2019-11-27 07:24:01

by Haiwei Li

Subject: [PATCH v2] KVM: SVM: Fix "error" isn't initialized

From e7f9c786e43ef4f890b8a01f15f8f00786f4b14a Mon Sep 17 00:00:00 2001
From: Haiwei Li <[email protected]>
Date: Wed, 27 Nov 2019 15:00:49 +0800
Subject: [PATCH v2] fix: 'error' is not initialized

There are a bunch of error paths were "error" isn't initialized.

Signed-off-by: Haiwei Li <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
---
arch/x86/kvm/svm.c | 3 ++-
drivers/crypto/ccp/psp-dev.c | 2 ++
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 362e874..9eef6fc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6308,7 +6308,8 @@ static int sev_flush_asids(void)
up_write(&sev_deactivate_lock);

if (ret)
- pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
+ pr_err("SEV: DF_FLUSH failed, ret=%d. PSP returned error=%#x\n",
+ ret, error);

return ret;
}
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 39fdd06..c486c24 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -155,6 +155,8 @@ static int __sev_do_cmd_locked(int cmd, void *data,
int *psp_ret)
unsigned int phys_lsb, phys_msb;
unsigned int reg, ret = 0;

+ *psp_ret = -1;
+
if (!psp)
return -ENODEV;

--
1.8.3.1

2019-11-27 08:47:45

by Miaohe Lin

Subject: Re: [PATCH v2] KVM: SVM: Fix "error" isn't initialized

> From e7f9c786e43ef4f890b8a01f15f8f00786f4b14a Mon Sep 17 00:00:00 2001
> From: Haiwei Li <[email protected]>
> Date: Wed, 27 Nov 2019 15:00:49 +0800
> Subject: [PATCH v2] fix: 'error' is not initialized
>
> There are a bunch of error paths were "error" isn't initialized.
> @@ -155,6 +155,8 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
> unsigned int phys_lsb, phys_msb;
> unsigned int reg, ret = 0;
>
> + *psp_ret = -1;
> +
> if (!psp)
> return -ENODEV;
>

The arg psp_ret may be NULL in some path such as sev_guest_df_flush(NULL).
So you have to check it against NULL.
Thanks.

2019-11-27 09:16:46

by Christophe de Dinechin

Subject: Re: [PATCH v2] KVM: SVM: Fix "error" isn't initialized

> On 27 Nov 2019, at 08:23, Haiwei Li <[email protected]> wrote:
>
> From e7f9c786e43ef4f890b8a01f15f8f00786f4b14a Mon Sep 17 00:00:00 2001
> From: Haiwei Li <[email protected]>
> Date: Wed, 27 Nov 2019 15:00:49 +0800
> Subject: [PATCH v2] fix: 'error' is not initialized
>
> There are a bunch of error paths were "error" isn't initialized.
>
> Signed-off-by: Haiwei Li <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
> ---
> arch/x86/kvm/svm.c | 3 ++-
> drivers/crypto/ccp/psp-dev.c | 2 ++
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 362e874..9eef6fc 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -6308,7 +6308,8 @@ static int sev_flush_asids(void)
> up_write(&sev_deactivate_lock);
>
> if (ret)
> - pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
> + pr_err("SEV: DF_FLUSH failed, ret=%d. PSP returned error=%#x\n",
> + ret, error);

This specific text change does not seem to match the patch description.

>
> return ret;
> }
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> index 39fdd06..c486c24 100644
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -155,6 +155,8 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
> unsigned int phys_lsb, phys_msb;
> unsigned int reg, ret = 0;
>
> + *psp_ret = -1;
> +
> if (!psp)
> return -ENODEV;
>
> --
> 1.8.3.1

2019-11-27 18:13:07

by Tom Lendacky

Subject: Re: [PATCH v2] KVM: SVM: Fix "error" isn't initialized

On 11/27/19 1:23 AM, Haiwei Li wrote:
> From e7f9c786e43ef4f890b8a01f15f8f00786f4b14a Mon Sep 17 00:00:00 2001
> From: Haiwei Li <[email protected]>
> Date: Wed, 27 Nov 2019 15:00:49 +0800
> Subject: [PATCH v2] fix: 'error' is not initialized
>
> There are a bunch of error paths were "error" isn't initialized.

Please provide a better patch commit message and just fix the actual
problem, which is error is uninitialized in sev_flush_asids(). Please
just initialize error to zero.

Thanks,
Tom

>
> Signed-off-by: Haiwei Li <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
> ---
>  arch/x86/kvm/svm.c           | 3 ++-
>  drivers/crypto/ccp/psp-dev.c | 2 ++
>  2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 362e874..9eef6fc 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -6308,7 +6308,8 @@ static int sev_flush_asids(void)
>      up_write(&sev_deactivate_lock);
>
>      if (ret)
> -        pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
> +        pr_err("SEV: DF_FLUSH failed, ret=%d. PSP returned error=%#x\n",
> +               ret, error);
>
>      return ret;
>  }
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> index 39fdd06..c486c24 100644
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -155,6 +155,8 @@ static int __sev_do_cmd_locked(int cmd, void *data,
> int *psp_ret)
>      unsigned int phys_lsb, phys_msb;
>      unsigned int reg, ret = 0;
>
> +    *psp_ret = -1;
> +
>      if (!psp)
>          return -ENODEV;
>
> --
> 1.8.3.1