r0 = socket$inet6(0xa, 0x3, 0x5)
r1 = dup2(r0, r0)
setsockopt$inet6_mreq(r1, 0x29, 0x1b, &(0x7f00000001c0)={@empty}, 0x14)
r2 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000000)='net/anycast6\x00')
preadv(r2, &(0x7f0000000040)=[{&(0x7f0000000200)=""/257, 0x101}], 0x1, 0x3fc, 0x0)