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BUG: KCSAN: data-race in rwsem_down_write_slowpath / rwsem_down_write_slowpath

write to 0xffffc90002a73b68 of 1 bytes by task 23339 on cpu 1:
 rwsem_try_write_lock kernel/locking/rwsem.c:676 [inline]
 rwsem_down_write_slowpath+0x3dd/0xac0 kernel/locking/rwsem.c:1189
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0xab/0xc0 kernel/locking/rwsem.c:1626
 kernfs_add_one+0x5a/0x280 fs/kernfs/dir.c:826
 __kernfs_create_file+0x145/0x180 fs/kernfs/file.c:1086
 sysfs_add_file_mode_ns+0x132/0x1b0 fs/sysfs/file.c:313
 sysfs_create_file_ns+0xd9/0x120 fs/sysfs/file.c:374
 sysfs_create_file include/linux/sysfs.h:774 [inline]
 device_create_file+0xa5/0x110 drivers/base/core.c:3056
 device_add+0x32e/0x790 drivers/base/core.c:3638
 netdev_register_kobject+0x109/0x230 net/core/net-sysfs.c:2343
 register_netdevice+0xaaf/0x1160 net/core/dev.c:11423
 bond_newlink+0x2f/0xb0 drivers/net/bonding/bond_netlink.c:614
 rtnl_newlink_create+0x1e4/0x650 net/core/rtnetlink.c:3864
 __rtnl_newlink net/core/rtnetlink.c:3995 [inline]
 rtnl_newlink+0x1185/0x1400 net/core/rtnetlink.c:4110
 rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:6997
 netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2555
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:7024
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5a8/0x680 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x563/0x5b0 net/socket.c:2698
 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2752
 __sys_sendmsg net/socket.c:2784 [inline]
 __do_sys_sendmsg net/socket.c:2789 [inline]
 __se_sys_sendmsg net/socket.c:2787 [inline]
 __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2787
 x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffc90002a73b68 of 1 bytes by task 21124 on cpu 0:
 rwsem_down_write_slowpath+0x44f/0xac0 kernel/locking/rwsem.c:1207
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0xab/0xc0 kernel/locking/rwsem.c:1626
 kernfs_remove_by_name_ns+0x6b/0x110 fs/kernfs/dir.c:1793
 kernfs_remove_by_name include/linux/kernfs.h:639 [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
 __kobject_del+0x4b/0x190 lib/kobject.c:595
 kobject_del+0x2e/0x50 lib/kobject.c:627
 ext4_unregister_sysfs+0x84/0xa0 fs/ext4/sysfs.c:654
 ext4_put_super+0x4c/0x7b0 fs/ext4/super.c:1299
 generic_shutdown_super+0xee/0x220 fs/super.c:646
 kill_block_super+0x2a/0x70 fs/super.c:1725
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7492
 deactivate_locked_super+0x75/0x1c0 fs/super.c:476
 deactivate_super+0x97/0xa0 fs/super.c:509
 cleanup_mnt+0x2bb/0x330 fs/namespace.c:1312
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1319
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x211/0x820 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x232/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 21124 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.