r0 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000000)='mountinfo\x00')
r1 = socket$inet6_tcp(0xa, 0x1, 0x0)
r2 = dup2(r1, r0)
setsockopt$inet6_MCAST_JOIN_GROUP(r2, 0x29, 0x13, &(0x7f0000000200)={0x1, {{0xa, 0x0, 0x0, @mcast1}}}, 0x88)