syzbot

==================================================================
BUG: KCSAN: data-race in d_lru_shrink_move / lookup_fast

write to 0xffff88812a3f0480 of 4 bytes by task 8746 on cpu 0:
 d_lru_shrink_move+0x57/0xb0 fs/dcache.c:453
 dentry_lru_isolate_shrink+0x57/0x80 fs/dcache.c:1221
 __list_lru_walk_one+0x10b/0x390 mm/list_lru.c:222
 list_lru_walk_one+0x78/0xa0 mm/list_lru.c:266
 list_lru_walk_node+0x4b/0x190 mm/list_lru.c:295
 list_lru_walk include/linux/list_lru.h:215 [inline]
 shrink_dcache_sb+0xa2/0x1c0 fs/dcache.c:1240
 reconfigure_super+0x318/0x570 fs/super.c:940
 do_remount fs/namespace.c:2553 [inline]
 do_mount+0x1120/0x1590 fs/namespace.c:3132
 __do_sys_mount fs/namespace.c:3350 [inline]
 __se_sys_mount fs/namespace.c:3327 [inline]
 __x64_sys_mount+0x12b/0x1a0 fs/namespace.c:3327
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812a3f0480 of 4 bytes by task 5279 on cpu 1:
 d_revalidate fs/namei.c:753 [inline]
 lookup_fast+0x176/0x3a0 fs/namei.c:1479
 walk_component+0x6a/0x390 fs/namei.c:1842
 lookup_last fs/namei.c:2295 [inline]
 path_lookupat.isra.0+0x119/0x350 fs/namei.c:2319
 filename_lookup+0x145/0x2c0 fs/namei.c:2352
 user_path_at_empty+0x47/0x60 fs/namei.c:2632
 user_path_at include/linux/namei.h:59 [inline]
 vfs_statx+0xdb/0x190 fs/stat.c:197
 vfs_stat include/linux/fs.h:3279 [inline]
 __do_sys_newstat+0x50/0xb0 fs/stat.c:351
 __se_sys_newstat fs/stat.c:347 [inline]
 __x64_sys_newstat+0x37/0x50 fs/stat.c:347
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5279 Comm: systemd-udevd Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================