From nobody Thu Apr 30 00:42:40 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 lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1776216322301206.11998404849828; Tue, 14 Apr 2026 18:25:22 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wCozd-0003zg-BR; Tue, 14 Apr 2026 21:24:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wCozX-0003z4-Oi for qemu-devel@nongnu.org; Tue, 14 Apr 2026 21:24:32 -0400 Received: from mailgw.kylinos.cn ([124.126.103.232]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wCozU-0007sT-TJ for qemu-devel@nongnu.org; Tue, 14 Apr 2026 21:24:31 -0400 Received: from localhost.localdomain [(116.128.244.171)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA with TLSv1.3 TLS_AES_256_GCM_SHA384 256/256) with ESMTP id 1546656504; Wed, 15 Apr 2026 09:24:09 +0800 X-UUID: cdaa65d8386911f1aa26b74ffac11d73-20260415 X-CID-O-RULE: Release_Ham X-CID-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.12, REQID:838ace5f-8f5c-4dc6-a8c8-f8f6d1ca7cc3, IP:15, URL:0,TC:0,Content:0,EDM:0,RT:0,SF:-15,FILE:0,BULK:0,RULE:Release_Ham,ACTI ON:release,TS:0 X-CID-INFO: VERSION:1.3.12, REQID:838ace5f-8f5c-4dc6-a8c8-f8f6d1ca7cc3, IP:15, UR L:0,TC:0,Content:0,EDM:0,RT:0,SF:-15,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:0 X-CID-META: VersionHash:e7bac3a, CLOUDID:a73e5dc2a6387b21f940792dbf995a6c, BulkI D:260415092410WP6HJ0RW,BulkQuantity:0,Recheck:0,SF:10|66|78|101|102|123|12 7|850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bulk:n il,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,BR E:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: cdaa65d8386911f1aa26b74ffac11d73-20260415 X-User: zhaoguohan@kylinos.cn From: zhaoguohan@kylinos.cn To: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Cc: qemu-devel@nongnu.org Subject: [PATCH] ui/vnc-clipboard: validate decompressed text length Date: Wed, 15 Apr 2026 09:23:36 +0800 Message-ID: <20260415012336.964736-1-zhaoguohan@kylinos.cn> X-Mailer: git-send-email 2.43.0 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=lists1p.gnu.org; Received-SPF: pass client-ip=124.126.103.232; envelope-from=zhaoguohan@kylinos.cn; helo=mailgw.kylinos.cn X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, UNPARSEABLE_RELAY=0.001 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: qemu development 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: 1776216326425158500 Content-Type: text/plain; charset="utf-8" From: GuoHan Zhao The decompressed clipboard data starts with a 32-bit text length. Check that the advertised length fits in the payload after that header before passing it to qemu_clipboard_set_data(). Otherwise a malformed VNC clipboard message can make QEMU read past the end of the decompressed buffer. Fixes: 0bf41cab93e5 ("ui/vnc: clipboard support") Signed-off-by: GuoHan Zhao Reviewed-by: Marc-Andr=C3=A9 Lureau --- ui/vnc-clipboard.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/ui/vnc-clipboard.c b/ui/vnc-clipboard.c index 124b6fbd9c23..85851a632dba 100644 --- a/ui/vnc-clipboard.c +++ b/ui/vnc-clipboard.c @@ -281,8 +281,8 @@ void vnc_client_cut_text_ext(VncState *vs, int32_t len,= uint32_t flags, uint8_t if ((flags & VNC_CLIPBOARD_TEXT) && buf && size >=3D 4) { uint32_t tsize =3D read_u32(buf, 0); - uint8_t *tbuf =3D buf + 4; - if (tsize < size) { + uint8_t *tbuf =3D buf + sizeof(tsize); + if (tsize <=3D size - sizeof(tsize)) { qemu_clipboard_set_data(&vs->cbpeer, vs->cbinfo, QEMU_CLIPBOARD_TYPE_TEXT, tsize, tbuf, true); --=20 2.43.0