[PATCH] crypto: fsl - Fix RNG generation for lengths greater than 16 bytes

[Pawel Kochanowski]

From: Gabriel Nesteruk <gnesteruk at sii.pl>

Reinitialize the descriptor for each RNG job, as it
may be modified by run_descriptor_jr().
Failing to do so can result in memory corruption when
dm_rng_read() is called a second time on NXP devices
with CONFIG_SYS_FSL_SEC_BE enabled.

Signed-off-by: Gabriel Nesteruk <gnesteruk at sii.pl>
Signed-off-by: Pawel Kochanowski <pkochanowski at sii.pl>
---
 drivers/crypto/fsl/rng.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/crypto/fsl/rng.c b/drivers/crypto/fsl/rng.c
index 06364948052..440b26e3c94 100644
--- a/drivers/crypto/fsl/rng.c
+++ b/drivers/crypto/fsl/rng.c
@@ -27,8 +27,14 @@ struct caam_rng_priv {
 static int caam_rng_read_one(struct caam_rng_priv *priv)
 {
 	int size = ALIGN(CAAM_RNG_MAX_FIFO_STORE_SIZE, ARCH_DMA_MINALIGN);
+	ulong rng_desc_size = ALIGN(CAAM_RNG_DESC_LEN, ARCH_DMA_MINALIGN);
 	int ret;
 
+	inline_cnstr_jobdesc_rng(priv->desc, priv->data,
+		CAAM_RNG_MAX_FIFO_STORE_SIZE);
+	flush_dcache_range((unsigned long)priv->desc,
+	  (unsigned long)priv->desc + rng_desc_size);
+
 	ret = run_descriptor_jr(priv->desc);
 	if (ret < 0)
 		return -EIO;
@@ -63,14 +69,6 @@ static int caam_rng_read(struct udevice *dev, void *data, size_t len)
 
 static int caam_rng_probe(struct udevice *dev)
 {
-	struct caam_rng_priv *priv = dev_get_priv(dev);
-	ulong size = ALIGN(CAAM_RNG_DESC_LEN, ARCH_DMA_MINALIGN);
-
-	inline_cnstr_jobdesc_rng(priv->desc, priv->data,
-				 CAAM_RNG_MAX_FIFO_STORE_SIZE);
-	flush_dcache_range((unsigned long)priv->desc,
-			   (unsigned long)priv->desc + size);
-
 	return 0;
 }
 
-- 
2.43.0