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BUG: KCSAN: data-race in rawv6_sendmsg / sock_bindtoindex

write to 0xffff88811eb49ad4 of 4 bytes by task 27145 on cpu 1:
 sock_bindtoindex_locked net/core/sock.c:584 [inline]
 sock_bindtoindex+0x96/0x240 net/core/sock.c:603
 sock_setbindtodevice net/core/sock.c:651 [inline]
 sock_setsockopt+0x26a/0x1c80 net/core/sock.c:851
 __sys_setsockopt+0x223/0x390 net/socket.c:2123
 __do_sys_setsockopt net/socket.c:2143 [inline]
 __se_sys_setsockopt net/socket.c:2140 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2140
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811eb49ad4 of 4 bytes by task 27148 on cpu 0:
 rawv6_sendmsg+0x36e/0x1360 net/ipv6/raw.c:865
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:814
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 sock_write_iter+0x1a1/0x200 net/socket.c:999
 call_write_iter include/linux/fs.h:1868 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x608/0x690 fs/read_write.c:578
 ksys_write+0xce/0x180 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write fs/read_write.c:640 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:640
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 27148 Comm: syz-executor.2 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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