drivers/crypto/ccp/sev-dev.c: get rid of pointless access_ok()

Contrary to the comments, those do *NOT* verify anything about
writability of memory, etc.

In all cases addresses are passed only to copy_to_user().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 896f190..7f97164 100644 (file)
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -371,8 +371,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
                goto cmd;
 
        /* allocate a physically contiguous buffer to store the CSR blob */
-       if (!access_ok(input.address, input.length) ||
-           input.length > SEV_FW_BLOB_MAX_SIZE) {
+       if (input.length > SEV_FW_BLOB_MAX_SIZE) {
                ret = -EFAULT;
                goto e_free;
        }
@@ -609,12 +608,6 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;
 
-       /* Check if we have write access to the userspace buffer */
-       if (input.address &&
-           input.length &&
-           !access_ok(input.address, input.length))
-               return -EFAULT;
-
        data = kzalloc(sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;
@@ -730,15 +723,13 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
                goto cmd;
 
        /* Allocate a physically contiguous buffer to store the PDH blob. */
-       if ((input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) ||
-           !access_ok(input.pdh_cert_address, input.pdh_cert_len)) {
+       if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) {
                ret = -EFAULT;
                goto e_free;
        }
 
        /* Allocate a physically contiguous buffer to store the cert chain blob. */
-       if ((input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) ||
-           !access_ok(input.cert_chain_address, input.cert_chain_len)) {
+       if (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) {
                ret = -EFAULT;
                goto e_free;
        }