KCSAN: data-race in cleanup_glue_dir / kernfs_unlink

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in cleanup_glue_dir / kernfs_unlink_sibling kernfs	6				1	133d	133d	0/29	auto-obsoleted due to no activity on 2025/11/20 05:47
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BUG: KCSAN: data-race in cleanup_glue_dir / kernfs_unlink_sibling

read-write to 0xffff8881481887b0 of 8 bytes by task 19064 on cpu 0:
 kernfs_unlink_sibling+0xbb/0x160 fs/kernfs/dir.c:426
 __kernfs_remove+0x3a4/0x4c0 fs/kernfs/dir.c:1519
 kernfs_remove+0x58/0x70 fs/kernfs/dir.c:1555
 sysfs_remove_dir+0x7d/0xa0 fs/sysfs/dir.c:101
 __kobject_del+0x97/0x190 lib/kobject.c:604
 kobject_del+0x2e/0x50 lib/kobject.c:627
 device_del+0x724/0x790 drivers/base/core.c:3898
 device_unregister+0x15/0x40 drivers/base/core.c:3919
 wakeup_source_sysfs_remove+0x25/0x30 drivers/base/power/wakeup_stats.c:210
 wakeup_source_unregister+0xdf/0x330 drivers/base/power/wakeup.c:239
 ep_free fs/eventpoll.c:821 [inline]
 ep_clear_and_put+0x2d5/0x320 fs/eventpoll.c:937
 ep_eventpoll_release+0x2c/0x40 fs/eventpoll.c:966
 __fput+0x29b/0x650 fs/file_table.c:468
 ____fput+0x1c/0x30 fs/file_table.c:496
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x466/0x1590 kernel/exit.c:971
 do_group_exit+0xfe/0x140 kernel/exit.c:1112
 get_signal+0xe4f/0xf60 kernel/signal.c:3034
 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x6a/0x6f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x1d3/0x2a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881481887b0 of 8 bytes by task 19063 on cpu 1:
 kobject_has_children drivers/base/core.c:3347 [inline]
 cleanup_glue_dir+0xe9/0x170 drivers/base/core.c:3413
 device_del+0x72f/0x790 drivers/base/core.c:3899
 device_unregister+0x15/0x40 drivers/base/core.c:3919
 wakeup_source_sysfs_remove+0x25/0x30 drivers/base/power/wakeup_stats.c:210
 wakeup_source_unregister+0xdf/0x330 drivers/base/power/wakeup.c:239
 ep_free fs/eventpoll.c:821 [inline]
 ep_clear_and_put+0x2d5/0x320 fs/eventpoll.c:937
 ep_eventpoll_release+0x2c/0x40 fs/eventpoll.c:966
 __fput+0x29b/0x650 fs/file_table.c:468
 ____fput+0x1c/0x30 fs/file_table.c:496
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 get_signal+0xe09/0xf60 kernel/signal.c:2807
 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x6a/0x6f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x1d3/0x2a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000001 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 19063 Comm: syz.4.5363 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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