This is a note to let you know that I've just added the patch titled drm/vmwgfx: avoid calling vzalloc with a 0 size in vmw_get_cap_3d_ioctl() to the 4.9-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-avoid-calling-vzalloc-with-a-0-size-in-vmw_get_cap_3d_ioctl.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 63774069d9527a1aeaa4aa20e929ef5e8e9ecc38 Mon Sep 17 00:00:00 2001 From: Murray McAllister <murray.mcallister@xxxxxxxxxxxxxxx> Date: Mon, 27 Mar 2017 11:15:12 +0200 Subject: drm/vmwgfx: avoid calling vzalloc with a 0 size in vmw_get_cap_3d_ioctl() From: Murray McAllister <murray.mcallister@xxxxxxxxxxxxxxx> commit 63774069d9527a1aeaa4aa20e929ef5e8e9ecc38 upstream. In vmw_get_cap_3d_ioctl(), a user can supply 0 for a size that is used in vzalloc(). This eventually calls dump_stack() (in warn_alloc()), which can leak useful addresses to dmesg. Add check to avoid a size of 0. Signed-off-by: Murray McAllister <murray.mcallister@xxxxxxxxxxxxxxx> Reviewed-by: Sinclair Yeh <syeh@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c @@ -186,7 +186,7 @@ int vmw_get_cap_3d_ioctl(struct drm_devi bool gb_objects = !!(dev_priv->capabilities & SVGA_CAP_GBOBJECTS); struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv); - if (unlikely(arg->pad64 != 0)) { + if (unlikely(arg->pad64 != 0 || arg->max_size == 0)) { DRM_ERROR("Illegal GET_3D_CAP argument.\n"); return -EINVAL; } Patches currently in stable-queue which might be from murray.mcallister@xxxxxxxxxxxxxxx are queue-4.9/drm-vmwgfx-avoid-calling-vzalloc-with-a-0-size-in-vmw_get_cap_3d_ioctl.patch queue-4.9/drm-vmwgfx-null-pointer-dereference-in-vmw_surface_define_ioctl.patch