From: Andrei Botila <andrei.botila@nxp.com>
Date: Tue, 22 Sep 2020 19:03:25 +0300
Subject: crypto: caam - add xts check for block length equal to zero
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Git-commit: 297b931c2a3cada230d8b84432ee982fc68cf76a
Patch-mainline: v5.10-rc1
References: jsc#SLE-16106

XTS should not return succes when dealing with block length equal to zero.
This is different than the rest of the skcipher algorithms.

Fixes: 31bb2f0da1b50 ("crypto: caam - check zero-length input")
Cc: <stable@vger.kernel.org> # v5.4+
Signed-off-by: Andrei Botila <andrei.botila@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 drivers/crypto/caam/caamalg.c     |    7 ++++++-
 drivers/crypto/caam/caamalg_qi.c  |    7 ++++++-
 drivers/crypto/caam/caamalg_qi2.c |   14 ++++++++++++--
 3 files changed, 24 insertions(+), 4 deletions(-)

--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -1806,7 +1806,12 @@ static inline int skcipher_crypt(struct
 	u32 *desc;
 	int ret = 0;
 
-	if (!req->cryptlen)
+	/*
+	 * XTS is expected to return an error even for input length = 0
+	 * Note that the case input length < block size will be caught during
+	 * HW offloading and return an error.
+	 */
+	if (!req->cryptlen && !ctx->fallback)
 		return 0;
 
 	if (ctx->fallback && (xts_skcipher_ivsize(req) ||
--- a/drivers/crypto/caam/caamalg_qi.c
+++ b/drivers/crypto/caam/caamalg_qi.c
@@ -1427,7 +1427,12 @@ static inline int skcipher_crypt(struct
 	struct caam_ctx *ctx = crypto_skcipher_ctx(skcipher);
 	int ret;
 
-	if (!req->cryptlen)
+	/*
+	 * XTS is expected to return an error even for input length = 0
+	 * Note that the case input length < block size will be caught during
+	 * HW offloading and return an error.
+	 */
+	if (!req->cryptlen && !ctx->fallback)
 		return 0;
 
 	if (ctx->fallback && (xts_skcipher_ivsize(req) ||
--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -1498,7 +1498,12 @@ static int skcipher_encrypt(struct skcip
 	struct caam_request *caam_req = skcipher_request_ctx(req);
 	int ret;
 
-	if (!req->cryptlen)
+	/*
+	 * XTS is expected to return an error even for input length = 0
+	 * Note that the case input length < block size will be caught during
+	 * HW offloading and return an error.
+	 */
+	if (!req->cryptlen && !ctx->fallback)
 		return 0;
 
 	if (ctx->fallback && (xts_skcipher_ivsize(req) ||
@@ -1542,7 +1547,12 @@ static int skcipher_decrypt(struct skcip
 	struct caam_request *caam_req = skcipher_request_ctx(req);
 	int ret;
 
-	if (!req->cryptlen)
+	/*
+	 * XTS is expected to return an error even for input length = 0
+	 * Note that the case input length < block size will be caught during
+	 * HW offloading and return an error.
+	 */
+	if (!req->cryptlen && !ctx->fallback)
 		return 0;
 
 	if (ctx->fallback && (xts_skcipher_ivsize(req) ||