From nobody Mon Feb 9 16:53:03 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1684314717960938.2517507719672; Wed, 17 May 2023 02:11:57 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pzDBQ-0000FQ-S4; Wed, 17 May 2023 05:10:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pzDBM-00007t-79; Wed, 17 May 2023 05:10:52 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pzDBG-0006LN-DC; Wed, 17 May 2023 05:10:51 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 0FCD26827; Wed, 17 May 2023 12:10:43 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 67FDF5EF3; Wed, 17 May 2023 12:10:42 +0300 (MSK) Received: (nullmailer pid 3626669 invoked by uid 1000); Wed, 17 May 2023 09:10:42 -0000 From: Michael Tokarev To: qemu-stable@nongnu.org Cc: qemu-devel@nongnu.org, Paolo Bonzini Subject: [PATCH v7.2.3 01/30] vnc: avoid underflow when accessing user-provided address Date: Wed, 17 May 2023 12:10:13 +0300 Message-Id: <20230517091042.3626593-1-mjt@msgid.tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01, T_SPF_HELO_TEMPERROR=0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1684314718485100001 Content-Type: text/plain; charset="utf-8" From: Paolo Bonzini If hostlen is zero, there is a possibility that addrstr[hostlen - 1] underflows and, if a closing bracked is there, hostlen - 2 is passed to g_strndup() on the next line. If websocket=3D=3Dfalse then addrstr[0] would be a colon, but if websocket=3D=3Dtrue this could in principle happen. Fix it by checking hostlen. Reported by Coverity. Signed-off-by: Paolo Bonzini (cherry picked from commit 3f9c41c5df9617510d8533cf6588172efb3df34b) Signed-off-by: Michael Tokarev --- ui/vnc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ui/vnc.c b/ui/vnc.c index 88f55cbf3c..1856d57380 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -3765,7 +3765,7 @@ static int vnc_display_get_address(const char *addrst= r, =20 addr->type =3D SOCKET_ADDRESS_TYPE_INET; inet =3D &addr->u.inet; - if (addrstr[0] =3D=3D '[' && addrstr[hostlen - 1] =3D=3D ']') { + if (hostlen && addrstr[0] =3D=3D '[' && addrstr[hostlen - 1] =3D= =3D ']') { inet->host =3D g_strndup(addrstr + 1, hostlen - 2); } else { inet->host =3D g_strndup(addrstr, hostlen); --=20 2.39.2