From: Jan-Simon Möller <dl...@gmx.de>

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using an char array.

The new code can be compiled with both gcc and clang.

struct shash_desc contains a flexible array member member ctx declared with
CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning
of the array declared after struct shash_desc with long long.

No trailing padding is required because it is not a struct type that can
be used in an array.

The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long long
as would be the case for a struct containing a member with
CRYPTO_MINALIGN_ATTR.

Signed-off-by: Jan-Simon Möller <dl...@gmx.de>
Signed-off-by: Behan Webster <beh...@converseincode.com>
---
 drivers/crypto/ccp/ccp-crypto-sha.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c 
b/drivers/crypto/ccp/ccp-crypto-sha.c
index 873f234..29f9fda 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -198,10 +198,11 @@ static int ccp_sha_setkey(struct crypto_ahash *tfm, const 
u8 *key,
 {
        struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
        struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
-       struct {
-               struct shash_desc sdesc;
-               char ctx[crypto_shash_descsize(shash)];
-       } desc;
+
+       char desc[sizeof(struct shash_desc) +
+               crypto_shash_descsize(shash)] CRYPTO_MINALIGN_ATTR;
+       struct shash_desc *sdesc = (struct shash_desc *)desc;
+
        unsigned int block_size = crypto_shash_blocksize(shash);
        unsigned int digest_size = crypto_shash_digestsize(shash);
        int i, ret;
@@ -216,11 +217,11 @@ static int ccp_sha_setkey(struct crypto_ahash *tfm, const 
u8 *key,
 
        if (key_len > block_size) {
                /* Must hash the input key */
-               desc.sdesc.tfm = shash;
-               desc.sdesc.flags = crypto_ahash_get_flags(tfm) &
+               sdesc->tfm = shash;
+               sdesc->flags = crypto_ahash_get_flags(tfm) &
                        CRYPTO_TFM_REQ_MAY_SLEEP;
 
-               ret = crypto_shash_digest(&desc.sdesc, key, key_len,
+               ret = crypto_shash_digest(sdesc, key, key_len,
                                          ctx->u.sha.key);
                if (ret) {
                        crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
-- 
1.9.1

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