From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:54864 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754100AbeDFN1H (ORCPT ); Fri, 6 Apr 2018 09:27:07 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eyal Itkin , Daniel Vetter Subject: [PATCH 3.18 12/93] drm: udl: Properly check framebuffer mmap offsets Date: Fri, 6 Apr 2018 15:22:41 +0200 Message-Id: <20180406084225.501275097@linuxfoundation.org> In-Reply-To: <20180406084224.918716300@linuxfoundation.org> References: <20180406084224.918716300@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit 3b82a4db8eaccce735dffd50b4d4e1578099b8e8 upstream. The memmap options sent to the udl framebuffer driver were not being checked for all sets of possible crazy values. Fix this up by properly bounding the allowed values. Reported-by: Eyal Itkin Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20180321154553.GA18454@kroah.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/udl/udl_fb.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/udl/udl_fb.c +++ b/drivers/gpu/drm/udl/udl_fb.c @@ -256,10 +256,15 @@ static int udl_fb_mmap(struct fb_info *i { unsigned long start = vma->vm_start; unsigned long size = vma->vm_end - vma->vm_start; - unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; + unsigned long offset; unsigned long page, pos; - if (offset + size > info->fix.smem_len) + if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT)) + return -EINVAL; + + offset = vma->vm_pgoff << PAGE_SHIFT; + + if (offset > info->fix.smem_len || size > info->fix.smem_len - offset) return -EINVAL; pos = (unsigned long)info->fix.smem_start + offset;