crypto: img-hash - Fix variable dereferenced before check 'hdev->req'

[ Upstream commit 04ba54e5af8f8f0137b08cb51a0b3a2e1ea46c94 ]

Smatch report warning as follows:

drivers/crypto/img-hash.c:366 img_hash_dma_task() warn: variable
dereferenced before check 'hdev->req'

Variable dereferenced should be done after check 'hdev->req',
fix it.

Fixes: d358f1abbf71 ("crypto: img-hash - Add Imagination Technologies hw hash accelerator")
Fixes: 10badea259fa ("crypto: img-hash - Fix null pointer exception")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/crypto/img-hash.c b/drivers/crypto/img-hash.c
index aa4c7b2..34b41cb 100644 (file)
--- a/drivers/crypto/img-hash.c
+++ b/drivers/crypto/img-hash.c
@@ -358,12 +358,16 @@ static int img_hash_dma_init(struct img_hash_dev *hdev)
 static void img_hash_dma_task(unsigned long d)
 {
        struct img_hash_dev *hdev = (struct img_hash_dev *)d;
-       struct img_hash_request_ctx *ctx = ahash_request_ctx(hdev->req);
+       struct img_hash_request_ctx *ctx;
        u8 *addr;
        size_t nbytes, bleft, wsend, len, tbc;
        struct scatterlist tsg;
 
-       if (!hdev->req || !ctx->sg)
+       if (!hdev->req)
+               return;
+
+       ctx = ahash_request_ctx(hdev->req);
+       if (!ctx->sg)
                return;
 
        addr = sg_virt(ctx->sg);