1 files changed, 47 insertions, 0 deletions

diff --git a/security/keys/compat.c b/security/keys/compat.c
index 17c99d0149ec..338b510e9027 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -12,9 +12,52 @@
 #include <linux/syscalls.h>
 #include <linux/keyctl.h>
 #include <linux/compat.h>
+#include <linux/slab.h>
 #include "internal.h"
 
 /*
+ * Instantiate a key with the specified compatibility 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 compat_keyctl_instantiate_key_iov(
+        key_serial_t id,
+        const struct compat_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 = compat_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);
+}
+
+/*
  * The key control system call, 32-bit compatibility version for 64-bit archs
  *
  * This should only be called if the 64-bit arch uses weird pointers in 32-bit
@@ -88,6 +131,10 @@ asmlinkage long compat_sys_keyctl(u32 option,
         case KEYCTL_REJECT:
                 return keyctl_reject_key(arg2, arg3, arg4, arg5);
 
+        case KEYCTL_INSTANTIATE_IOV:
+                return compat_keyctl_instantiate_key_iov(
+                        arg2, compat_ptr(arg3), arg4, arg5);
+
         default:
                 return -EOPNOTSUPP;
         }