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-rw-r--r--net/core/page_pool.c10
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;