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BUG: KCSAN: data-race in rwsem_down_write_slowpath / rwsem_down_write_slowpath

write to 0xffffc900000cf6f0 of 1 bytes by task 21322 on cpu 0:
 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
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x441/0x9f0 fs/sysfs/group.c:189
 internal_create_groups fs/sysfs/group.c:229 [inline]
 sysfs_create_groups+0x3f/0xf0 fs/sysfs/group.c:255
 device_add_groups drivers/base/core.c:2837 [inline]
 device_add_attrs+0x64/0x3f0 drivers/base/core.c:2901
 device_add+0x37a/0x790 drivers/base/core.c:3645
 netdev_register_kobject+0x109/0x230 net/core/net-sysfs.c:2343
 register_netdevice+0xaaf/0x1160 net/core/dev.c:11423
 macvlan_common_newlink+0xa03/0xbe0 drivers/net/macvlan.c:1554
 macvlan_newlink+0x25/0x30 drivers/net/macvlan.c:1596
 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:2699
 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2753
 __sys_sendmsg net/socket.c:2785 [inline]
 __do_sys_sendmsg net/socket.c:2790 [inline]
 __se_sys_sendmsg net/socket.c:2788 [inline]
 __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2788
 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 0xffffc900000cf6f0 of 1 bytes by task 21317 on cpu 1:
 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_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
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x441/0x9f0 fs/sysfs/group.c:189
 internal_create_groups fs/sysfs/group.c:229 [inline]
 sysfs_create_groups+0x3f/0xf0 fs/sysfs/group.c:255
 setup_gid_attrs drivers/infiniband/core/sysfs.c:1118 [inline]
 ib_setup_port_attrs+0xe87/0x1400 drivers/infiniband/core/sysfs.c:1394
 add_one_compat_dev+0x297/0x390 drivers/infiniband/core/device.c:978
 rdma_dev_init_net+0x1b9/0x240 drivers/infiniband/core/device.c:1194
 ops_init+0x22a/0x2e0 net/core/net_namespace.c:137
 setup_net+0x9f/0x230 net/core/net_namespace.c:446
 copy_net_ns+0x310/0x450 net/core/net_namespace.c:579
 create_new_namespaces+0x20e/0x440 kernel/nsproxy.c:132
 copy_namespaces+0x1ad/0x210 kernel/nsproxy.c:195
 copy_process+0x10b1/0x2370 kernel/fork.c:2267
 kernel_clone+0x1c0/0x5f0 kernel/fork.c:2722
 __do_sys_clone kernel/fork.c:2863 [inline]
 __se_sys_clone kernel/fork.c:2847 [inline]
 __x64_sys_clone+0x143/0x180 kernel/fork.c:2847
 x64_sys_call+0x1222/0x3020 arch/x86/include/generated/asm/syscalls_64.h:57
 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

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 21317 Comm: syz.3.4732 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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