==================================================================
BUG: KCSAN: data-race in ep_poll / ep_poll_callback

write to 0xffff888126b6b1d0 of 8 bytes by task 8912 on cpu 1:
 list_add_tail_lockless fs/eventpoll.c:1158 [inline]
 ep_poll_callback+0x5f2/0x6c0 fs/eventpoll.c:1248
 __wake_up_common+0x76/0x180 kernel/sched/wait.c:93
 __wake_up_common_lock+0x77/0xb0 kernel/sched/wait.c:123
 pipe_write+0xaa0/0xd40 fs/pipe.c:611
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write+0x303/0x400 fs/read_write.c:484
 __vfs_write+0x9e/0xb0 fs/read_write.c:497
 vfs_write fs/read_write.c:559 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:543
 ksys_write+0x16a/0x1a0 fs/read_write.c:612
 __do_sys_write fs/read_write.c:624 [inline]
 __se_sys_write fs/read_write.c:621 [inline]
 __x64_sys_write+0x49/0x60 fs/read_write.c:621
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888126b6b1d0 of 8 bytes by task 8921 on cpu 0:
 list_empty_careful include/linux/list.h:300 [inline]
 ep_events_available fs/eventpoll.c:379 [inline]
 ep_poll+0x5ad/0x910 fs/eventpoll.c:1902
 do_epoll_wait+0x15a/0x180 fs/eventpoll.c:2320
 __do_sys_epoll_pwait fs/eventpoll.c:2351 [inline]
 __se_sys_epoll_pwait fs/eventpoll.c:2337 [inline]
 __x64_sys_epoll_pwait+0xc6/0x170 fs/eventpoll.c:2337
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8921 Comm: syz-fuzzer Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================