module/decompress: Avoid open-coded kvrealloc()

Replace open-coded allocate/copy with kvrealloc().

Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
index 474e68f0f0634913625003bbdf6610b23fb7ff15..36f52a232a120e748775ad4199e736832c669497 100644 (file)
--- a/kernel/module/decompress.c
+++ b/kernel/module/decompress.c
@@ -17,16 +17,16 @@
 static int module_extend_max_pages(struct load_info *info, unsigned int extent)
 {
        struct page **new_pages;
+       unsigned int new_max = info->max_pages + extent;
 
-       new_pages = kvmalloc_array(info->max_pages + extent,
-                                  sizeof(info->pages), GFP_KERNEL);
+       new_pages = kvrealloc(info->pages,
+                             size_mul(new_max, sizeof(*info->pages)),
+                             GFP_KERNEL);
        if (!new_pages)
                return -ENOMEM;
 
-       memcpy(new_pages, info->pages, info->max_pages * sizeof(info->pages));
-       kvfree(info->pages);
        info->pages = new_pages;
-       info->max_pages += extent;
+       info->max_pages = new_max;
 
        return 0;
 }