tree 02c332b7beb51b7ae8b91fea500c96ec89f023bb
parent 242dc3744148b1f930050140606c7e170b4704f7
author Jason A. Donenfeld <Jason@zx2c4.com> 1640812204 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1656150304 +0200

random: do not re-init if crng_reseed completes before primary init

commit 9c3ddde3f811aabbb83778a2a615bf141b4909ef upstream.

If the bootloader supplies sufficient material and crng_reseed() is called
very early on, but not too early that wqs aren't available yet, then we
might transition to crng_init==2 before rand_initialize()'s call to
crng_initialize_primary() made. Then, when crng_initialize_primary() is
called, if we're trusting the CPU's RDRAND instructions, we'll
needlessly reinitialize the RNG and emit a message about it. This is
mostly harmless, as numa_crng_init() will allocate and then free what it
just allocated, and excessive calls to invalidate_batched_entropy()
aren't so harmful. But it is funky and the extra message is confusing,
so avoid the re-initialization all together by checking for crng_init <
2 in crng_initialize_primary(), just as we already do in crng_reseed().

Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>