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Message-ID: <6f11a61f-1575-2886-0198-1f5947f9f835@linux.alibaba.com>
Date:   Fri, 15 Sep 2023 19:18:42 +0800
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Subject: Re: [bug report] lib/mpi: Extend the MPI library
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To:     Dan Carpenter <dan.carpenter@linaro.org>
Cc:     linux-crypto@vger.kernel.org
References: <800d9813-af24-4b4a-ba0f-45a37515902c@moroto.mountain>
From:   Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
In-Reply-To: <800d9813-af24-4b4a-ba0f-45a37515902c@moroto.mountain>
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Hi, Dan Carpenter,

On 9/15/23 3:21 PM, Dan Carpenter wrote:
> Hello Tianjia Zhang,
> 
> The patch a8ea8bdd9df9: "lib/mpi: Extend the MPI library" from Sep
> 21, 2020 (linux-next), leads to the following Smatch static checker
> warning:
> 
> lib/crypto/mpi/mpiutil.c:202 mpi_copy() error: potential null dereference 'b'.  (mpi_alloc returns null)
> lib/crypto/mpi/mpiutil.c:224 mpi_alloc_like() error: potential null dereference 'b'.  (mpi_alloc returns null)
> lib/crypto/mpi/mpiutil.c:258 mpi_set() error: potential null dereference 'w'.  (<unknown> returns null)
> lib/crypto/mpi/mpiutil.c:277 mpi_set_ui() error: potential null dereference 'w'.  (<unknown> returns null)
> lib/crypto/mpi/mpiutil.c:289 mpi_alloc_set_ui() error: potential null dereference 'w'.  (mpi_alloc returns null)
> 
> lib/crypto/mpi/mpiutil.c
>      195 MPI mpi_copy(MPI a)
>      196 {
>      197         int i;
>      198         MPI b;
>      199
>      200         if (a) {
>      201                 b = mpi_alloc(a->nlimbs);
> 
> Allocations can fail.
> 
> --> 202                 b->nlimbs = a->nlimbs;
>      203                 b->sign = a->sign;
>      204                 b->flags = a->flags;
>      205                 b->flags &= ~(16|32); /* Reset the immutable and constant flags. */
>      206                 for (i = 0; i < b->nlimbs; i++)
>      207                         b->d[i] = a->d[i];
>      208         } else
>      209                 b = NULL;
>      210         return b;
>      211 }
> 
> regards,
> dan carpenter

Thanks for reminding me, these are some remaining issues that needs more
modifications. I will take the time to fix them.

Cheers,
Tianjia