Hi, thank you for this patch. Murray McAllister reported this one a couple of months ago, and this is already in our queue. Sinclair On Fri, Mar 24, 2017 at 04:37:10PM +0100, Vladis Dronov wrote: > In vmw_surface_define_ioctl(), a num_sizes parameter is assigned a > user-controlled value which is not checked for zero. It is used in > a call to kmalloc() which returns ZERO_SIZE_PTR. Later ZERO_SIZE_PTR > is dereferenced which leads to a GPF and possibly to a kernel panic. > Add the check for zero to avoid this. > > Reference: https://urldefense.proofpoint.com/v2/url?u=https-3A__bugzilla.redhat.com_show-5Fbug.cgi-3Fid-3D1435719&d=DwIBAg&c=uilaK90D4TOVoH58JNXRgQ&r=HaJ2a6NYExoV0cntAYcoqA&m=OW9cIAAez9eRIxEYMaToDu2szuR_YrfQcOzAH6L8dXo&s=-3P2pG3n1YW6-8NG6mLC7kyxmx7mMxJmXgY79ZgQeo4&e= > Signed-off-by: Vladis Dronov <vdronov@xxxxxxxxxx> > --- > drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c > index b445ce9..42840cc 100644 > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c > @@ -716,8 +716,8 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data, > for (i = 0; i < DRM_VMW_MAX_SURFACE_FACES; ++i) > num_sizes += req->mip_levels[i]; > > - if (num_sizes > DRM_VMW_MAX_SURFACE_FACES * > - DRM_VMW_MAX_MIP_LEVELS) > + if (num_sizes <= 0 || > + num_sizes > DRM_VMW_MAX_SURFACE_FACES * DRM_VMW_MAX_MIP_LEVELS) > return -EINVAL; > > size = vmw_user_surface_size + 128 + > -- > 2.9.3 > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
