FAILED: patch "[PATCH] crypto: caam - add xts check for block length equal to zero" failed to apply to 5.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 297b931c2a3cada230d8b84432ee982fc68cf76a Mon Sep 17 00:00:00 2001
From: Andrei Botila <andrei.botila@nxp.com>
Date: Tue, 22 Sep 2020 19:03:25 +0300
Subject: [PATCH] crypto: caam - add xts check for block length equal to zero
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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>

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index a79b26f84169..e72aa3e2e065 100644
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -1787,7 +1787,12 @@ static inline int skcipher_crypt(struct skcipher_request *req, bool encrypt)
 	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) ||
diff --git a/drivers/crypto/caam/caamalg_qi.c b/drivers/crypto/caam/caamalg_qi.c
index 30aceaf325d7..efcc7cb050fc 100644
--- a/drivers/crypto/caam/caamalg_qi.c
+++ b/drivers/crypto/caam/caamalg_qi.c
@@ -1405,7 +1405,12 @@ static inline int skcipher_crypt(struct skcipher_request *req, bool encrypt)
 	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) ||
diff --git a/drivers/crypto/caam/caamalg_qi2.c b/drivers/crypto/caam/caamalg_qi2.c
index 255b818c82b2..4cbd7e834888 100644
--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -1472,7 +1472,12 @@ static int skcipher_encrypt(struct skcipher_request *req)
 	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) ||
@@ -1516,7 +1521,12 @@ static int skcipher_decrypt(struct skcipher_request *req)
 	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) ||