[PATCH] crypto: ansi_cprng: fix cipher leak in cprng_init error path

[Haotian Zhang <vulab@iscas.ac.cn>]

In the commit referenced by the Fixes tag, crypto_alloc_cipher()
was moved from reset_prng_context() to cprng_init(). However,
this approach does not account for the error path: when
reset_prng_context() fails, crypto_free_cipher() is never called,
resulting in a resource leak.

Free the allocated cipher before returning on reset_prng_context()
failure.

Fixes: fd09d7facb7c ("crypto: ansi_prng - alloc cipher just in init")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
---
 crypto/ansi_cprng.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index 153523ce6076..6cf505bcf794 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -329,8 +329,10 @@ static int cprng_init(struct crypto_tfm *tfm)
 		return PTR_ERR(ctx->tfm);
 	}
 
-	if (reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL) < 0)
+	if (reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL) < 0) {
+		crypto_free_cipher(ctx->tfm);
 		return -EINVAL;
+	}
 
 	/*
 	 * after allocation, we should always force the user to reset
-- 
2.50.1.windows.1