0 of 8 bytes by task 18312 on cpu 0:
inode_set_mtime_to_ts include/linux/fs.h:1567 [inline]
set_inode_attr fs/kernfs/inode.c:163 [inline]
kernfs_refresh_inode fs/kernfs/inode.c:177 [inline]
kernfs_iop_permission+0x14c/0x220 fs/kernfs/inode.c:288
do_inode_permission fs/namei.c:462 [inline]
inode_permission+0x184/0x300 fs/namei.c:529
may_lookup fs/namei.c:1724 [inline]
link_path_walk+0x19e/0x7e0 fs/namei.c:2271
path_openat+0x1a0/0x1d70 fs/namei.c:3775
do_filp_open+0xf6/0x200 fs/namei.c:3809
do_sys_openat2+0xab/0x110 fs/open.c:1440
do_sys_open fs/open.c:1455 [inline]
__do_sys_open fs/open.c:1463 [inline]
__se_sys_open fs/open.c:1459 [inline]
__x64_sys_open+0xe6/0x110 fs/open.c:1459
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: 0x000000002b27f529 -> 0x0000000031b64f77

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18312 Comm: syz-executor.3 Not tainted 6.7.0-rc5-syzkaller-00047-g5bd7ef53ffe5 #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.