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

write to 0xffffc900017c7918 of 1 bytes by task 6255 on cpu 1:
 rwsem_try_write_lock kernel/locking/rwsem.c:676 [inline]
 rwsem_down_write_slowpath+0x3eb/0xab0 kernel/locking/rwsem.c:1189
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0xad/0xc0 kernel/locking/rwsem.c:1632
 kernfs_remove_by_name_ns+0x6b/0x110 fs/kernfs/dir.c:1792
 kernfs_remove_by_name include/linux/kernfs.h:644 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xa5/0x170 fs/sysfs/group.c:328
 sysfs_remove_groups+0x3a/0x80 fs/sysfs/group.c:352
 device_remove_groups drivers/base/core.c:2918 [inline]
 device_remove_attrs+0x15a/0x1a0 drivers/base/core.c:3054
 device_del+0x357/0x790 drivers/base/core.c:3964
 rfkill_unregister+0x81/0x220 net/rfkill/core.c:1159
 nfc_unregister_rfkill+0x80/0xc0 net/nfc/core.c:1175
 nci_unregister_device+0x27/0x170 net/nfc/nci/core.c:1322
 virtual_ncidev_close+0x2a/0x50 drivers/nfc/virtual_ncidev.c:168
 __fput+0x29e/0x630 fs/file_table.c:512
 fput_close_sync+0xad/0x190 fs/file_table.c:617
 __do_sys_close fs/open.c:1560 [inline]
 __se_sys_close fs/open.c:1545 [inline]
 __x64_sys_close+0x55/0xf0 fs/open.c:1545
 x64_sys_call+0x812/0x2550 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffc900017c7918 of 1 bytes by task 6267 on cpu 0:
 rwsem_down_write_slowpath+0x462/0xab0 kernel/locking/rwsem.c:1207
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0xad/0xc0 kernel/locking/rwsem.c:1632
 kernfs_add_one+0x5a/0x350 fs/kernfs/dir.c:825
 kernfs_create_dir_ns+0x124/0x170 fs/kernfs/dir.c:1130
 internal_create_group+0x2b4/0x9e0 fs/sysfs/group.c:176
 sysfs_create_group+0x1f/0x30 fs/sysfs/group.c:215
 loop_sysfs_init drivers/block/loop.c:741 [inline]
 loop_configure+0x7ec/0x9c0 drivers/block/loop.c:1100
 lo_ioctl+0x1e3/0x1430 drivers/block/loop.c:1558
 blkdev_ioctl+0x387/0x460 block/ioctl.c:798
 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+0x239d/0x2550 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 6267 Comm: syz.3.450 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================
loop3: detected capacity change from 0 to 1764
iso9660: Bad value for 'gid'
iso9660: Bad value for 'gid'
loop3: detected capacity change from 0 to 1024
EXT4-fs (loop3): stripe (4) is not aligned with cluster size (4096), stripe is disabled
EXT4-fs error (device loop3): ext4_map_blocks:790: inode #3: block 2: comm syz.3.450: lblock 2 mapped to illegal pblock 2 (length 1)
loop3: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
Quota error (device loop3): qtree_write_dquot: dquota write failed
EXT4-fs error (device loop3): ext4_map_blocks:790: inode #3: block 48: comm syz.3.450: lblock 0 mapped to illegal pblock 48 (length 1)
loop3: lost file I/O error report for ino 3 type 5 pos 0x0 len 0x0 error -117
Quota error (device loop3): v2_write_file_info: Can't write info structure
EXT4-fs error (device loop3): ext4_acquire_dquot:7069: comm syz.3.450: Failed to acquire dquot type 0
loop3: lost filesystem error report for type 5 error -117
EXT4-fs error (device loop3) in ext4_reserve_inode_write:6522: Corrupt filesystem
loop3: lost filesystem error report for type 5 error -117
EXT4-fs error (device loop3): ext4_evict_inode:269: inode #11: comm syz.3.450: mark_inode_dirty error
loop3: lost file I/O error report for ino 11 type 5 pos 0x0 len 0x0 error -117
EXT4-fs warning (device loop3): ext4_evict_inode:272: couldn't mark inode dirty (err -117)
EXT4-fs (loop3): 1 orphan inode deleted
EXT4-fs (loop3): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.