drm/modes: Avoid divide by zero harder in drm_mode_vrefresh()

commit 9398332f23fab10c5ec57c168b44e72997d6318e upstream.

drm_mode_vrefresh() is trying to avoid divide by zero
by checking whether htotal or vtotal are zero. But we may
still end up with a div-by-zero of vtotal*htotal*...

BUG=b/390600266
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2024-56369 in the Linux kernel.

cos-patch: security-moderate
Cc: stable@vger.kernel.org
Reported-by: syzbot+622bba18029bcde672e1@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=622bba18029bcde672e1
Change-Id: Ie150d435a062f985397dbc514b98ea3cc62c9751
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241129042629.18280-2-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kernel CVE Triage Automation <cloud-image-kernel-cve-triage-automation@prod.google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/90901
Reviewed-by: Kevin Berry <kpberry@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Shuo Yang <gshuoy@google.com>
1 file changed