From: Chen Gang Subject: [PATCH] target-ppc: kvm: Fix memory overflow issue about strncat() Date: Mon, 13 Oct 2014 22:36:02 +0800 Message-ID: <543BE352.3080609@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: qemu-ppc@nongnu.org, kvm@vger.kernel.org, qemu-devel , qemu-trivial@nongnu.org To: agraf@suse.de, pbonzini@redhat.com Return-path: Received: from mail-pd0-f170.google.com ([209.85.192.170]:53963 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753063AbaJMOaL (ORCPT ); Mon, 13 Oct 2014 10:30:11 -0400 Received: by mail-pd0-f170.google.com with SMTP id p10so5778005pdj.1 for ; Mon, 13 Oct 2014 07:30:10 -0700 (PDT) Sender: kvm-owner@vger.kernel.org List-ID: strncat() will append additional '\0' to destination buffer, so need additional 1 byte for it, or may cause memory overflow, just like other area within QEMU have done. Signed-off-by: Chen Gang --- target-ppc/kvm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index 9c23c6b..66e7ce5 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -1794,8 +1794,8 @@ static uint64_t kvmppc_read_int_cpu_dt(const char *propname) return -1; } - strncat(buf, "/", sizeof(buf) - strlen(buf)); - strncat(buf, propname, sizeof(buf) - strlen(buf)); + strncat(buf, "/", sizeof(buf) - strlen(buf) - 1); + strncat(buf, propname, sizeof(buf) - strlen(buf) - 1); f = fopen(buf, "rb"); if (!f) { -- 1.9.3