[PATCH 3.16 240/410] crypto: s5p-sss - Fix kernel Oops in AES-ECB mode

[Ben Hutchings]

3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Kamil Konieczny <k.konieczny@xxxxxxxxxxxxxxxxxxx>

commit c927b080c67e3e97193c81fc1d27f4251bf4e036 upstream.

In AES-ECB mode crypt is done with key only, so any use of IV
can cause kernel Oops. Use IV only in AES-CBC and AES-CTR.

Signed-off-by: Kamil Konieczny <k.konieczny@xxxxxxxxxxxxxxxxxxx>
Reported-by: Anand Moon <linux.amoon@xxxxxxxxx>
Reviewed-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Tested-by: Anand Moon <linux.amoon@xxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/crypto/s5p-sss.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/drivers/crypto/s5p-sss.c
+++ b/drivers/crypto/s5p-sss.c
@@ -426,15 +426,21 @@ static void s5p_aes_crypt_start(struct s
 	uint32_t                    aes_control;
 	int                         err;
 	unsigned long               flags;
+	u8 *iv;
 
 	aes_control = SSS_AES_KEY_CHANGE_MODE;
 	if (mode & FLAGS_AES_DECRYPT)
 		aes_control |= SSS_AES_MODE_DECRYPT;
 
-	if ((mode & FLAGS_AES_MODE_MASK) == FLAGS_AES_CBC)
+	if ((mode & FLAGS_AES_MODE_MASK) == FLAGS_AES_CBC) {
 		aes_control |= SSS_AES_CHAIN_MODE_CBC;
-	else if ((mode & FLAGS_AES_MODE_MASK) == FLAGS_AES_CTR)
+		iv = req->info;
+	} else if ((mode & FLAGS_AES_MODE_MASK) == FLAGS_AES_CTR) {
 		aes_control |= SSS_AES_CHAIN_MODE_CTR;
+		iv = req->info;
+	} else {
+		iv = NULL; /* AES_ECB */
+	}
 
 	if (dev->ctx->keylen == AES_KEYSIZE_192)
 		aes_control |= SSS_AES_KEY_SIZE_192;
@@ -465,7 +471,7 @@ static void s5p_aes_crypt_start(struct s
 		goto outdata_error;
 
 	SSS_AES_WRITE(dev, AES_CONTROL, aes_control);
-	s5p_set_aes(dev, dev->ctx->aes_key, req->info, dev->ctx->keylen);
+	s5p_set_aes(dev, dev->ctx->aes_key, iv, dev->ctx->keylen);
 
 	s5p_set_dma_indata(dev,  req->src);
 	s5p_set_dma_outdata(dev, req->dst);