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From:   Peter Gonda <pgonda@google.com>
Date:   Tue, 10 Jan 2023 09:27:34 -0700
Message-ID: <CAMkAt6oqBH35=moST5nO_BXwc8k0M4h_8TvT9H6outR9vOw5qg@mail.gmail.com>
Subject: Re: [PATCH] crypto: initialize error
To:     Tom Rix <trix@redhat.com>
Cc:     brijesh.singh@amd.com, thomas.lendacky@amd.com, john.allen@amd.com,
        herbert@gondor.apana.org.au, davem@davemloft.net,
        nathan@kernel.org, ndesaulniers@google.com, rientjes@google.com,
        marcorr@google.com, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev
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On Tue, Jan 10, 2023 at 9:18 AM Tom Rix <trix@redhat.com> wrote:
>
> clang static analysis reports this problem
> drivers/crypto/ccp/sev-dev.c:1347:3: warning: 3rd function call
>   argument is an uninitialized value [core.CallAndMessage]
>     dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
>     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> __sev_platform_init_locked() can return without setting the
> error parameter, causing the dev_err() to report a gargage

garbage

> value.
>
> Fixes: 3d725965f836 ("crypto: ccp - Add SEV_INIT_EX support")

Should this be: 'Fixes: 200664d5237f ("crypto: ccp: Add Secure
Encrypted Virtualization (SEV) command support")'

Since in that patch an uninitialized error can be printed?

+void psp_pci_init(void)
+{
+       struct sev_user_data_status *status;
+       struct sp_device *sp;
+       int error, rc;
+
+       sp = sp_get_psp_master_device();
+       if (!sp)
+               return;
+
+       psp_master = sp->psp_data;
+
+       /* Initialize the platform */
+       rc = sev_platform_init(&error);
+       if (rc) {
+               dev_err(sp->dev, "SEV: failed to INIT error %#x\n", error);
+               goto err;
+       }


...

+static int __sev_platform_init_locked(int *error)
+{
+       struct psp_device *psp = psp_master;
+       int rc = 0;
+
+       if (!psp)
+               return -ENODEV;
+
+       if (psp->sev_state == SEV_STATE_INIT)
+               return 0;


So if !psp an uninitialized error is printed?

> Signed-off-by: Tom Rix <trix@redhat.com>
> ---
>  drivers/crypto/ccp/sev-dev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index 56998bc579d6..643cccc06a0b 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1307,7 +1307,7 @@ EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
>  void sev_pci_init(void)
>  {
>         struct sev_device *sev = psp_master->sev_data;
> -       int error, rc;
> +       int error = 0, rc;
>
>         if (!sev)
>                 return;
> --
> 2.27.0
>