Changeset 0941e9ae in mainline

Timestamp:

2012-11-05T20:17:17Z (12 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

94795812

Parents:

082b7f1

Message:

Test for addition overflow of area's base and size.

Location:

kernel/generic

Files:

• include/macros.h (modified) (1 diff)
• src/mm/as.c (modified) (4 diffs)

kernel/generic/include/macros.h

@@ -130 +130 @@
             | ((((uint64_t) (up)) & UINT32_C(0xffffffff)) << 32))
 
+/* Test for result wrap-around into positive numbers. */
+#define overflows_add(a, b) \
+        (((a) + (b) < (a)) && ((a) + (b)))
+
 /** Pseudorandom generator
  *

kernel/generic/src/mm/as.c

@@ -299 +299 @@
         ASSERT((addr % PAGE_SIZE) == 0);
         ASSERT(mutex_locked(&as->lock));
+        ASSERT(!overflows_add(addr, P2SZ(count)));
         
         /*
@@ -513 +514 @@
         if (size == 0)
                 return NULL;
-        
+
         size_t pages = SIZE2FRAMES(size);
         
@@ -531 +532 @@
                 }
         }
+
+        if (overflows_add(*base, size))
+                return NULL;
 
         if (!check_area_conflicts(as, *base, pages, guarded, NULL)) {
@@ -810 +814 @@
                 /*
                  * Growing the area.
+                 */
+
+                if (overflows_add(address, P2SZ(pages)))
+                        return EINVAL;
+
+                /*
                  * Check for overlaps with other address space areas.
                  */