1 files changed, 9 insertions, 2 deletions

diff --git a/arch/um/kernel/tt/uaccess_user.c b/arch/um/kernel/tt/uaccess_user.c
index f01475512ecb..8c220f054b61 100644
--- a/arch/um/kernel/tt/uaccess_user.c
+++ b/arch/um/kernel/tt/uaccess_user.c
@@ -22,8 +22,15 @@ int __do_copy_from_user(void *to, const void *from, int n,
                                __do_copy, &faulted);
         TASK_REGS(get_current())->tt = save;
 
-        if(!faulted) return(0);
-        else return(n - (fault - (unsigned long) from));
+        if(!faulted)
+                return 0;
+        else if (fault)
+                return n - (fault - (unsigned long) from);
+        else
+                /* In case of a general protection fault, we don't have the
+                 * fault address, so NULL is used instead. Pretend we didn't
+                 * copy anything. */
+                return n;
 }
 
 static void __do_strncpy(void *dst, const void *src, int count)