In the Linux kernel, the following vulnerability has been resolved:
crypto: sun4i-ss - Remove insecure and unused rng_alg
Remove sun4i_ss_rng, as it is insecure and unused:
- It has multiple vulnerabilities. sun4i_ss_prng_seed() is missing
locking and has a buffer overflow. sun4i_ss_prng_generate() fails to
fill the entire buffer with cryptographic random bytes, because it
rounds the destination length down and also doesn't actually wait for
the hardware to be ready before pulling bytes from it.
- No user of this code is known. It's usable only theoretically via the
"rng" algorithm type of AF_ALG. But userspace actually just uses the
actual Linux RNG (/dev/random etc) instead.
And rng_algs don't
contribute entropy to the actual Linux RNG either. (This may have
been confused with hwrng, which does contribute entropy.)
The sun4i_ss_prng_seed() buffer overflow was reported by Tianchu Chen
and discovered by Atuin - Automated Vulnerability Discovery Engine
There's no point in fixing all these vulnerabilities individually when
this is unused code, so let's just remove it.
Attack Parameters
Impact Assessment
CVSS Vector v3.1