==================================================================
BUG: KCSAN: data-race in rwsem_down_write_slowpath / rwsem_down_write_slowpath

write to 0xffffc90001807870 of 1 bytes by task 10507 on cpu 1:
 rwsem_try_write_lock kernel/locking/rwsem.c:653 [inline]
 rwsem_down_write_slowpath+0x3c9/0xa90 kernel/locking/rwsem.c:1159
 __down_write_common kernel/locking/rwsem.c:1317 [inline]
 __down_write kernel/locking/rwsem.c:1326 [inline]
 down_write+0xab/0xc0 kernel/locking/rwsem.c:1591
 kernfs_add_one+0x5a/0x280 fs/kernfs/dir.c:796
 kernfs_create_dir_ns+0x90/0xe0 fs/kernfs/dir.c:1098
 sysfs_create_dir_ns+0xd4/0x1d0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x47a/0x780 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0xdb/0x150 lib/kobject.c:426
 device_add+0x2f6/0x770 drivers/base/core.c:3629
 wakeup_source_device_create drivers/base/power/wakeup_stats.c:163 [inline]
 wakeup_source_sysfs_add+0x15a/0x1d0 drivers/base/power/wakeup_stats.c:183
 wakeup_source_register+0xfd/0x240 drivers/base/power/wakeup.c:218
 ep_create_wakeup_source fs/eventpoll.c:1501 [inline]
 ep_insert+0x8ca/0xe00 fs/eventpoll.c:1630
 do_epoll_ctl+0x686/0x8a0 fs/eventpoll.c:2341
 __do_sys_epoll_ctl fs/eventpoll.c:2392 [inline]
 __se_sys_epoll_ctl fs/eventpoll.c:2383 [inline]
 __x64_sys_epoll_ctl+0xcb/0x100 fs/eventpoll.c:2383
 x64_sys_call+0x2a8b/0x3020 arch/x86/include/generated/asm/syscalls_64.h:234
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffc90001807870 of 1 bytes by task 10535 on cpu 0:
 rwsem_down_write_slowpath+0x43d/0xa90 kernel/locking/rwsem.c:1177
 __down_write_common kernel/locking/rwsem.c:1317 [inline]
 __down_write kernel/locking/rwsem.c:1326 [inline]
 down_write+0xab/0xc0 kernel/locking/rwsem.c:1591
 kernfs_activate+0x50/0x220 fs/kernfs/dir.c:1430
 kernfs_add_one+0x212/0x280 fs/kernfs/dir.c:839
 __kernfs_create_file+0x145/0x180 fs/kernfs/file.c:1086
 sysfs_add_file_mode_ns+0x132/0x1b0 fs/sysfs/file.c:313
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x441/0x9e0 fs/sysfs/group.c:189
 sysfs_create_group+0x1f/0x30 fs/sysfs/group.c:215
 loop_sysfs_init drivers/block/loop.c:731 [inline]
 loop_configure+0x7ee/0x9c0 drivers/block/loop.c:1076
 lo_ioctl+0x1e1/0x13a0 drivers/block/loop.c:1534
 blkdev_ioctl+0x387/0x460 block/ioctl.c:804
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1563/0x3020 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10535 Comm: syz.3.1799 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================
loop3: detected capacity change from 0 to 128
EXT4-fs (loop3): mounted filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09 r/w without journal. Quota mode: none.
ext4 filesystem being mounted at /365/file0 supports timestamps until 2038-01-19 (0x7fffffff)