KCSAN: data-race in do_recvmmsg / do

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in do_recvmmsg / do_recvmmsg net				1	1296d	1296d	0/28	auto-closed as invalid on 2021/06/21 21:01

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BUG: KCSAN: data-race in do_recvmmsg / do_recvmmsg

write to 0xffff88810491b0e0 of 4 bytes by task 24891 on cpu 0:
 do_recvmmsg+0x653/0x710 net/socket.c:2912
 __sys_recvmmsg net/socket.c:2935 [inline]
 __do_sys_recvmmsg net/socket.c:2958 [inline]
 __se_sys_recvmmsg net/socket.c:2951 [inline]
 __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951
 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

write to 0xffff88810491b0e0 of 4 bytes by task 24875 on cpu 1:
 do_recvmmsg+0x653/0x710 net/socket.c:2912
 __sys_recvmmsg net/socket.c:2935 [inline]
 __do_sys_recvmmsg net/socket.c:2958 [inline]
 __se_sys_recvmmsg net/socket.c:2951 [inline]
 __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951
 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 -> 0x0000005a

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24875 Comm: syz-executor.2 Not tainted 6.3.0-rc6-syzkaller-00035-g0bcc40255504 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
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