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authorDan Williams <dan.j.williams@intel.com>2023-07-18 17:55:50 -0700
committerDan Williams <dan.j.williams@intel.com>2023-10-19 18:11:38 -0700
commit2df2135366833c372f3a14ffcc655f9c5724d972 (patch)
tree00f402547c375882bfc46bb1154478aab79bcd60 /drivers
parent70e6f7e2b98575621019aa40ac616be58ff984e0 (diff)
virt: sevguest: Prep for kernel internal get_ext_report()
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> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/virt/coco/sev-guest/sev-guest.c44
1 files 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 @@ cmd:
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;