syzbot

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BUG: KCSAN: data-race in __fsnotify_parent / d_lru_shrink_move

write to 0xffff8881250f93c0 of 4 bytes by task 14462 on cpu 1:
 d_lru_shrink_move+0x5c/0xc0 fs/dcache.c:453
 dentry_lru_isolate_shrink+0x5e/0x90 fs/dcache.c:1219
 __list_lru_walk_one+0x110/0x390 mm/list_lru.c:232
 list_lru_walk_one+0x84/0xb0 mm/list_lru.c:276
 list_lru_walk_node+0x4c/0x190 mm/list_lru.c:305
 list_lru_walk include/linux/list_lru.h:215 [inline]
 shrink_dcache_sb+0xa1/0x1d0 fs/dcache.c:1238
 reconfigure_super+0x31a/0x570 fs/super.c:938
 do_remount fs/namespace.c:2553 [inline]
 do_mount+0x1136/0x14f0 fs/namespace.c:3133
 ksys_mount+0xe8/0x160 fs/namespace.c:3351
 __do_sys_mount fs/namespace.c:3365 [inline]
 __se_sys_mount fs/namespace.c:3362 [inline]
 __x64_sys_mount+0x70/0x90 fs/namespace.c:3362
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881250f93c0 of 4 bytes by task 14464 on cpu 0:
 __fsnotify_parent+0x55/0x230 fs/notify/fsnotify.c:151
 fsnotify_parent include/linux/fsnotify.h:40 [inline]
 fsnotify_path include/linux/fsnotify.h:50 [inline]
 fsnotify_perm include/linux/fsnotify.h:85 [inline]
 security_file_permission+0x194/0x280 security/security.c:1379
 rw_verify_area+0xe1/0x250 fs/read_write.c:399
 vfs_read+0xf0/0x2c0 fs/read_write.c:457
 kernel_read+0x79/0xb0 fs/read_write.c:440
 load_elf_binary+0x460/0x2ec0 fs/binfmt_elf.c:744
 search_binary_handler fs/exec.c:1659 [inline]
 search_binary_handler+0x127/0x420 fs/exec.c:1636
 exec_binprm fs/exec.c:1702 [inline]
 __do_execve_file.isra.0+0xb76/0x11d0 fs/exec.c:1822
 do_execveat_common fs/exec.c:1868 [inline]
 do_execve fs/exec.c:1885 [inline]
 __do_sys_execve fs/exec.c:1961 [inline]
 __se_sys_execve fs/exec.c:1956 [inline]
 __x64_sys_execve+0x62/0x80 fs/exec.c:1956
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14464 Comm: udevd Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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