switch keyctl_instantiate_key_common() to iov_iter

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

3 files changed, 40 insertions, 72 deletions

diff --git a/security/keys/compat.c b/security/keys/compat.c
index 347896548ad3..25430a3aa7f7 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -31,30 +31,21 @@ static long compat_keyctl_instantiate_key_iov(
         key_serial_t ringid)
 {
         struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+        struct iov_iter from;
         long ret;
 
-        if (!_payload_iov || !ioc)
-                goto no_payload;
+        if (!_payload_iov)
+                ioc = 0;
 
-        ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc,
-                                           ARRAY_SIZE(iovstack),
-                                           iovstack, &iov);
+        ret = compat_import_iovec(WRITE, _payload_iov, ioc,
+                                  ARRAY_SIZE(iovstack), &iov,
+                                  &from);
         if (ret < 0)
-                goto err;
-        if (ret == 0)
-                goto no_payload_free;
-
-        ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
-err:
-        if (iov != iovstack)
-                kfree(iov);
-        return ret;
+                return ret;
 
-no_payload_free:
-        if (iov != iovstack)
-                kfree(iov);
-no_payload:
-        return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
+        ret = keyctl_instantiate_key_common(id, &from, ringid);
+        kfree(iov);
+        return ret;
 }
 
 /*
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 200e37867336..5105c2c2da75 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -243,9 +243,10 @@ extern long keyctl_instantiate_key_iov(key_serial_t,
                                        unsigned, key_serial_t);
 extern long keyctl_invalidate_key(key_serial_t);
 
+struct iov_iter;
 extern long keyctl_instantiate_key_common(key_serial_t,
-                                          const struct iovec *,
-                                          unsigned, size_t, key_serial_t);
+                                          struct iov_iter *,
+                                          key_serial_t);
 #ifdef CONFIG_PERSISTENT_KEYRINGS
 extern long keyctl_get_persistent(uid_t, key_serial_t);
 extern unsigned persistent_keyring_expiry;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 4743d71e4aa6..0b9ec78a7a7a 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -998,21 +998,6 @@ 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.
  *
@@ -1022,20 +1007,21 @@ static long copy_from_user_iovec(void *buffer, const struct iovec *iov,
  * If successful, 0 will be returned.
  */
 long keyctl_instantiate_key_common(key_serial_t id,
-                                   const struct iovec *payload_iov,
-                                   unsigned ioc,
-                                   size_t plen,
+                                   struct iov_iter *from,
                                    key_serial_t ringid)
 {
         const struct cred *cred = current_cred();
         struct request_key_auth *rka;
         struct key *instkey, *dest_keyring;
+        size_t plen = from ? iov_iter_count(from) : 0;
         void *payload;
         long ret;
-        bool vm = false;
 
         kenter("%d,,%zu,%d", id, plen, ringid);
 
+        if (!plen)
+                from = NULL;
+
         ret = -EINVAL;
         if (plen > 1024 * 1024 - 1)
                 goto error;
@@ -1054,20 +1040,19 @@ long keyctl_instantiate_key_common(key_serial_t id,
         /* pull the payload in if one was supplied */
         payload = NULL;
 
-        if (payload_iov) {
+        if (from) {
                 ret = -ENOMEM;
                 payload = kmalloc(plen, GFP_KERNEL);
                 if (!payload) {
                         if (plen <= PAGE_SIZE)
                                 goto error;
-                        vm = true;
                         payload = vmalloc(plen);
                         if (!payload)
                                 goto error;
                 }
 
-                ret = copy_from_user_iovec(payload, payload_iov, ioc);
-                if (ret < 0)
+                ret = -EFAULT;
+                if (copy_from_iter(payload, plen, from) != plen)
                         goto error2;
         }
 
@@ -1089,10 +1074,7 @@ long keyctl_instantiate_key_common(key_serial_t id,
                 keyctl_change_reqkey_auth(NULL);
 
 error2:
-        if (!vm)
-                kfree(payload);
-        else
-                vfree(payload);
+        kvfree(payload);
 error:
         return ret;
 }
@@ -1112,15 +1094,19 @@ long keyctl_instantiate_key(key_serial_t id,
                             key_serial_t ringid)
 {
         if (_payload && plen) {
-                struct iovec iov[1] = {
-                        [0].iov_base = (void __user *)_payload,
-                        [0].iov_len  = plen
-                };
+                struct iovec iov;
+                struct iov_iter from;
+                int ret;
 
-                return keyctl_instantiate_key_common(id, iov, 1, plen, ringid);
+                ret = import_single_range(WRITE, (void __user *)_payload, plen,
+                                          &iov, &from);
+                if (unlikely(ret))
+                        return ret;
+
+                return keyctl_instantiate_key_common(id, &from, ringid);
         }
 
-        return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
+        return keyctl_instantiate_key_common(id, NULL, ringid);
 }
 
 /*
@@ -1138,29 +1124,19 @@ long keyctl_instantiate_key_iov(key_serial_t id,
                                 key_serial_t ringid)
 {
         struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+        struct iov_iter from;
         long ret;
 
-        if (!_payload_iov || !ioc)
-                goto no_payload;
+        if (!_payload_iov)
+                ioc = 0;
 
-        ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
-                                    ARRAY_SIZE(iovstack), iovstack, &iov);
+        ret = import_iovec(WRITE, _payload_iov, ioc,
+                                    ARRAY_SIZE(iovstack), &iov, &from);
         if (ret < 0)
-                goto err;
-        if (ret == 0)
-                goto no_payload_free;
-
-        ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
-err:
-        if (iov != iovstack)
-                kfree(iov);
+                return ret;
+        ret = keyctl_instantiate_key_common(id, &from, ringid);
+        kfree(iov);
         return ret;
-
-no_payload_free:
-        if (iov != iovstack)
-                kfree(iov);
-no_payload:
-        return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
 }
 
 /*