crypto: crct10dif-neon - fix use via crypto_shash_digest()

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I569U8
CVE: NA

Reference: https://lore.kernel.org/lkml/20190609164147.971147667@linuxfoundation.org/

--------------------------------

The digest() hook relies on a crc value from the shash_desc context.
However, this context is not initialized while digest() hook is called,
and an arbitrary value is read causing the algorithm generating wrong
result.

This patch fixes this issue by passing a 0 as the initial crc value in
the digest() hook.
Signed-off-by: NGUO Zihua <guozihua@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Reviewed-by: NWang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/crypto/crct10dif-neon_glue.c

@@ -55,10 +55,10 @@ static int chksum_final(struct shash_desc *desc, u8 *out)
 	return 0;
 }
 
-static int __chksum_finup(__u16 *crcp, const u8 *data, unsigned int len,
+static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len,
 			u8 *out)
 {
-	*(__u16 *)out = crc_t10dif_neon(*crcp, data, len);
+	*(__u16 *)out = crc_t10dif_neon(crc, data, len);
 	return 0;
 }
 
@@ -67,15 +67,13 @@ static int chksum_finup(struct shash_desc *desc, const u8 *data,
 {
 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
 
-	return __chksum_finup(&ctx->crc, data, len, out);
+	return __chksum_finup(ctx->crc, data, len, out);
 }
 
 static int chksum_digest(struct shash_desc *desc, const u8 *data,
 			 unsigned int length, u8 *out)
 {
-	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
-
-	return __chksum_finup(&ctx->crc, data, length, out);
+	return __chksum_finup(0, data, length, out);
 }
 
 static struct shash_alg alg = {