From patchwork Wed May 22 13:47:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 1103347 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 458DVm6JJtz9s1c for ; Wed, 22 May 2019 23:48:32 +1000 (AEST) Received: from localhost ([127.0.0.1]:43646 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hTRba-0006to-74 for incoming@patchwork.ozlabs.org; Wed, 22 May 2019 09:48:30 -0400 Received: from eggs.gnu.org ([209.51.188.92]:43450) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hTRac-0006sD-9k for qemu-devel@nongnu.org; Wed, 22 May 2019 09:47:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hTRab-0002ak-7h for qemu-devel@nongnu.org; Wed, 22 May 2019 09:47:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36104) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hTRab-0002aF-0Q for qemu-devel@nongnu.org; Wed, 22 May 2019 09:47:29 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 606B85D5FF for ; Wed, 22 May 2019 13:47:28 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-28.ams2.redhat.com [10.36.116.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 313741001281 for ; Wed, 22 May 2019 13:47:28 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id D63CD1132B6C; Wed, 22 May 2019 15:47:26 +0200 (CEST) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Wed, 22 May 2019 15:47:24 +0200 Message-Id: <20190522134726.19225-4-armbru@redhat.com> In-Reply-To: <20190522134726.19225-1-armbru@redhat.com> References: <20190522134726.19225-1-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 22 May 2019 13:47:28 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 3/5] gdbstub: Reject invalid RLE repeat counts 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: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" "Debugging with GDB / Appendix E GDB Remote Serial Protocol / Overview" specifies "The printable characters '#' and '$' or with a numeric value greater than 126 must not be used." gdb_read_byte() only rejects values < 32. This is wrong. Impact depends on the caller: * gdb_handlesig() passes a char. Incorrectly accepts '#', '$' and '\127'. * gdb_chr_receive() passes an uint8_t. Additionally accepts characters with the most-significant bit set. Correct the validity check to match the specification. Signed-off-by: Markus Armbruster Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20190514180311.16028-4-armbru@redhat.com> --- gdbstub.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/gdbstub.c b/gdbstub.c index d54abd17cc..c41eb1de07 100644 --- a/gdbstub.c +++ b/gdbstub.c @@ -2064,7 +2064,11 @@ static void gdb_read_byte(GDBState *s, int ch) } break; case RS_GETLINE_RLE: - if (ch < ' ') { + /* + * Run-length encoding is explained in "Debugging with GDB / + * Appendix E GDB Remote Serial Protocol / Overview". + */ + if (ch < ' ' || ch == '#' || ch == '$' || ch > 126) { /* invalid RLE count encoding */ trace_gdbstub_err_invalid_repeat((uint8_t)ch); s->state = RS_GETLINE;