Brother Nasir Hussein had mentioned this in one of his posts, You can read that here regarding opinion of Malik about anal intercourse being allowed

I wont be translating all of it, rather giving jists from that

He writes:-

We find in Tafsir Dur e Manthur by Sayooti, that he wrote

وأخرج ابن جرير في كتاب النكاح من طريق ابن وهب عن مالك : أنه مباح

Ibn Jurair mentioned in his Kitab un Nikah with chain of Ibn Wahab from Malik who said It is allowed

[Tafsir Dur e Manthur, 1/266]

In this narration which has been mentioned by Sayooti, the narrator between Ibn Jurair and Ibn Wahab is missing. However, this is mentioned by Tibri in his book “Ikhtilaaf ul Fuqaha” while discussing the differences of opinion about anal intercourse. Tibri wrote

فقال مالك : لا بأس بأن يأتي الرجل إمرأته في دبرها كما يأتيها في قبلها “حدثنا بذلك يونس عن ابن وهب عنه

Malik said that there is no problem if a man comes in back part of his wife just like he comes in front part

[Ikhtilaaf ul Fuqaha, page 304, printed by Dar ul Kutb Ilmia, Beirut]

So, we see that the missing link is [يونس بن عبد الأعلى المصري ] Younas bin Abdul A’la al Misri. He is a thiqa narrator

Let me {Slave of Ahlubait} add that Dhabi wrote for him in Sair ul Alaam Nabala

يونس بن عبد الأعلى ( م ، س ، ق )

ابن ميسرة بن حفص بن حيان ، الإمام ، شيخ الإسلام ، أبو موسى الصدفي ، المصري المقرئ الحافظ ، وأمه فليحة بنت أبان التجيبية

Imam, Sheikh ul Islam, Hafiz

then he wrote

قال يحيى بن حسان التنيسي : يونسكم هذا ركن من أركان الإسلام .

وقال النسائي : ثقة .

وقال ابن أبي حاتم : سمعت أبي يوثقه ، ويرفع من شأنه .

وقال أبو حاتم : سمعت أبا الطاهر بن السرح ، يحث على يونس ، ويعظم شأنه .

وقال علي بن الحسن بن قديد : كان يحفظ الحديث . 

So, Yahya bin Hasan included him in Pillars of Islam; Ibn Abi Hatima, Nisai did his tautheeq.

[Online link]

And Abdullah bin Wahab,a narrator of Sheikhain, In view of Ibn Hajar, he was

ثقة حافظ عابد فقيه

And Dhabi had introduced him 

عبد الله بن وهب (ع)

ابن مسلم ، الإمام شيخ الإسلام أبو محمد الفهري ، مولاهم المصري الحافظ .

Hafiz Jasas, who is one of the Imams of Ahlusunnah, he said about this in his Ahkam ul Quran

قال أبو بكر المشهور عن مالك إباحة ذلك وأصحابه ينفون عنه هذه المقالة لقبحها وشناعتها وهي عنه أشهر من أن يندفع بنفيهم

Abu Bakr said: ‘It is well known that Malik allowed it but his companions deny it because it was a very nasty statement, in fact it is well known and cannot be denied by their denial

[Ahkam ul Quran, 2/40]

You can read more about Malik’s opinion here

And you can see the scans for what I have quoted in this article over here