syzbot

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

write to 0xffffc90000f6bac8 of 1 bytes by task 4427 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+0xab/0xc0 kernel/locking/rwsem.c:1632
 kernfs_add_one+0x5a/0x290 fs/kernfs/dir.c:825
 __kernfs_create_file+0x145/0x180 fs/kernfs/file.c:1079
 sysfs_add_file_mode_ns+0x132/0x1b0 fs/sysfs/file.c:316
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x43e/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+0xee7/0x1480 drivers/infiniband/core/sysfs.c:1394
 add_one_compat_dev+0x297/0x390 drivers/infiniband/core/device.c:979
 add_compat_devs drivers/infiniband/core/device.c:1037 [inline]
 enable_device_and_get+0x1cd/0x260 drivers/infiniband/core/device.c:1347
 ib_register_device+0xb36/0xcb0 drivers/infiniband/core/device.c:1468
 rxe_register_device+0x175/0x190 drivers/infiniband/sw/rxe/rxe_verbs.c:1543
 rxe_add+0x8e2/0x900 drivers/infiniband/sw/rxe/rxe.c:217
 rxe_net_add+0x62/0xb0 drivers/infiniband/sw/rxe/rxe_net.c:625
 rxe_newlink+0xdd/0x1a0 drivers/infiniband/sw/rxe/rxe.c:243
 nldev_newlink+0x3a8/0x430 drivers/infiniband/core/nldev.c:1816
 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 rdma_nl_rcv+0x439/0x570 drivers/infiniband/core/netlink.c:259
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x5a7/0x680 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x5be/0x6f0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:775 [inline]
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0x532/0x580 net/socket.c:2684
 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2773
 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+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffc90000f6bac8 of 1 bytes by task 3288 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+0xab/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]
 sysfs_remove_link+0x39/0x50 fs/sysfs/symlink.c:152
 device_remove_class_symlinks+0xcd/0x120 drivers/base/core.c:3544
 device_del+0x289/0x790 drivers/base/core.c:3947
 drop_partition block/partitions/core.c:280 [inline]
 bdev_disk_changed+0x1a0/0xe20 block/partitions/core.c:676
 __loop_clr_fd drivers/block/loop.c:1160 [inline]
 lo_release+0x331/0x430 drivers/block/loop.c:1747
 bdev_release+0x375/0x3d0 block/bdev.c:-1
 blkdev_release+0x15/0x20 block/fops.c:680
 __fput+0x29e/0x630 fs/file_table.c:512
 fput_close_sync+0xad/0x190 fs/file_table.c:617
 __do_sys_close fs/open.c:1511 [inline]
 __se_sys_close fs/open.c:1496 [inline]
 __x64_sys_close+0x55/0xf0 fs/open.c:1496
 x64_sys_call+0x275d/0x3020 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 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: 3288 Comm: udevd Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
==================================================================
udevd[3288]: inotify_add_watch(7, /dev/loop2p2, 10) failed: No such file or directory
udevd[3288]: inotify_add_watch(7, /dev/loop2p15, 10) failed: No such file or directory