usercopy: avoid potentially undefined behavior in pointer math

[cascardo/linux.git] / mm / usercopy.c

diff --git a/mm/usercopy.c b/mm/usercopy.c
index 8ebae91..82f81df 100644 (file)
--- a/mm/usercopy.c
+++ b/mm/usercopy.c
@@ -124,7 +124,7 @@ static inline const char *check_kernel_text_object(const void *ptr,
 static inline const char *check_bogus_address(const void *ptr, unsigned long n)
 {
        /* Reject if object wraps past end of memory. */
-       if (ptr + n < ptr)
+       if ((unsigned long)ptr + n < (unsigned long)ptr)
                return "<wrapped address>";
 
        /* Reject if NULL or ZERO-allocation. */