[PATCH 2/5] crypto: mediatek: fix uninitialized value of gctx->textlen

[Vic Wu]

From: Ryder Lee <ryder....@mediatek.com>

Add a pre-computed text length to avoid uninitialized value in the check.

Fixes: e47270665b5f ("crypto: mediatek - Add empty messages check in GCM mode")
Signed-off-by: Ryder Lee <ryder....@mediatek.com>
Signed-off-by: Vic Wu <vic...@mediatek.com>
---
 drivers/crypto/mediatek/mtk-aes.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/mediatek/mtk-aes.c 
b/drivers/crypto/mediatek/mtk-aes.c
index 43fcc8b5..425d7f3f 100644
--- a/drivers/crypto/mediatek/mtk-aes.c
+++ b/drivers/crypto/mediatek/mtk-aes.c
@@ -896,14 +896,11 @@ static int mtk_aes_gcm_start(struct mtk_cryp *cryp, 
struct mtk_aes_rec *aes)
                aes->resume = mtk_aes_transfer_complete;
                /* Compute total process length. */
                aes->total = len + gctx->authsize;
-               /* Compute text length. */
-               gctx->textlen = req->cryptlen;
                /* Hardware will append authenticated tag to output buffer */
                scatterwalk_map_and_copy(tag, req->dst, len, gctx->authsize, 1);
        } else {
                aes->resume = mtk_aes_gcm_tag_verify;
                aes->total = len;
-               gctx->textlen = req->cryptlen - gctx->authsize;
        }
 
        return mtk_aes_gcm_dma(cryp, aes, req->src, req->dst, len);
@@ -915,19 +912,22 @@ static int mtk_aes_gcm_crypt(struct aead_request *req, 
u64 mode)
        struct mtk_aes_gcm_ctx *gctx = mtk_aes_gcm_ctx_cast(ctx);
        struct mtk_aes_reqctx *rctx = aead_request_ctx(req);
        struct mtk_cryp *cryp;
+       bool enc = !!(mode & AES_FLAGS_ENCRYPT);
 
        cryp = mtk_aes_find_dev(ctx);
        if (!cryp)
                return -ENODEV;
 
+       /* Compute text length. */
+       gctx->textlen = req->cryptlen - (enc ? 0 : gctx->authsize);
+
        /* Empty messages are not supported yet */
        if (!gctx->textlen && !req->assoclen)
                return -EINVAL;
 
        rctx->mode = AES_FLAGS_GCM | mode;
 
-       return mtk_aes_handle_queue(cryp, !!(mode & AES_FLAGS_ENCRYPT),
-                                   &req->base);
+       return mtk_aes_handle_queue(cryp, enc, &req->base);
 }
 
 /*
-- 
2.17.1