Patch "drm/vmwgfx: Fix invalid reads in fence signaled events" has been added to the 4.19-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    drm/vmwgfx: Fix invalid reads in fence signaled events

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-vmwgfx-fix-invalid-reads-in-fence-signaled-events.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From a37ef7613c00f2d72c8fc08bd83fb6cc76926c8c Mon Sep 17 00:00:00 2001
From: Zack Rusin <zack.rusin at broadcom.com>
Date: Thu, 25 Apr 2024 15:27:48 -0400
Subject: drm/vmwgfx: Fix invalid reads in fence signaled events

From: Zack Rusin <zack.rusin at broadcom.com>

commit a37ef7613c00f2d72c8fc08bd83fb6cc76926c8c upstream.

Correctly set the length of the drm_event to the size of the structure
that's actually used.

The length of the drm_event was set to the parent structure instead of
to the drm_vmw_event_fence which is supposed to be read. drm_read
uses the length parameter to copy the event to the user space thus
resuling in oob reads.

Signed-off-by: Zack Rusin <zack.rusin at broadcom.com>
Fixes: 8b7de6aa8468 ("vmwgfx: Rework fence event action")
Reported-by: zdi-disclosures at trendmicro.com # ZDI-CAN-23566
Cc: David Airlie <airlied at gmail.com>
CC: Daniel Vetter <daniel at ffwll.ch>
Cc: Zack Rusin <zack.rusin at broadcom.com>
Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list at broadcom.com>
Cc: dri-devel at lists.freedesktop.org
Cc: linux-kernel at vger.kernel.org
Cc: <stable at vger.kernel.org> # v3.4+
Reviewed-by: Maaz Mombasawala <maaz.mombasawala at broadcom.com>
Reviewed-by: Martin Krastev <martin.krastev at broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240425192748.1761522-1-zack.rusin@broadcom.com
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_fence.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
@@ -1064,7 +1064,7 @@ static int vmw_event_fence_action_create
 	}
 
 	event->event.base.type = DRM_VMW_EVENT_FENCE_SIGNALED;
-	event->event.base.length = sizeof(*event);
+	event->event.base.length = sizeof(event->event);
 	event->event.user_data = user_data;
 
 	ret = drm_event_reserve_init(dev, file_priv, &event->base, &event->event.base);


Patches currently in stable-queue which might be from zack.rusin at broadcom.com are

queue-4.19/drm-vmwgfx-fix-invalid-reads-in-fence-signaled-events.patch