[PATCH] crypto: af_alg - use struct_size() in sock_kfree_s()

[PATCH] crypto: af_alg - use struct_size() in sock_kfree_s()

[Gustavo A. R. Silva]

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, change the following form:

sizeof(*sgl) + sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1)

to :

struct_size(sgl, sg, MAX_SGL_ENTS + 1)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 crypto/af_alg.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 65f4326d08f0..edca0998b2a4 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -637,8 +637,7 @@ void af_alg_pull_tsgl(struct sock *sk, size_t used, struct scatterlist *dst,
 		}
 
 		list_del(&sgl->list);
-		sock_kfree_s(sk, sgl, sizeof(*sgl) + sizeof(sgl->sg[0]) *
-						     (MAX_SGL_ENTS + 1));
+		sock_kfree_s(sk, sgl, struct_size(sgl, sg, MAX_SGL_ENTS + 1));
 	}
 
 	if (!ctx->used)
-- 
2.20.1

Re: [PATCH] crypto: af_alg - use struct_size() in sock_kfree_s()

[Herbert Xu]

On Thu, Feb 21, 2019 at 12:04:23PM -0600, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes, in particular in the
> context in which this code is being used.
> 
> So, change the following form:
> 
> sizeof(*sgl) + sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1)
> 
> to :
> 
> struct_size(sgl, sg, MAX_SGL_ENTS + 1)
> 
> This code was detected with the help of Coccinelle.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  crypto/af_alg.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt