agp: fix OOM and buffer overflow

[uclinux-h8/linux.git] / drivers / char / agp / generic.c

diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index 012cba0..850a643 100644 (file)
--- 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) {