KCSAN: data-race in tomoyo_supervisor / tomoyo_supervisor (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 111e91a6 Merge tag 's390-5.10-4' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=147f8af6500000
kernel config: https://syzkaller.appspot.com/x/.config?x=e0bbcd06922dbd46
dashboard link: https://syzkaller.appspot.com/bug?extid=81fbc13e36568934ffa4
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [jmo...@namei.org linux-...@vger.kernel.org linux-secu...@vger.kernel.org penguin...@I-love.SAKURA.ne.jp se...@hallyn.com take...@nttdata.co.jp]

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+81fbc1...@syzkaller.appspotmail.com

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

write to 0xffffffff883bac78 of 8 bytes by task 4892 on cpu 1:
tomoyo_update_stat security/tomoyo/common.c:2340 [inline]
tomoyo_supervisor+0x176/0xb20 security/tomoyo/common.c:2079
tomoyo_audit_path_log security/tomoyo/file.c:168 [inline]
tomoyo_path_permission security/tomoyo/file.c:587 [inline]
tomoyo_path_perm+0x261/0x330 security/tomoyo/file.c:838
tomoyo_inode_getattr+0x18/0x20 security/tomoyo/tomoyo.c:123
security_inode_getattr+0x7f/0xd0 security/security.c:1279
vfs_getattr fs/stat.c:121 [inline]
vfs_statx+0xf8/0x270 fs/stat.c:189
vfs_fstatat fs/stat.c:207 [inline]
vfs_lstat include/linux/fs.h:3125 [inline]
__do_sys_newlstat fs/stat.c:362 [inline]
__se_sys_newlstat+0x46/0x250 fs/stat.c:356
__x64_sys_newlstat+0x2d/0x40 fs/stat.c:356
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffffffff883bac78 of 8 bytes by task 15487 on cpu 0:
tomoyo_update_stat security/tomoyo/common.c:2340 [inline]
tomoyo_supervisor+0x176/0xb20 security/tomoyo/common.c:2079
tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline]
tomoyo_path_number_perm+0x227/0x2d0 security/tomoyo/file.c:734
tomoyo_path_mknod+0xe0/0x100 security/tomoyo/tomoyo.c:240
security_path_mknod+0x98/0xf0 security/security.c:1078
may_o_create fs/namei.c:2928 [inline]
lookup_open fs/namei.c:3069 [inline]
open_last_lookups fs/namei.c:3178 [inline]
path_openat+0x835/0x20a0 fs/namei.c:3366
do_filp_open+0xbd/0x1d0 fs/namei.c:3396
do_sys_openat2+0xa3/0x240 fs/open.c:1168
do_sys_open fs/open.c:1184 [inline]
__do_sys_openat fs/open.c:1200 [inline]
__se_sys_openat fs/open.c:1195 [inline]
__x64_sys_openat+0xef/0x110 fs/open.c:1195
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: 15487 Comm: syz-executor.0 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

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