From: Dan Williams <dan.j.williams@intel.com>
To: linux-coco@lists.linux.dev
Cc: Borislav Petkov <bp@alien8.de>,
Tom Lendacky <thomas.lendacky@amd.com>,
Dionna Glaze <dionnaglaze@google.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
peterz@infradead.org, sathyanarayanan.kuppuswamy@linux.intel.com,
dave.hansen@linux.intel.com, bp@alien8.de
Subject: [PATCH v5 4/7] virt: sevguest: Prep for kernel internal get_ext_report()
Date: Tue, 10 Oct 2023 22:27:35 -0700 [thread overview]
Message-ID: <169700205493.779347.10439367445430173053.stgit@dwillia2-xfh.jf.intel.com> (raw)
In-Reply-To: <169700203032.779347.11603484721811916604.stgit@dwillia2-xfh.jf.intel.com>
In preparation for using the configs-tsm facility to convey attestation
blobs to userspace, switch to using the 'sockptr' api for copying
payloads to provided buffers where 'sockptr' handles user vs kernel
buffers.
While configfs-tsm is meant to replace existing confidential computing
ioctl() implementations for attestation report retrieval the old ioctl()
path needs to stick around for a deprecation period.
No behavior change intended.
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Dionna Glaze <dionnaglaze@google.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/virt/coco/sev-guest/sev-guest.c | 44 +++++++++++++++++++++++--------
1 file changed, 32 insertions(+), 12 deletions(-)
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index 5bee58ef5f1e..e5f8f115f4af 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -19,6 +19,7 @@
#include <crypto/aead.h>
#include <linux/scatterlist.h>
#include <linux/psp-sev.h>
+#include <linux/sockptr.h>
#include <uapi/linux/sev-guest.h>
#include <uapi/linux/psp-sev.h>
@@ -475,6 +476,11 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
return 0;
}
+struct snp_req_resp {
+ sockptr_t req_data;
+ sockptr_t resp_data;
+};
+
static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
{
struct snp_guest_crypto *crypto = snp_dev->crypto;
@@ -555,22 +561,25 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
return rc;
}
-static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
+static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg,
+ struct snp_req_resp *io)
+
{
struct snp_ext_report_req *req = &snp_dev->req.ext_report;
struct snp_guest_crypto *crypto = snp_dev->crypto;
struct snp_report_resp *resp;
int ret, npages = 0, resp_len;
+ sockptr_t certs_address;
lockdep_assert_held(&snp_cmd_mutex);
- if (!arg->req_data || !arg->resp_data)
+ if (sockptr_is_null(io->req_data) || sockptr_is_null(io->resp_data))
return -EINVAL;
- if (copy_from_user(req, (void __user *)arg->req_data, sizeof(*req)))
+ if (copy_from_sockptr(req, io->req_data, sizeof(*req)))
return -EFAULT;
- /* userspace does not want certificate data */
+ /* caller does not want certificate data */
if (!req->certs_len || !req->certs_address)
goto cmd;
@@ -578,8 +587,13 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
!IS_ALIGNED(req->certs_len, PAGE_SIZE))
return -EINVAL;
- if (!access_ok((const void __user *)req->certs_address, req->certs_len))
- return -EFAULT;
+ if (sockptr_is_kernel(io->resp_data)) {
+ certs_address = KERNEL_SOCKPTR((void *)req->certs_address);
+ } else {
+ certs_address = USER_SOCKPTR((void __user *)req->certs_address);
+ if (!access_ok(certs_address.user, req->certs_len))
+ return -EFAULT;
+ }
/*
* Initialize the intermediate buffer with all zeros. This buffer
@@ -609,21 +623,19 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
if (arg->vmm_error == SNP_GUEST_VMM_ERR_INVALID_LEN) {
req->certs_len = snp_dev->input.data_npages << PAGE_SHIFT;
- if (copy_to_user((void __user *)arg->req_data, req, sizeof(*req)))
+ if (copy_to_sockptr(io->req_data, req, sizeof(*req)))
ret = -EFAULT;
}
if (ret)
goto e_free;
- if (npages &&
- copy_to_user((void __user *)req->certs_address, snp_dev->certs_data,
- req->certs_len)) {
+ if (npages && copy_to_sockptr(certs_address, snp_dev->certs_data, req->certs_len)) {
ret = -EFAULT;
goto e_free;
}
- if (copy_to_user((void __user *)arg->resp_data, resp, sizeof(*resp)))
+ if (copy_to_sockptr(io->resp_data, resp, sizeof(*resp)))
ret = -EFAULT;
e_free:
@@ -636,6 +648,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
struct snp_guest_dev *snp_dev = to_snp_dev(file);
void __user *argp = (void __user *)arg;
struct snp_guest_request_ioctl input;
+ struct snp_req_resp io;
int ret = -ENOTTY;
if (copy_from_user(&input, argp, sizeof(input)))
@@ -664,7 +677,14 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
ret = get_derived_key(snp_dev, &input);
break;
case SNP_GET_EXT_REPORT:
- ret = get_ext_report(snp_dev, &input);
+ /*
+ * As get_ext_report() may be called from the ioctl() path and a
+ * kernel internal path (configfs-tsm), decorate the passed
+ * buffers as user pointers.
+ */
+ io.req_data = USER_SOCKPTR((void __user *)input.req_data);
+ io.resp_data = USER_SOCKPTR((void __user *)input.resp_data);
+ ret = get_ext_report(snp_dev, &input, &io);
break;
default:
break;
next prev parent reply other threads:[~2023-10-11 5:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-11 5:27 [PATCH v5 0/7] configfs-tsm: Attestation Report ABI Dan Williams
2023-10-11 5:27 ` [PATCH v5 1/7] virt: sevguest: Fix passing a stack buffer as a scatterlist target Dan Williams
2023-10-11 5:27 ` [PATCH v5 2/7] virt: coco: Add a coco/Makefile and coco/Kconfig Dan Williams
2023-10-11 5:27 ` [PATCH v5 3/7] configfs-tsm: Introduce a shared ABI for attestation reports Dan Williams
2023-10-11 6:29 ` Kuppuswamy Sathyanarayanan
2023-10-11 5:27 ` Dan Williams [this message]
2023-10-11 5:27 ` [PATCH v5 5/7] mm/slab: Add __free() support for kvfree Dan Williams
2023-10-11 6:31 ` Kuppuswamy Sathyanarayanan
2023-10-11 5:27 ` [PATCH v5 6/7] virt: sevguest: Add TSM_REPORTS support for SNP_GET_EXT_REPORT Dan Williams
2023-10-11 16:13 ` Dionna Amalie Glaze
2023-10-11 20:41 ` Dan Williams
2023-10-11 21:06 ` Dionna Amalie Glaze
2023-10-11 19:24 ` Tom Lendacky
2023-10-11 21:30 ` Dan Williams
2023-10-11 22:21 ` Dionna Amalie Glaze
2023-10-11 22:24 ` Tom Lendacky
2023-10-12 0:38 ` Dan Williams
2023-10-11 5:27 ` [PATCH v5 7/7] virt: tdx-guest: Add Quote generation support using TSM_REPORTS Dan Williams
2023-10-11 6:44 ` [PATCH v5 0/7] configfs-tsm: Attestation Report ABI Kuppuswamy Sathyanarayanan
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