random: fix the RNDRESEEDCRNG ioctl

commit 11a0b5e0ec8c13bef06f7414f9e914506140d5cb upstream.

The RNDRESEEDCRNG ioctl reseeds the primary_crng from itself, which
doesn't make sense.  Reseed it from the input_pool instead.

Fixes: d848e5f8e1eb ("random: add new ioctl RNDRESEEDCRNG")
Cc: stable@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20210112192818.69921-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 2a41b21..f462b9d 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1972,7 +1972,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
                        return -EPERM;
                if (crng_init < 2)
                        return -ENODATA;
-               crng_reseed(&primary_crng, NULL);
+               crng_reseed(&primary_crng, &input_pool);
                crng_global_init_time = jiffies - 1;
                return 0;
        default: