2021-08-16 19:25:16

by Tom Rix

Subject: [PATCH] crypto: initialize error variable

From: Tom Rix <[email protected]>

Static analysis reports this problem
sev-dev.c:1094:19: warning: The left operand of '==' is a garbage value
if (rc && (error == SEV_RET_SECURE_DATA_INVALID)) {
~~~~~ ^

The error variable may not be set by the call to
sev_platform_init(). So initialize error to SEV_RET_SUCCESS.

Fixes: 1d55fdc85799 ("crypto: ccp - Retry SEV INIT command in case of integrity check failure.")
Signed-off-by: Tom Rix <[email protected]>
---
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 2ecb0e1f65d8d..b2b9f0f4daf2d 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1065,7 +1065,7 @@ void sev_pci_init(void)
{
struct sev_device *sev = psp_master->sev_data;
struct page *tmr_page;
- int error, rc;
+ int error = SEV_RET_SUCCESS, rc;

if (!sev)
return;
--
2.26.3

2021-08-16 20:02:52

by Tom Lendacky

Subject: Re: [PATCH] crypto: initialize error variable

On 8/16/21 2:23 PM, [email protected] wrote:
> From: Tom Rix <[email protected]>
>
> Static analysis reports this problem
> sev-dev.c:1094:19: warning: The left operand of '==' is a garbage value
> if (rc && (error == SEV_RET_SECURE_DATA_INVALID)) {
> ~~~~~ ^
>
> The error variable may not be set by the call to
> sev_platform_init(). So initialize error to SEV_RET_SUCCESS.
>
> Fixes: 1d55fdc85799 ("crypto: ccp - Retry SEV INIT command in case of integrity check failure.")
> Signed-off-by: Tom Rix <[email protected]>
> ---
> 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 2ecb0e1f65d8d..b2b9f0f4daf2d 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1065,7 +1065,7 @@ void sev_pci_init(void)
> {
> struct sev_device *sev = psp_master->sev_data;
> struct page *tmr_page;
> - int error, rc;
> + int error = SEV_RET_SUCCESS, rc;

Looking ahead to recently submitted SEV-SNP patches that will also use the
error variable (and will also need to initialize it), lets move the
initialization of error to just before the call to sev_platform_init() so
it doesn't end up with a possible stale value in the future:

https://lore.kernel.org/lkml/[email protected]/

Thanks,
Tom

>
> if (!sev)
> return;
>