--- /dev/null
+From de066e116306baf3a6a62691ac63cfc0b1dabddb Mon Sep 17 00:00:00 2001
+From: Daniel Vetter <daniel.vetter@ffwll.ch>
+Date: Mon, 22 Feb 2021 11:06:43 +0100
+Subject: drm/compat: Clear bounce structures
+
+From: Daniel Vetter <daniel.vetter@ffwll.ch>
+
+commit de066e116306baf3a6a62691ac63cfc0b1dabddb upstream.
+
+Some of them have gaps, or fields we don't clear. Native ioctl code
+does full copies plus zero-extends on size mismatch, so nothing can
+leak. But compat is more hand-rolled so need to be careful.
+
+None of these matter for performance, so just memset.
+
+Also I didn't fix up the CONFIG_DRM_LEGACY or CONFIG_DRM_AGP ioctl, those
+are security holes anyway.
+
+Acked-by: Maxime Ripard <mripard@kernel.org>
+Reported-by: syzbot+620cf21140fc7e772a5d@syzkaller.appspotmail.com # vblank ioctl
+Cc: syzbot+620cf21140fc7e772a5d@syzkaller.appspotmail.com
+Cc: stable@vger.kernel.org
+Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
+Link: https://patchwork.freedesktop.org/patch/msgid/20210222100643.400935-1-daniel.vetter@ffwll.ch
+(cherry picked from commit e926c474ebee404441c838d18224cd6f246a71b7)
+Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/drm_ioc32.c | 11 +++++++++++
+ 1 file changed, 11 insertions(+)
+
+--- a/drivers/gpu/drm/drm_ioc32.c
++++ b/drivers/gpu/drm/drm_ioc32.c
+@@ -96,6 +96,8 @@ static int compat_drm_version(struct fil
+ if (copy_from_user(&v32, (void __user *)arg, sizeof(v32)))
+ return -EFAULT;
+
++ memset(&v, 0, sizeof(v));
++
+ v = (struct drm_version) {
+ .name_len = v32.name_len,
+ .name = compat_ptr(v32.name),
+@@ -134,6 +136,9 @@ static int compat_drm_getunique(struct f
+
+ if (copy_from_user(&uq32, (void __user *)arg, sizeof(uq32)))
+ return -EFAULT;
++
++ memset(&uq, 0, sizeof(uq));
++
+ uq = (struct drm_unique){
+ .unique_len = uq32.unique_len,
+ .unique = compat_ptr(uq32.unique),
+@@ -260,6 +265,8 @@ static int compat_drm_getclient(struct f
+ if (copy_from_user(&c32, argp, sizeof(c32)))
+ return -EFAULT;
+
++ memset(&client, 0, sizeof(client));
++
+ client.idx = c32.idx;
+
+ err = drm_ioctl_kernel(file, drm_getclient, &client, DRM_UNLOCKED);
+@@ -842,6 +849,8 @@ static int compat_drm_wait_vblank(struct
+ if (copy_from_user(&req32, argp, sizeof(req32)))
+ return -EFAULT;
+
++ memset(&req, 0, sizeof(req));
++
+ req.request.type = req32.request.type;
+ req.request.sequence = req32.request.sequence;
+ req.request.signal = req32.request.signal;
+@@ -879,6 +888,8 @@ static int compat_drm_mode_addfb2(struct
+ struct drm_mode_fb_cmd2 req64;
+ int err;
+
++ memset(&req64, 0, sizeof(req64));
++
+ if (copy_from_user(&req64, argp,
+ offsetof(drm_mode_fb_cmd232_t, modifier)))
+ return -EFAULT;