Merge branch 'torvalds:master' into master

1 files changed, 9 insertions, 1 deletions

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 5e4eb45b139c..8ab7b402244c 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -634,7 +634,15 @@ bool page_pool_return_skb_page(struct page *page)
 	struct page_pool *pp;
 
 	page = compound_head(page);
-	if (unlikely(page->pp_magic != PP_SIGNATURE))
+
+	/* page->pp_magic is OR'ed with PP_SIGNATURE after the allocation
+	 * in order to preserve any existing bits, such as bit 0 for the
+	 * head page of compound page and bit 1 for pfmemalloc page, so
+	 * mask those bits for freeing side when doing below checking,
+	 * and page_is_pfmemalloc() is checked in __page_pool_put_page()
+	 * to avoid recycling the pfmemalloc page.
+	 */
+	if (unlikely((page->pp_magic & ~0x3UL) != PP_SIGNATURE))
 		return false;
 
 	pp = page->pp;