syzbot

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BUG: KCSAN: data-race in do_sys_poll / pollwake

write to 0xffffc90000c37c30 of 4 bytes by task 10500 on cpu 1:
 __pollwake fs/select.c:198 [inline]
 pollwake+0xbe/0x110 fs/select.c:218
 __wake_up_common+0xb3/0x130 kernel/sched/wait.c:107
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up+0x7e/0xc0 kernel/sched/wait.c:160
 ep_poll_safewake fs/eventpoll.c:541 [inline]
 ep_poll_callback+0x49c/0x5a0 fs/eventpoll.c:1252
 __wake_up_common+0xb3/0x130 kernel/sched/wait.c:107
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up+0x7e/0xc0 kernel/sched/wait.c:160
 unix_dgram_peer_wake_relay+0xd4/0xf0 net/unix/af_unix.c:447
 __wake_up_common+0xb3/0x130 kernel/sched/wait.c:107
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up_sync_key+0x82/0xc0 kernel/sched/wait.c:208
 __unix_dgram_recvmsg+0x3c3/0x870 net/unix/af_unix.c:2479
 unix_dgram_recvmsg+0x7b/0x90 net/unix/af_unix.c:2549
 sock_recvmsg_nosec+0x4c/0x80 net/socket.c:1019
 ____sys_recvmsg+0x2db/0x310 net/socket.c:2720
 ___sys_recvmsg net/socket.c:2764 [inline]
 do_recvmmsg+0x2e5/0x710 net/socket.c:2858
 __sys_recvmmsg net/socket.c:2937 [inline]
 __do_sys_recvmmsg net/socket.c:2960 [inline]
 __se_sys_recvmmsg net/socket.c:2953 [inline]
 __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2953
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffffc90000c37c30 of 4 bytes by task 10509 on cpu 0:
 poll_schedule_timeout fs/select.c:243 [inline]
 do_poll fs/select.c:965 [inline]
 do_sys_poll+0x9a2/0xbf0 fs/select.c:1015
 __do_sys_ppoll fs/select.c:1121 [inline]
 __se_sys_ppoll+0x1af/0x1f0 fs/select.c:1101
 __x64_sys_ppoll+0x67/0x80 fs/select.c:1101
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10509 Comm: syz-executor.2 Not tainted 6.4.0-rc5-syzkaller-00024-g5f63595ebd82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
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