Currently, kasan_free_nondeferred_pages()->kasan_free_pages() is called after debug_pagealloc_unmap_pages(). This causes a crash when debug_pagealloc is enabled, as HW_TAGS KASAN can't set tags on an unmapped page. This patch puts kasan_free_nondeferred_pages() before debug_pagealloc_unmap_pages(). Besides fixing the crash, this also makes the annotation order consistent with debug_pagealloc_map_pages() preceding kasan_alloc_pages(). Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> --- mm/page_alloc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c89e7b107514..54bc237fd319 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1311,10 +1311,14 @@ static __always_inline bool free_pages_prepare(struct page *page, */ arch_free_page(page, order); - debug_pagealloc_unmap_pages(page, 1 << order); - + /* + * With hardware tag-based KASAN, memory tags must be set + * before unmapping the page with debug_pagealloc. + */ kasan_free_nondeferred_pages(page, order, fpi_flags); + debug_pagealloc_unmap_pages(page, 1 << order); + return true; } -- 2.30.1.766.gb4fecdf3b7-goog
