[v2,13/16] mm/page_alloc: init local variable buddy_pfn

Commit Message

Miaohe Lin Sept. 16, 2022, 7:22 a.m. UTC

The local variable buddy_pfn could be passed to buddy_merge_likely()
without initialization if the passed in order is MAX_ORDER - 1. This
looks buggy but buddy_pfn won't be used in this case as there's a
order >= MAX_ORDER - 2 check. Init buddy_pfn to 0 anyway to avoid
possible future misuse.

Signed-off-by: Miaohe Lin <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Reviewed-by: Anshuman Khandual <[e-mail]>
Reviewed-by: Oscar Salvador <[e-mail]>
---
 mm/page_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 67ec8a2e1db2..652b3d766003 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1113,7 +1113,7 @@  static inline void __free_one_page(struct page *page,
 		int migratetype, fpi_t fpi_flags)
 {
 	struct capture_control *capc = task_capc(zone);
-	unsigned long buddy_pfn;
+	unsigned long buddy_pfn = 0;
 	unsigned long combined_pfn;
 	struct page *buddy;
 	bool to_tail;