Commit 4cf949c7 authored by Zack Rusin's avatar Zack Rusin
Browse files

drm/vmwgfx: Validate the box size for the snooped cursor 



Invalid userspace dma surface copies could potentially overflow
the memcpy from the surface to the snooped image leading to crashes.
To fix it the dimensions of the copybox have to be validated
against the expected size of the snooped cursor.

Signed-off-by: default avatarZack Rusin <zackr@vmware.com>
Fixes: 2ac86371 ("vmwgfx: Snoop DMA transfers with non-covering sizes")
Cc: <stable@vger.kernel.org> # v3.2+
Reviewed-by: default avatarMichael Banack <banackm@vmware.com>
Reviewed-by: default avatarMartin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026031936.1004280-1-zack@kde.org
parent 4dba27f1

drivers/gpu/drm/vmwgfx/vmwgfx_kms.c

+2 −1
Original line number Diff line number Diff line
@@ -393,7 +393,8 @@ void vmw_kms_cursor_snoop(struct vmw_surface *srf, 
	if (cmd->dma.guest.ptr.offset % PAGE_SIZE ||

	    box->x != 0    || box->y != 0    || box->z != 0    ||

	    box->srcx != 0 || box->srcy != 0 || box->srcz != 0 ||

	    box->d != 1    || box_count != 1) {

	    box->d != 1    || box_count != 1 ||

	    box->w > 64 || box->h > 64) {

		/* TODO handle none page aligned offsets */

		/* TODO handle more dst & src != 0 */

		/* TODO handle more then one copy */