Quote from: Pmalek on Today at 08:38:29 AM

The first link you shared, says that Linux doesn't rely on RDRAND by default when it generates entropy.

According to Linus Torvalds, it doesn't rely entirely on RdRand. But /dev/random does make use of it.

Quote from: https://en.wikipedia.org/wiki/RDRAND

Linus Torvalds dismissed concerns about the use of RDRAND in the Linux kernel and pointed out that it is not used as the only source of entropy for /dev/random, but rather used to improve the entropy by combining the values received from RDRAND with other sources of randomness.

You can also read this response by Linus, in which he pretty much sums up his concerns regarding RdRand: https://www.theregister.com/2013/09/10/torvalds_on_rrrand_nsa_gchq/. He's also clarifying that RdRand is one of the many inputs used:

Quote

However, as Torvalds pointed out in response to the petition RdRand is one of many inputs used by the Linux kernel’s pool to generate random characters.

The kernel chieftain wrote: “We use rdrand as _one_ of many inputs into the random pool, and we use it as a way to _improve_ that random pool. So even if rdrand were to be back-doored by the NSA, our use of rdrand actually improves the quality of the random numbers you get from /dev/random. Really short answer: you're ignorant.”

Quote from: Pmalek on Today at 08:38:29 AM

I guess it's harder to know its full impact on the close-source Windows.

We don't know with certainty: https://security.stackexchange.com/questions/195515/is-rdrand-used-in-a-safe-way-by-windows-10