mm: kmsan: add test_uninit_page

Test that pages allocated with alloc_page() are uninitialized by default.

Link: https://lkml.kernel.org/r/20260113091151.4035013-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c
index ba44bf2072bbefa17ff76f7f793a91886e13ede1..81e642db6e239ba9700318d3a7012b8e404d5ffc 100644 (file)
--- a/mm/kmsan/kmsan_test.c
+++ b/mm/kmsan/kmsan_test.c
@@ -378,6 +378,20 @@ static void test_uaf(struct kunit *test)
        KUNIT_EXPECT_TRUE(test, report_matches(&expect));
 }
 
+static void test_uninit_page(struct kunit *test)
+{
+       EXPECTATION_UNINIT_VALUE(expect);
+       struct page *page;
+       int *ptr;
+
+       kunit_info(test, "uninitialized page allocation (UMR report)\n");
+       page = alloc_pages(GFP_KERNEL, 0);
+       ptr = page_address(page);
+       USE(*ptr);
+       __free_pages(page, 0);
+       KUNIT_EXPECT_TRUE(test, report_matches(&expect));
+}
+
 static volatile char *test_uaf_pages_helper(int order, int offset)
 {
        struct page *page;
@@ -727,6 +741,7 @@ static struct kunit_case kmsan_test_cases[] = {
        KUNIT_CASE(test_uninit_kmsan_check_memory),
        KUNIT_CASE(test_init_kmsan_vmap_vunmap),
        KUNIT_CASE(test_init_vmalloc),
+       KUNIT_CASE(test_uninit_page),
        KUNIT_CASE(test_uaf),
        KUNIT_CASE(test_uaf_pages),
        KUNIT_CASE(test_uaf_high_order_pages),