From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760300Ab3BHUfA (ORCPT ); Fri, 8 Feb 2013 15:35:00 -0500 Received: from mail.tpi.com ([70.99.223.143]:3200 "EHLO mail.tpi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755334Ab3BHUe7 (ORCPT ); Fri, 8 Feb 2013 15:34:59 -0500 From: Tim Gardner To: linux-kernel@vger.kernel.org Cc: Tim Gardner , Konrad Rzeszutek Wilk , Jeremy Fitzhardinge , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, xen-devel@lists.xensource.com, virtualization@lists.linux-foundation.org, stable@vger.kernel.org Subject: [PATCH linux-next] xen/multicall: xen_mc_callback(): avoid buffer overflow Date: Fri, 8 Feb 2013 13:34:37 -0700 Message-Id: <1360355677-52442-1-git-send-email-tim.gardner@canonical.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This buffer overflow was introduced with 91e0c5f3dad47838cb2ecc1865ce789a0b7182b1 (2.6.24). Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Cc: stable@vger.kernel.org Signed-off-by: Tim Gardner --- This patch applies cleanly to 3.1.10 and newer. Requires a backport for 2.6.24-3.2.y arch/x86/xen/multicalls.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c index 0d82003..5270407 100644 --- a/arch/x86/xen/multicalls.c +++ b/arch/x86/xen/multicalls.c @@ -195,9 +195,10 @@ void xen_mc_callback(void (*fn)(void *), void *data) struct mc_buffer *b = &__get_cpu_var(mc_buffer); struct callback *cb; - if (b->cbidx == MC_BATCH) { + if (b->cbidx >= MC_BATCH) { trace_xen_mc_flush_reason(XEN_MC_FL_CALLBACK); xen_mc_flush(); + return; } trace_xen_mc_callback(fn, data); -- 1.7.9.5