udl-kms: fix crash due to uninitialized memory

commit 09a00abe3a9941c2715ca83eb88172cd2f54d8fd upstream.

We must use kzalloc when allocating the fb_deferred_io structure.
Otherwise, the field first_io is undefined and it causes a crash.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
index 29bd801..0c648ef 100644 (file)
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@@ -341,7 +341,7 @@ static int udl_fb_open(struct fb_info *info, int user)
 
                struct fb_deferred_io *fbdefio;
 
-               fbdefio = kmalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
+               fbdefio = kzalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
 
                if (fbdefio) {
                        fbdefio->delay = DL_DEFIO_WRITE_DELAY;