From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] drm/i915/gvt/fb_decoder: Fix out-of-bounds read Date: Sat, 9 Dec 2017 00:37:59 -0600 Message-ID: <20171209063759.GA8672@embeddedor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Zhenyu Wang , Zhi Wang , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie Cc: intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: dri-devel@lists.freedesktop.org In case function skl_format_to_drm returns -EINVAL, fmt turns into a huge number as fmt is of type u32, hence there is an out-of-bounds read when using fmt as an index for array skl_pixel_formats at line 225: plane->bpp = skl_pixel_formats[fmt].bpp; Fix this by comparing the value returned by function skl_format_to_drm against the size of array skl_pixel_formats, so in case it is greater than or equal to the number of items contained in skl_pixel_formats, print an error message and return -EINVAL. Addresses-Coverity-ID: 1462495 Addresses-Coverity-ID: 1462502 ("Out-of-bounds read") Fixes: 9f31d1063b43 ("drm/i915/gvt: Add framebuffer decoder support") Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/i915/gvt/fb_decoder.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/i915/gvt/fb_decoder.c b/drivers/gpu/drm/i915/gvt/fb_decoder.c index 72f4217..aed578b 100644 --- a/drivers/gpu/drm/i915/gvt/fb_decoder.c +++ b/drivers/gpu/drm/i915/gvt/fb_decoder.c @@ -222,6 +222,12 @@ int intel_vgpu_decode_primary_plane(struct intel_vgpu *vgpu, val & PLANE_CTL_ORDER_RGBX, val & PLANE_CTL_ALPHA_MASK, val & PLANE_CTL_YUV422_ORDER_MASK); + + if (fmt >= ARRAY_SIZE(skl_pixel_formats)) { + gvt_vgpu_err("Out-of-bounds pixel format index\n"); + return -EINVAL; + } + plane->bpp = skl_pixel_formats[fmt].bpp; plane->drm_format = skl_pixel_formats[fmt].drm_format; } else { -- 2.7.4