==================================================================
BUG: KCSAN: data-race in fasync_remove_entry / kill_fasync

write to 0xffff88804d642300 of 8 bytes by task 22139 on cpu 1:
 fasync_remove_entry+0xba/0x120 fs/fcntl.c:882
 fasync_helper+0xcf/0xdc fs/fcntl.c:981
 perf_fasync+0x6c/0xa0 kernel/events/core.c:6002
 __fput+0x46a/0x520 fs/file_table.c:277
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88804d642300 of 8 bytes by interrupt on cpu 0:
 kill_fasync+0x3f/0x180 fs/fcntl.c:1019
 perf_event_wakeup+0x11f/0x160 kernel/events/core.c:6042
 perf_pending_event+0x12d/0x170 kernel/events/core.c:6098
 irq_work_run_list+0x136/0x190 kernel/irq_work.c:156
 irq_work_run+0x48/0xa0 kernel/irq_work.c:172
 smp_irq_work_interrupt+0x3f/0x100 arch/x86/kernel/irq_work.c:21
 irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:860
 format_decode+0xf1/0xb10 lib/vsprintf.c:2310
 vsnprintf+0xc9/0xb40 lib/vsprintf.c:2526
 snprintf+0x6f/0xa0 lib/vsprintf.c:2707
 __dev_alloc_name net/core/dev.c:1117 [inline]
 dev_alloc_name_ns+0x1bf/0x380 net/core/dev.c:1145
 dev_get_valid_name+0x75/0x100 net/core/dev.c:1180
 register_netdevice+0xfa/0xad0 net/core/dev.c:9235
 br_dev_newlink+0x33/0xf0 net/bridge/br_netlink.c:1315
 __rtnl_newlink+0xc8d/0x1090 net/core/rtnetlink.c:3305
 rtnl_newlink+0x63/0x90 net/core/rtnetlink.c:3363
 rtnetlink_rcv_msg+0x1d3/0x500 net/core/rtnetlink.c:5424
 netlink_rcv_skb+0xb0/0x260 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x26/0x30 net/core/rtnetlink.c:5442
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x3a6/0x4d0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x4d3/0x8b0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:659
 ____sys_sendmsg+0x49d/0x4d0 net/socket.c:2330
 ___sys_sendmsg+0xb5/0x100 net/socket.c:2384
 __sys_sendmsg+0xa0/0x160 net/socket.c:2417
 __do_sys_sendmsg net/socket.c:2426 [inline]
 __se_sys_sendmsg net/socket.c:2424 [inline]
 __x64_sys_sendmsg+0x51/0x70 net/socket.c:2424
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 22244 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================