KEYS: Add an iovec version of KEYCTL_INSTANTIATE
Add a keyctl op (KEYCTL_INSTANTIATE_IOV) that is like KEYCTL_INSTANTIATE, but
takes an iovec array and concatenates the data in-kernel into one buffer.
Since the KEYCTL_INSTANTIATE copies the data anyway, this isn't too much of a
problem.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 0d7b194..427fddc 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -913,6 +913,21 @@
}
/*
+ * Copy the iovec data from userspace
+ */
+static long copy_from_user_iovec(void *buffer, const struct iovec *iov,
+ unsigned ioc)
+{
+ for (; ioc > 0; ioc--) {
+ if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0)
+ return -EFAULT;
+ buffer += iov->iov_len;
+ iov++;
+ }
+ return 0;
+}
+
+/*
* Instantiate a key with the specified payload and link the key into the
* destination keyring if one is given.
*
@@ -921,10 +936,11 @@
*
* If successful, 0 will be returned.
*/
-long keyctl_instantiate_key(key_serial_t id,
- const void __user *_payload,
- size_t plen,
- key_serial_t ringid)
+long keyctl_instantiate_key_common(key_serial_t id,
+ const struct iovec *payload_iov,
+ unsigned ioc,
+ size_t plen,
+ key_serial_t ringid)
{
const struct cred *cred = current_cred();
struct request_key_auth *rka;
@@ -953,7 +969,7 @@
/* pull the payload in if one was supplied */
payload = NULL;
- if (_payload) {
+ if (payload_iov) {
ret = -ENOMEM;
payload = kmalloc(plen, GFP_KERNEL);
if (!payload) {
@@ -965,8 +981,8 @@
goto error;
}
- ret = -EFAULT;
- if (copy_from_user(payload, _payload, plen) != 0)
+ ret = copy_from_user_iovec(payload, payload_iov, ioc);
+ if (ret < 0)
goto error2;
}
@@ -997,6 +1013,72 @@
}
/*
+ * Instantiate a key with the specified payload and link the key into the
+ * destination keyring if one is given.
+ *
+ * The caller must have the appropriate instantiation permit set for this to
+ * work (see keyctl_assume_authority). No other permissions are required.
+ *
+ * If successful, 0 will be returned.
+ */
+long keyctl_instantiate_key(key_serial_t id,
+ const void __user *_payload,
+ size_t plen,
+ key_serial_t ringid)
+{
+ if (_payload && plen) {
+ struct iovec iov[1] = {
+ [0].iov_base = (void __user *)_payload,
+ [0].iov_len = plen
+ };
+
+ return keyctl_instantiate_key_common(id, iov, 1, plen, ringid);
+ }
+
+ return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
+}
+
+/*
+ * Instantiate a key with the specified multipart payload and link the key into
+ * the destination keyring if one is given.
+ *
+ * The caller must have the appropriate instantiation permit set for this to
+ * work (see keyctl_assume_authority). No other permissions are required.
+ *
+ * If successful, 0 will be returned.
+ */
+long keyctl_instantiate_key_iov(key_serial_t id,
+ const struct iovec __user *_payload_iov,
+ unsigned ioc,
+ key_serial_t ringid)
+{
+ struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+ long ret;
+
+ if (_payload_iov == 0 || ioc == 0)
+ goto no_payload;
+
+ ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
+ ARRAY_SIZE(iovstack), iovstack, &iov);
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ goto no_payload_free;
+
+ ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
+
+ if (iov != iovstack)
+ kfree(iov);
+ return ret;
+
+no_payload_free:
+ if (iov != iovstack)
+ kfree(iov);
+no_payload:
+ return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
+}
+
+/*
* Negatively instantiate the key with the given timeout (in seconds) and link
* the key into the destination keyring if one is given.
*
@@ -1528,6 +1610,13 @@
(unsigned) arg4,
(key_serial_t) arg5);
+ case KEYCTL_INSTANTIATE_IOV:
+ return keyctl_instantiate_key_iov(
+ (key_serial_t) arg2,
+ (const struct iovec __user *) arg3,
+ (unsigned) arg4,
+ (key_serial_t) arg5);
+
default:
return -EOPNOTSUPP;
}