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BUG: KCSAN: data-race in __kernfs_remove / cleanup_glue_dir

write to 0xffff888101c17bc0 of 8 bytes by task 13333 on cpu 1:
 kernfs_unlink_sibling fs/kernfs/dir.c:397 [inline]
 __kernfs_remove+0x592/0x6d0 fs/kernfs/dir.c:1359
 kernfs_remove+0x1d/0x30 fs/kernfs/dir.c:1385
 sysfs_remove_dir+0x92/0xb0 fs/sysfs/dir.c:102
 __kobject_del lib/kobject.c:620 [inline]
 kobject_del+0xb7/0x110 lib/kobject.c:643
 device_del+0x845/0x8c0 drivers/base/core.c:3595
 device_unregister+0x11/0x30 drivers/base/core.c:3616
 bdi_unregister+0x202/0x270 mm/backing-dev.c:952
 del_gendisk+0x221/0x3e0 block/genhd.c:609
 loop_remove drivers/block/loop.c:2419 [inline]
 loop_control_remove drivers/block/loop.c:2476 [inline]
 loop_control_ioctl+0x3c1/0x430 drivers/block/loop.c:2514
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888101c17bc0 of 8 bytes by task 13337 on cpu 0:
 kobject_has_children include/linux/kobject.h:135 [inline]
 cleanup_glue_dir+0xce/0x140 drivers/base/core.c:3097
 device_del+0x850/0x8c0 drivers/base/core.c:3596
 device_unregister+0x11/0x30 drivers/base/core.c:3616
 bdi_unregister+0x202/0x270 mm/backing-dev.c:952
 del_gendisk+0x221/0x3e0 block/genhd.c:609
 loop_remove drivers/block/loop.c:2419 [inline]
 loop_control_remove drivers/block/loop.c:2476 [inline]
 loop_control_ioctl+0x3c1/0x430 drivers/block/loop.c:2514
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000002 -> 0x0000000000000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13337 Comm: syz-executor.4 Not tainted 5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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