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BUG: KCSAN: data-race in generic_permission / kernfs_refresh_inode

write to 0xffff8881231b56d8 of 2 bytes by task 8184 on cpu 1:
 kernfs_refresh_inode+0x44/0x180 fs/kernfs/inode.c:173
 kernfs_iop_permission+0x66/0xa0 fs/kernfs/inode.c:284
 do_inode_permission fs/namei.c:384 [inline]
 inode_permission+0x241/0x3c0 fs/namei.c:449
 may_lookup fs/namei.c:1700 [inline]
 link_path_walk.part.0+0x622/0xa90 fs/namei.c:2082
 link_path_walk fs/namei.c:2070 [inline]
 path_openat+0x14f/0x3530 fs/namei.c:3532
 do_filp_open+0x11e/0x1b0 fs/namei.c:3563
 do_sys_open+0x3b3/0x4f0 fs/open.c:1089
 __do_sys_open fs/open.c:1107 [inline]
 __se_sys_open fs/open.c:1102 [inline]
 __x64_sys_open+0x55/0x70 fs/open.c:1102
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881231b56d8 of 2 bytes by task 7743 on cpu 0:
 acl_permission_check fs/namei.c:295 [inline]
 generic_permission+0x36/0x3d0 fs/namei.c:339
 kernfs_iop_permission+0x7d/0xa0 fs/kernfs/inode.c:287
 do_inode_permission fs/namei.c:384 [inline]
 inode_permission+0x241/0x3c0 fs/namei.c:449
 may_lookup fs/namei.c:1700 [inline]
 link_path_walk.part.0+0x622/0xa90 fs/namei.c:2082
 link_path_walk fs/namei.c:2267 [inline]
 path_lookupat.isra.0+0x77/0x5a0 fs/namei.c:2315
 filename_lookup+0x145/0x2d0 fs/namei.c:2346
 user_path_at_empty+0x4c/0x70 fs/namei.c:2606
 do_readlinkat+0x84/0x220 fs/stat.c:399
 __do_sys_readlink fs/stat.c:432 [inline]
 __se_sys_readlink fs/stat.c:429 [inline]
 __x64_sys_readlink+0x51/0x70 fs/stat.c:429
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7743 Comm: udevd Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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