[PATCH 4/4] crypto: ecc - Streamline alloc_point and remove {alloc,free}_digits_space

[Jonas Rebmann <jre@pengutronix.de>]

From: Thorsten Blum <thorsten.blum@linux.dev>

Check 'ndigits' before allocating 'struct ecc_point' to return early if
needed. Inline the code from and remove ecc_alloc_digits_space() and
ecc_free_digits_space(), respectively.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from linux commit c66e0a273f223fe38b8b72c034857622b0651482)
Reported-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Jonas Rebmann <jre@pengutronix.de>
---
 crypto/ecc.c | 29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

diff --git a/crypto/ecc.c b/crypto/ecc.c
index a228ae1a66..b6abdbee67 100644
--- a/crypto/ecc.c
+++ b/crypto/ecc.c
@@ -1,4 +1,4 @@
-// SPDX-Comment: Origin-URL: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/crypto/ecc.c?id=b16510a530d1e6ab9683f04f8fb34f2e0f538275
+// SPDX-Comment: Origin-URL: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/crypto/ecc.c?id=d6ea871d73abbb6a1e00e71ed5762e394d06cb2b
 /*
  * Copyright (c) 2013, 2014 Kenneth MacKay. All rights reserved.
  * Copyright (c) 2019 Vitaly Chikunov <vt@altlinux.org>
@@ -78,33 +78,24 @@ void ecc_digits_from_bytes(const u8 *in, unsigned int nbytes,
 }
 EXPORT_SYMBOL(ecc_digits_from_bytes);
 
-static u64 *ecc_alloc_digits_space(unsigned int ndigits)
+struct ecc_point *ecc_alloc_point(unsigned int ndigits)
 {
-	size_t len = ndigits * sizeof(u64);
+	struct ecc_point *p;
+	size_t ndigits_sz;
 
-	if (!len)
+	if (!ndigits)
 		return NULL;
 
-	return kmalloc(len, GFP_KERNEL);
-}
-
-static void ecc_free_digits_space(u64 *space)
-{
-	kfree_sensitive(space);
-}
-
-struct ecc_point *ecc_alloc_point(unsigned int ndigits)
-{
-	struct ecc_point *p = kmalloc(sizeof(*p), GFP_KERNEL);
-
+	p = kmalloc(sizeof(*p), GFP_KERNEL);
 	if (!p)
 		return NULL;
 
-	p->x = ecc_alloc_digits_space(ndigits);
+	ndigits_sz = ndigits * sizeof(u64);
+	p->x = kmalloc(ndigits_sz, GFP_KERNEL);
 	if (!p->x)
 		goto err_alloc_x;
 
-	p->y = ecc_alloc_digits_space(ndigits);
+	p->y = kmalloc(ndigits_sz, GFP_KERNEL);
 	if (!p->y)
 		goto err_alloc_y;
 
@@ -113,7 +104,7 @@ struct ecc_point *ecc_alloc_point(unsigned int ndigits)
 	return p;
 
 err_alloc_y:
-	ecc_free_digits_space(p->x);
+	kfree(p->x);
 err_alloc_x:
 	kfree(p);
 	return NULL;

-- 
2.54.0.129.g3edf2eeba9