crypto: inside-secure/eip93 - Correctly handle return of for sg_nents_for_len

Fix smatch warning for sg_nents_for_len return value in Inside Secure
EIP93 driver.

The return value of sg_nents_for_len was assigned to an u32 and the
error was ignored and converted to a positive integer.

Rework the code to correctly handle the error from sg_nents_for_len to
mute smatch warning.

Fixes: 9739f5f93b78 ("crypto: eip93 - Add Inside Secure SafeXcel EIP-93 crypto engine support")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/inside-secure/eip93/eip93-common.c b/drivers/crypto/inside-secure/eip93/eip93-common.c
index 446a047c242d6b1bfeafbf3b99f2a780b0d8c04f..66153aa2493f259f1452cf894e0a329240dd8998 100644 (file)
--- a/drivers/crypto/inside-secure/eip93/eip93-common.c
+++ b/drivers/crypto/inside-secure/eip93/eip93-common.c
@@ -202,7 +202,6 @@ int check_valid_request(struct eip93_cipher_reqctx *rctx)
 {
        struct scatterlist *src = rctx->sg_src;
        struct scatterlist *dst = rctx->sg_dst;
-       u32 src_nents, dst_nents;
        u32 textsize = rctx->textsize;
        u32 authsize = rctx->authsize;
        u32 blksize = rctx->blksize;
@@ -210,6 +209,7 @@ int check_valid_request(struct eip93_cipher_reqctx *rctx)
        u32 totlen_dst = rctx->assoclen + rctx->textsize;
        u32 copy_len;
        bool src_align, dst_align;
+       int src_nents, dst_nents;
        int err = -EINVAL;
 
        if (!IS_CTR(rctx->flags)) {
@@ -225,19 +225,24 @@ int check_valid_request(struct eip93_cipher_reqctx *rctx)
        }
 
        src_nents = sg_nents_for_len(src, totlen_src);
+       if (src_nents < 0)
+               return src_nents;
+
        dst_nents = sg_nents_for_len(dst, totlen_dst);
+       if (dst_nents < 0)
+               return dst_nents;
 
        if (src == dst) {
                src_nents = max(src_nents, dst_nents);
                dst_nents = src_nents;
-               if (unlikely((totlen_src || totlen_dst) && src_nents <= 0))
+               if (unlikely((totlen_src || totlen_dst) && !src_nents))
                        return err;
 
        } else {
-               if (unlikely(totlen_src && src_nents <= 0))
+               if (unlikely(totlen_src && !src_nents))
                        return err;
 
-               if (unlikely(totlen_dst && dst_nents <= 0))
+               if (unlikely(totlen_dst && !dst_nents))
                        return err;
        }
 
@@ -273,8 +278,16 @@ int check_valid_request(struct eip93_cipher_reqctx *rctx)
                        return err;
        }
 
-       rctx->src_nents = sg_nents_for_len(rctx->sg_src, totlen_src);
-       rctx->dst_nents = sg_nents_for_len(rctx->sg_dst, totlen_dst);
+       src_nents = sg_nents_for_len(rctx->sg_src, totlen_src);
+       if (src_nents < 0)
+               return src_nents;
+
+       dst_nents = sg_nents_for_len(rctx->sg_dst, totlen_dst);
+       if (dst_nents < 0)
+               return dst_nents;
+
+       rctx->src_nents = src_nents;
+       rctx->dst_nents = dst_nents;
 
        return 0;
 }