From nobody Sun May 5 11:26:21 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1488871709528166.43976124444657; Mon, 6 Mar 2017 23:28:29 -0800 (PST) Received: from localhost ([::1]:47970 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cl9Xo-0007Wp-8C for importer@patchew.org; Tue, 07 Mar 2017 02:28:28 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44981) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cl9RW-0002eK-Mp for qemu-devel@nongnu.org; Tue, 07 Mar 2017 02:21:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cl9RT-0006a6-Ig for qemu-devel@nongnu.org; Tue, 07 Mar 2017 02:21:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37746) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cl9RT-0006ZY-CI for qemu-devel@nongnu.org; Tue, 07 Mar 2017 02:21:55 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D12838123E; Tue, 7 Mar 2017 07:21:54 +0000 (UTC) Received: from localhost.localdomain ([10.33.36.4]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v277LoOe025061 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 7 Mar 2017 02:21:52 -0500 From: P J P To: Qemu Developers Date: Tue, 7 Mar 2017 12:51:47 +0530 Message-Id: <20170307072147.1425-1-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 07 Mar 2017 07:21:54 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3] linux-user: allocate heap memory for execve arguments X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Riku Voipio , Prasad J Pandit , Jann Horn Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Prasad J Pandit Arguments passed to execve(2) call from user program could be large, allocating stack memory for them via alloca(3) call would lead to bad behaviour. Use 'g_new0' to allocate memory for such arguments. Reported-by: Jann Horn Signed-off-by: Prasad J Pandit Reviewed-by: Eric Blake --- linux-user/syscall.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) Update: use g_new0 instead of g_malloc0 -> https://lists.gnu.org/archive/html/qemu-devel/2017-03/msg01193.html diff --git a/linux-user/syscall.c b/linux-user/syscall.c index cec8428..c672581 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -7926,8 +7926,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long = arg1, envc++; } - argp =3D alloca((argc + 1) * sizeof(void *)); - envp =3D alloca((envc + 1) * sizeof(void *)); + argp =3D g_new0(char *, argc + 1); + envp =3D g_new0(char *, envc + 1); for (gp =3D guest_argp, q =3D argp; gp; gp +=3D sizeof(abi_ulong), q++) { @@ -7988,6 +7988,9 @@ abi_long do_syscall(void *cpu_env, int num, abi_long = arg1, break; unlock_user(*q, addr, 0); } + + g_free(argp); + g_free(envp); } break; case TARGET_NR_chdir: -- 2.9.3