1 files changed, 134 insertions, 9 deletions

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 31a0fd8189f1..427fddcaeb19 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -913,6 +913,21 @@ static int keyctl_change_reqkey_auth(struct key *key)
 }
 
 /*
+ * 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 @@ static int keyctl_change_reqkey_auth(struct key *key)
  *
  * 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 @@ long keyctl_instantiate_key(key_serial_t id,
         /* 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 @@ long keyctl_instantiate_key(key_serial_t id,
                                 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 @@ error:
 }
 
 /*
+ * 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.
  *
@@ -1013,12 +1095,42 @@ error:
  */
 long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
 {
+        return keyctl_reject_key(id, timeout, ENOKEY, ringid);
+}
+
+/*
+ * Negatively instantiate the key with the given timeout (in seconds) and error
+ * code 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.
+ *
+ * The key and any links to the key will be automatically garbage collected
+ * after the timeout expires.
+ *
+ * Negative keys are used to rate limit repeated request_key() calls by causing
+ * them to return the specified error code until the negative key expires.
+ *
+ * If successful, 0 will be returned.
+ */
+long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error,
+                       key_serial_t ringid)
+{
         const struct cred *cred = current_cred();
         struct request_key_auth *rka;
         struct key *instkey, *dest_keyring;
         long ret;
 
-        kenter("%d,%u,%d", id, timeout, ringid);
+        kenter("%d,%u,%u,%d", id, timeout, error, ringid);
+
+        /* must be a valid error code and mustn't be a kernel special */
+        if (error <= 0 ||
+            error >= MAX_ERRNO ||
+            error == ERESTARTSYS ||
+            error == ERESTARTNOINTR ||
+            error == ERESTARTNOHAND ||
+            error == ERESTART_RESTARTBLOCK)
+                return -EINVAL;
 
         /* the appropriate instantiation authorisation key must have been
          * assumed before calling this */
@@ -1038,7 +1150,7 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
                 goto error;
 
         /* instantiate the key and link it into a keyring */
-        ret = key_negate_and_link(rka->target_key, timeout,
+        ret = key_reject_and_link(rka->target_key, timeout, error,
                                   dest_keyring, instkey);
 
         key_put(dest_keyring);
@@ -1492,6 +1604,19 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
         case KEYCTL_SESSION_TO_PARENT:
                 return keyctl_session_to_parent();
 
+        case KEYCTL_REJECT:
+                return keyctl_reject_key((key_serial_t) arg2,
+                                         (unsigned) arg3,
+                                         (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;
         }