1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index 012cba0d6d96..b072648dc3f6 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -115,6 +115,9 @@ static struct agp_memory *agp_create_user_memory(unsigned long num_agp_pages)
         struct agp_memory *new;
         unsigned long alloc_size = num_agp_pages*sizeof(struct page *);
 
+        if (INT_MAX/sizeof(struct page *) < num_agp_pages)
+                return NULL;
+
         new = kzalloc(sizeof(struct agp_memory), GFP_KERNEL);
         if (new == NULL)
                 return NULL;
@@ -234,11 +237,14 @@ struct agp_memory *agp_allocate_memory(struct agp_bridge_data *bridge,
         int scratch_pages;
         struct agp_memory *new;
         size_t i;
+        int cur_memory;
 
         if (!bridge)
                 return NULL;
 
-        if ((atomic_read(&bridge->current_memory_agp) + page_count) > bridge->max_memory_agp)
+        cur_memory = atomic_read(&bridge->current_memory_agp);
+        if ((cur_memory + page_count > bridge->max_memory_agp) ||
+            (cur_memory + page_count < page_count))
                 return NULL;
 
         if (type >= AGP_USER_TYPES) {
@@ -1089,8 +1095,8 @@ int agp_generic_insert_memory(struct agp_memory * mem, off_t pg_start, int type)
                 return -EINVAL;
         }
 
-        /* AK: could wrap */
-        if ((pg_start + mem->page_count) > num_entries)
+        if (((pg_start + mem->page_count) > num_entries) ||
+            ((pg_start + mem->page_count) < pg_start))
                 return -EINVAL;
 
         j = pg_start;
@@ -1124,7 +1130,7 @@ int agp_generic_remove_memory(struct agp_memory *mem, off_t pg_start, int type)
 {
         size_t i;
         struct agp_bridge_data *bridge;
-        int mask_type;
+        int mask_type, num_entries;
 
         bridge = mem->bridge;
         if (!bridge)
@@ -1136,6 +1142,11 @@ int agp_generic_remove_memory(struct agp_memory *mem, off_t pg_start, int type)
         if (type != mem->type)
                 return -EINVAL;
 
+        num_entries = agp_num_entries();
+        if (((pg_start + mem->page_count) > num_entries) ||
+            ((pg_start + mem->page_count) < pg_start))
+                return -EINVAL;
+
         mask_type = bridge->driver->agp_type_to_mask_type(bridge, type);
         if (mask_type != 0) {
                 /* The generic routines know nothing of memory types */