syzbot

==================================================================
BUG: KCSAN: data-race in generic_permission / kernfs_refresh_inode

read to 0xffff888128f24788 of 2 bytes by task 6451 on cpu 1:
 acl_permission_check fs/namei.c:295 [inline]
 generic_permission+0x36/0x410 fs/namei.c:339
 kernfs_iop_permission+0x7d/0xa0 fs/kernfs/inode.c:286
 do_inode_permission fs/namei.c:384 [inline]
 inode_permission+0x241/0x370 fs/namei.c:449
 may_lookup fs/namei.c:1696 [inline]
 link_path_walk.part.0+0x622/0xa90 fs/namei.c:2071
 link_path_walk fs/namei.c:2059 [inline]
 path_openat+0x14f/0x3580 fs/namei.c:3536
 do_filp_open+0x11e/0x1b0 fs/namei.c:3567
 do_sys_open+0x3b3/0x4f0 fs/open.c:1097
 __do_sys_open fs/open.c:1115 [inline]
 __se_sys_open fs/open.c:1110 [inline]
 __x64_sys_open+0x55/0x70 fs/open.c:1110
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff888128f24788 of 2 bytes by task 5567 on cpu 0:
 kernfs_refresh_inode+0x42/0x140 fs/kernfs/inode.c:172
 kernfs_iop_permission+0x66/0xa0 fs/kernfs/inode.c:283
 do_inode_permission fs/namei.c:384 [inline]
 inode_permission+0x241/0x370 fs/namei.c:449
 may_lookup fs/namei.c:1696 [inline]
 link_path_walk.part.0+0x622/0xa90 fs/namei.c:2071
 link_path_walk fs/namei.c:2059 [inline]
 path_openat+0x14f/0x3580 fs/namei.c:3536
 do_filp_open+0x11e/0x1b0 fs/namei.c:3567
 do_sys_open+0x3b3/0x4f0 fs/open.c:1097
 __do_sys_open fs/open.c:1115 [inline]
 __se_sys_open fs/open.c:1110 [inline]
 __x64_sys_open+0x55/0x70 fs/open.c:1110
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5567 Comm: udevd Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================