syzbot

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BUG: KCSAN: data-race in kcm_recvmsg / kcm_recvmsg

read-write to 0xffff888102fdeb40 of 8 bytes by task 20036 on cpu 0:
 kcm_recvmsg+0x1f9/0x290 net/kcm/kcmsock.c:1010
 sock_recvmsg_nosec+0x107/0x140 net/socket.c:1046
 ____sys_recvmsg+0x271/0x280 net/socket.c:2801
 ___sys_recvmsg net/socket.c:2845 [inline]
 do_recvmmsg+0x2eb/0x720 net/socket.c:2939
 __sys_recvmmsg net/socket.c:3018 [inline]
 __do_sys_recvmmsg net/socket.c:3041 [inline]
 __se_sys_recvmmsg net/socket.c:3034 [inline]
 __x64_sys_recvmmsg+0xe2/0x170 net/socket.c:3034
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

read-write to 0xffff888102fdeb40 of 8 bytes by task 20037 on cpu 1:
 kcm_recvmsg+0x1f9/0x290 net/kcm/kcmsock.c:1010
 sock_recvmsg_nosec+0x107/0x140 net/socket.c:1046
 ____sys_recvmsg+0x271/0x280 net/socket.c:2801
 ___sys_recvmsg net/socket.c:2845 [inline]
 do_recvmmsg+0x2eb/0x720 net/socket.c:2939
 __sys_recvmmsg net/socket.c:3018 [inline]
 __do_sys_recvmmsg net/socket.c:3041 [inline]
 __se_sys_recvmmsg net/socket.c:3034 [inline]
 __x64_sys_recvmmsg+0xe2/0x170 net/socket.c:3034
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

value changed: 0x00000000000079e8 -> 0x00000000000079ec

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20037 Comm: syz-executor.0 Tainted: G        W          6.8.0-syzkaller-09791-ge5eb28f6d1af #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
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