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BUG: KMSAN: uninit-value in memcmp lib/string.c:683 [inline]
BUG: KMSAN: uninit-value in bcmp+0xbf/0x1c0 lib/string.c:715
 memcmp lib/string.c:683 [inline]
 bcmp+0xbf/0x1c0 lib/string.c:715
 ____sys_sendmsg+0x813/0xe70 net/socket.c:2471
 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2530
 __sys_sendmmsg+0x40d/0xa40 net/socket.c:2616
 __do_sys_sendmmsg net/socket.c:2645 [inline]
 __se_sys_sendmmsg net/socket.c:2642 [inline]
 __x64_sys_sendmmsg+0xb8/0x120 net/socket.c:2642
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was stored to memory at:
 ____sys_sendmsg+0xbe8/0xe70 net/socket.c:2484
 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2530
 __sys_sendmmsg+0x40d/0xa40 net/socket.c:2616
 __do_sys_sendmmsg net/socket.c:2645 [inline]
 __se_sys_sendmmsg net/socket.c:2642 [inline]
 __x64_sys_sendmmsg+0xb8/0x120 net/socket.c:2642
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Local variable sin created at:
 udpv6_sendmsg+0x56/0x4430 net/ipv6/udp.c:1330
 inet6_sendmsg+0x101/0x180 net/ipv6/af_inet6.c:660

CPU: 1 PID: 5412 Comm: syz-executor.4 Not tainted 6.2.0-rc3-syzkaller-79343-ge919e2b1bc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
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