Commit dda03e2c authored by Reinette Chatre's avatar Reinette Chatre Committed by Dave Hansen
Browse files

x86/sgx: Create utility to validate user provided offset and length 



User provided offset and length is validated when parsing the parameters
of the SGX_IOC_ENCLAVE_ADD_PAGES ioctl(). Extract this validation
(with consistent use of IS_ALIGNED) into a utility that can be used
by the SGX2 ioctl()s that will also provide these values.

Signed-off-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/767147bc100047abed47fe27c592901adfbb93a2.1652137848.git.reinette.chatre@intel.com
parent c7c6a8a6

arch/x86/kernel/cpu/sgx/ioctl.c

+22 −6
Original line number Diff line number Diff line
@@ -372,6 +372,26 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, 
	return ret;

}



/*

 * Ensure user provided offset and length values are valid for

 * an enclave.

 */

static int sgx_validate_offset_length(struct sgx_encl *encl,

				      unsigned long offset,

				      unsigned long length)

{

	if (!IS_ALIGNED(offset, PAGE_SIZE))

		return -EINVAL;



	if (!length || !IS_ALIGNED(length, PAGE_SIZE))

		return -EINVAL;



	if (offset + length - PAGE_SIZE >= encl->size)

		return -EINVAL;



	return 0;

}



/**

 * sgx_ioc_enclave_add_pages() - The handler for %SGX_IOC_ENCLAVE_ADD_PAGES

 * @encl:       an enclave pointer
@@ -425,14 +445,10 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) 
	if (copy_from_user(&add_arg, arg, sizeof(add_arg)))

		return -EFAULT;



	if (!IS_ALIGNED(add_arg.offset, PAGE_SIZE) ||

	    !IS_ALIGNED(add_arg.src, PAGE_SIZE))

		return -EINVAL;



	if (!add_arg.length || add_arg.length & (PAGE_SIZE - 1))

	if (!IS_ALIGNED(add_arg.src, PAGE_SIZE))

		return -EINVAL;



	if (add_arg.offset + add_arg.length - PAGE_SIZE >= encl->size)

	if (sgx_validate_offset_length(encl, add_arg.offset, add_arg.length))

		return -EINVAL;



	if (copy_from_user(&secinfo, (void __user *)add_arg.secinfo,