In the Linux kernel, the following vulnerability has been resolved:
crypto: qcom-rng - Remove crypto_rng interface
qcom-rng.c exposes the same hardware through two completely separate
interfaces, crypto_rng and hwrng. However, the implementation of this
is buggy because it permits generation operations from these interfaces
to run concurrently with each other, accessing the same registers. That
is, qcom_rng_generate() synchronizes with itself but not with
qcom_hwrng_read(). This results in potential repetition of output from
the RNG, output of non-random values, etc.
Fortunately, there's actually no point in hardware RNG drivers
implementing the crypto_rng interface. It's not actually used by
anything besides the "rng" algorithm type of AF_ALG, which in turn is
not actually used in practice. Other crypto_rng hardware drivers are
likewise being phased out, leaving just the hwrng support.
Thus, remove it to simplify the code and avoid conflict (and confusion)
with the hwrng interface which is the one that actually matters.