[PATCH v6] cypto: mediatek - fix leaks in mtk_desc_ring_alloc

[Xiaoliang Pang]

In the init loop, if an error occurs in function 'dma_alloc_coherent',
then goto the err_cleanup section, after run i--,
in the array ring, the struct mtk_ring with index i will not be released,
causing memory leaks

Fixes: 785e5c616c849 ("crypto: mediatek - Add crypto driver support for some 
MediaTek chips")
Cc: Ryder Lee <ryder....@mediatek.com>
Signed-off-by: Xiaoliang Pang <dawning.p...@gmail.com>
---
 drivers/crypto/mediatek/mtk-platform.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/mediatek/mtk-platform.c 
b/drivers/crypto/mediatek/mtk-platform.c
index 7e3ad085b5bd..f83cead30d8f 100644
--- a/drivers/crypto/mediatek/mtk-platform.c
+++ b/drivers/crypto/mediatek/mtk-platform.c
@@ -469,13 +469,13 @@ static int mtk_desc_ring_alloc(struct mtk_cryp *cryp)
        return 0;
 
 err_cleanup:
-       for (; i--; ) {
+       do {
                dma_free_coherent(cryp->dev, MTK_DESC_RING_SZ,
                                  ring[i]->res_base, ring[i]->res_dma);
                dma_free_coherent(cryp->dev, MTK_DESC_RING_SZ,
                                  ring[i]->cmd_base, ring[i]->cmd_dma);
                kfree(ring[i]);
-       }
+       } while (i--);
        return err;
 }
 
-- 
2.17.1