[PATCH] kmsan: test: check vmalloc return value before use

[Liu Jing]

In test_init_vmalloc(), the return value of vmalloc() is used directly
without a NULL check. If vmalloc() fails under memory pressure, the
subsequent buf[0] = 1 and memset() calls will dereference a NULL
pointer and cause a kernel panic.

Add a NULL check immediately after vmalloc() and skip the test if
allocation fails.

Signed-off-by: Liu Jing <liujing@xxxxxxxxxxxxxxxxxxxx>
---
 mm/kmsan/kmsan_test.c | 6 ++++++
 1 file changed, 6 insertion(+), 0 deletion(-)

--- a/mm/kmsan/kmsan_test.c
+++ b/mm/kmsan/kmsan_test.c
@@ -352,6 +352,12 @@
 
 	kunit_info(test, "vmalloc buffer can be initialized (no reports)\n");
 	buf = vmalloc(PAGE_SIZE * npages);
+
+	if (!buf) {
+		kunit_skip(test, "vmalloc failed, skipping test\n");
+		return;
+	}
+
 	buf[0] = 1;
 	memset(buf, 0xfe, PAGE_SIZE * npages);
 	USE(buf[0]);

--
2.43.0