From c05ac449442dd214e262057a3a49c368e224c384 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski <linux@dominikbrodowski.net> Date: Mon, 24 Jan 2022 21:29:48 +0100 Subject: [PATCH] hwrng: core - use rng_fillbuf in add_early_randomness() Using rng_buffer in add_early_randomness() may race with rng_dev_read(). Use rng_fillbuf instead, as it is otherwise only used within the kernel by hwrng_fillfn() and therefore never exposed to userspace. Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> --- drivers/char/hw_random/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index c2d260b5dd921..89891ac87af00 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -66,10 +66,10 @@ static void add_early_randomness(struct hwrng *rng) int bytes_read; mutex_lock(&reading_mutex); - bytes_read = rng_get_data(rng, rng_buffer, 32, 0); + bytes_read = rng_get_data(rng, rng_fillbuf, 32, 0); mutex_unlock(&reading_mutex); if (bytes_read > 0) - add_device_randomness(rng_buffer, bytes_read); + add_device_randomness(rng_fillbuf, bytes_read); } static inline void cleanup_rng(struct kref *kref) -- GitLab