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BUG: KCSAN: data-race in rwsem_down_write_slowpath / rwsem_down_write_slowpath

write to 0xffffc900013cba40 of 1 bytes by task 6253 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_activate+0x50/0x220 fs/kernfs/dir.c:1463
 kernfs_add_one+0x212/0x280 fs/kernfs/dir.c:869
 __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
 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
 unshare_nsproxy_namespaces+0x115/0x150 kernel/nsproxy.c:234
 ksys_unshare+0x402/0x740 kernel/fork.c:3245
 __do_sys_unshare kernel/fork.c:3319 [inline]
 __se_sys_unshare kernel/fork.c:3317 [inline]
 __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3317
 x64_sys_call+0x1cef/0x3020 arch/x86/include/generated/asm/syscalls_64.h:273
 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 0xffffc900013cba40 of 1 bytes by task 6217 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
 sysfs_remove_file_ns+0x3a/0x50 fs/sysfs/file.c:512
 sysfs_remove_file include/linux/sysfs.h:780 [inline]
 device_remove_file drivers/base/core.c:3072 [inline]
 device_remove_attrs+0xee/0x1a0 drivers/base/core.c:2973
 device_del+0x361/0x790 drivers/base/core.c:3894
 netdev_unregister_kobject+0x24d/0x270 net/core/net-sysfs.c:2314
 unregister_netdevice_many_notify+0x128b/0x1650 net/core/dev.c:12453
 unregister_netdevice_many+0x19/0x20 net/core/dev.c:12481
 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
 ops_undo_list+0x21d/0x420 net/core/net_namespace.c:248
 setup_net+0x1f2/0x230 net/core/net_namespace.c:462
 copy_net_ns+0x310/0x450 net/core/net_namespace.c:579
 create_new_namespaces+0x20e/0x440 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x115/0x150 kernel/nsproxy.c:234
 ksys_unshare+0x402/0x740 kernel/fork.c:3245
 __do_sys_unshare kernel/fork.c:3319 [inline]
 __se_sys_unshare kernel/fork.c:3317 [inline]
 __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3317
 x64_sys_call+0x1cef/0x3020 arch/x86/include/generated/asm/syscalls_64.h:273
 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: 0 UID: 0 PID: 6217 Comm: syz.3.587 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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