Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933722AbdDFQAR (ORCPT ); Thu, 6 Apr 2017 12:00:17 -0400 Received: from mail.kernel.org ([198.145.29.136]:57904 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933630AbdDFQAE (ORCPT ); Thu, 6 Apr 2017 12:00:04 -0400 MIME-Version: 1.0 In-Reply-To: <1491424561-7187-1-git-send-email-minipli@googlemail.com> References: <1491424561-7187-1-git-send-email-minipli@googlemail.com> From: Andy Lutomirski Date: Thu, 6 Apr 2017 08:59:38 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] x86/vdso: ensure vdso32_enabled gets set to valid values only To: Mathias Krause Cc: X86 ML , "linux-kernel@vger.kernel.org" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Roland McGrath Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 625 Lines: 12 On Wed, Apr 5, 2017 at 1:36 PM, Mathias Krause wrote: > If either via kernel command line 'vdso32=' or via 'sysctl abi.vsyscall32' > vdso32_enabled gets set to a value below 0 or above 1, load_vdso32() won't > map the vDSO but ARCH_DLINFO_IA32 would still pass an AT_SYSINFO_EHDR > auxiliary vector, however with a NULL pointer. That'll make any program > trying to make use of it fail with a segmentation fault. At least musl > makes use of it if the kernel provides it. > > Ensure vdso32_enabled gets set to valid values only to fix this corner > case. Acked-by: Andy Lutomirski