[PATCH] crypto: sun8i-ss: Fix memory leak of object d when dma_iv fails to map

Colin King
2021-03-02T19:57:30Z

From: Colin Ian King <colin.king@canonical.com>

In the case where the dma_iv mapping fails, the return error path leaks
the memory allocated to object d. Fix this by adding a new error return
label and jumping to this to ensure d is free'd before the return.

Addresses-Coverity: ("Resource leak")
Fixes: ac2614d721de ("crypto: sun8i-ss - Add support for the PRNG")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c
index 08a1473b2145..3191527928e4 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c
@@ -103,7 +103,8 @@ int sun8i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
dma_iv = dma_map_single(ss->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);
if (dma_mapping_error(ss->dev, dma_iv)) {
dev_err(ss->dev, "Cannot DMA MAP IV\n");
- return -EFAULT;
+ err = -EFAULT;
+ goto err_free;
}

dma_dst = dma_map_single(ss->dev, d, todo, DMA_FROM_DEVICE);
@@ -167,6 +168,7 @@ int sun8i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
memcpy(ctx->seed, d + dlen, ctx->slen);
}
memzero_explicit(d, todo);
+err_free:
kfree(d);

return err;
--
2.30.0