The "err" variable may be returned without an initialized value.

Fixes: 8e3a67f2de87 ("crypto: lib/mpi - Add error checks to extension")
Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
---
 lib/crypto/mpi/mpi-mul.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/crypto/mpi/mpi-mul.c b/lib/crypto/mpi/mpi-mul.c
index 892a246216b9..7e6ff1ce3e9b 100644
--- a/lib/crypto/mpi/mpi-mul.c
+++ b/lib/crypto/mpi/mpi-mul.c
@@ -21,7 +21,7 @@ int mpi_mul(MPI w, MPI u, MPI v)
 	int usign, vsign, sign_product;
 	int assign_wp = 0;
 	mpi_ptr_t tmp_limb = NULL;
-	int err;
+	int err = 0;
 
 	if (u->nlimbs < v->nlimbs) {
 		/* Swap U and V. */
-- 
2.34.1

On Fri, Sep 13, 2024 at 10:07:42PM +0800, Qianqiang Liu wrote:
> The "err" variable may be returned without an initialized value.
> 
> Fixes: 8e3a67f2de87 ("crypto: lib/mpi - Add error checks to extension")
> Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
> ---
>  lib/crypto/mpi/mpi-mul.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/crypto/mpi/mpi-mul.c b/lib/crypto/mpi/mpi-mul.c
> index 892a246216b9..7e6ff1ce3e9b 100644
> --- a/lib/crypto/mpi/mpi-mul.c
> +++ b/lib/crypto/mpi/mpi-mul.c
> @@ -21,7 +21,7 @@ int mpi_mul(MPI w, MPI u, MPI v)
>  	int usign, vsign, sign_product;
>  	int assign_wp = 0;
>  	mpi_ptr_t tmp_limb = NULL;
> -	int err;
> +	int err = 0;
>  
>  	if (u->nlimbs < v->nlimbs) {
>  		/* Swap U and V. */
> -- 
> 2.34.1

Could you please review this patch?

-- 
Best,
Qianqiang Liu

On Sat, Sep 14, 2024 at 08:53:30AM +0800, Qianqiang Liu wrote:
> On Fri, Sep 13, 2024 at 10:07:42PM +0800, Qianqiang Liu wrote:
> > The "err" variable may be returned without an initialized value.
> > 
> > Fixes: 8e3a67f2de87 ("crypto: lib/mpi - Add error checks to extension")
> > Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
> > ---
> >  lib/crypto/mpi/mpi-mul.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/lib/crypto/mpi/mpi-mul.c b/lib/crypto/mpi/mpi-mul.c
> > index 892a246216b9..7e6ff1ce3e9b 100644
> > --- a/lib/crypto/mpi/mpi-mul.c
> > +++ b/lib/crypto/mpi/mpi-mul.c
> > @@ -21,7 +21,7 @@ int mpi_mul(MPI w, MPI u, MPI v)
> >  	int usign, vsign, sign_product;
> >  	int assign_wp = 0;
> >  	mpi_ptr_t tmp_limb = NULL;
> > -	int err;
> > +	int err = 0;
> >  
> >  	if (u->nlimbs < v->nlimbs) {
> >  		/* Swap U and V. */
> > -- 
> > 2.34.1
> 
> Could you please review this patch?

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

Qianqiang Liu <qianqiang.liu@163.com> writes:

> On Fri, Sep 13, 2024 at 10:07:42PM +0800, Qianqiang Liu wrote:
>> The "err" variable may be returned without an initialized value.
>> 
>> Fixes: 8e3a67f2de87 ("crypto: lib/mpi - Add error checks to extension")
>> Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
Thanks for the patch.

You can update the commit message and subject line to be more specific.

***
example
Subject: crypto: lib/mpi - Fix return of uninitailized variable err

If no error occurs, "err" variable will be returned with uninitialized
value, which is actually a success case scenario and return value should
have been zero.
***

This makes the need of entire fix more clear.
I think currently no body is checking return value of this function as
this is recent introduction or this would have failed.

Kamlesh

Kamlesh Gurudasani <kamlesh@ti.com> writes:

> Qianqiang Liu <qianqiang.liu@163.com> writes:
>
>> On Fri, Sep 13, 2024 at 10:07:42PM +0800, Qianqiang Liu wrote:
>>> The "err" variable may be returned without an initialized value.
>>> 
>>> Fixes: 8e3a67f2de87 ("crypto: lib/mpi - Add error checks to extension")
>>> Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
> Thanks for the patch.
>
> You can update the commit message and subject line to be more specific.
>
> ***
> example
> Subject: crypto: lib/mpi - Fix return of uninitailized variable err
>
> If no error occurs, "err" variable will be returned with uninitialized
> value, which is actually a success case scenario and return value should
> have been zero.
My bad when I looked in detail,

   	if (!vsize)
		wsize = 0;
if this condition is true, mpihelp_mul will never be called, leaving err
uninitialized, not sure if that is success case scenario or failure.

If that is success case scenario, this fix will do the work, if it is
failure case scenario, appropriate return value should also needed to be 
err.

In any case, the commit message that I have mentioned will not be
correct, so please scratch that.

Kamlesh