[PATCH] initramfs_test: add NULL check for kmalloc in initramfs_test_fname_overrun

[longlong yan]

Add missing NULL check for kmalloc return value in
initramfs_test_fname_overrun(). Without this check, if kmalloc fails,
the subsequent memset() will dereference a NULL pointer, causing a
kernel crash.

Fixes: 83c0b27266ec ("initramfs_test: kunit tests for initramfs unpacking")
Signed-off-by: longlong yan <yanlonglong@xxxxxxxxxx>
---
 init/initramfs_test.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/init/initramfs_test.c b/init/initramfs_test.c
index 1fc990a66563..c7aab7e5383e 100644
--- a/init/initramfs_test.c
+++ b/init/initramfs_test.c
@@ -189,6 +189,9 @@ static void __init initramfs_test_fname_overrun(struct kunit *test)
 	 * are already available (e.g. no compression).
 	 */
 	cpio_srcbuf = kmalloc(CPIO_HDRLEN + PATH_MAX + 3, GFP_KERNEL);
+	if (!cpio_srcbuf)
+		return;
+
 	memset(cpio_srcbuf, 'B', CPIO_HDRLEN + PATH_MAX + 3);
 	/* limit overrun to avoid crashes / filp_open() ENAMETOOLONG */
 	cpio_srcbuf[CPIO_HDRLEN + strlen(c[0].fname) + 20] = '\0';
-- 
2.43.0