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SubjectRe: [Part2 PATCH v5.1 12.7/31] crypto: ccp: Implement SEV_PEK_CSR ioctl command
On Thu, Oct 12, 2017 at 09:24:01PM -0500, Brijesh Singh wrote:
> I assume you mean performing the SEV state check before allocating the
> memory for the CSR blob, right ?

I mean, do those first:

if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
return -EFAULT;

if (!input.address)
return -EINVAL;

/* allocate a physically contiguous buffer to store the CSR blob */
if (!access_ok(VERIFY_WRITE, input.address, input.length) ||
input.length > SEV_FW_BLOB_MAX_SIZE)
return -EFAULT;


Because if you allocate the memory first and some of those checks fail,
you allocate in vain to free it immediately after. And you can save
yourself all that.

--
Regards/Gruss,
Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
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