From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6A9F7C44521 for ; Fri, 17 Jul 2026 11:54:11 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wkh8c-0004gD-U3; Fri, 17 Jul 2026 07:53:54 -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 1wkh8b-0004bA-3P for qemu-devel@nongnu.org; Fri, 17 Jul 2026 07:53:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wkh8Z-0003Rn-JP for qemu-devel@nongnu.org; Fri, 17 Jul 2026 07:53:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1784289228; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HTpzX+M6eo5BMfGMYdfxPXrnNBGT5NtLbqGrbPxJzHs=; b=h+UQbkiVr1LCBy9ZTaZdTexBIxvWAqZGzUIqGfLNwbpNpT+jH2D8TZBmDJEtFc6iQnyngc YxL080o9z/E5vkS//hPqc57ycvwaNnOiXa2SOf7h7iORzPy2l93oKKx/WJqnXYxGu4ol0P Fsf9GGyODneiA+xPp0MV7S1iU12MtTY= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-12-tlmDR1YJN46gvEF_PMjSgA-1; Fri, 17 Jul 2026 07:53:47 -0400 X-MC-Unique: tlmDR1YJN46gvEF_PMjSgA-1 X-Mimecast-MFC-AGG-ID: tlmDR1YJN46gvEF_PMjSgA_1784289226 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6546C1954B27 for ; Fri, 17 Jul 2026 11:53:46 +0000 (UTC) Received: from localhost (unknown [10.44.22.17]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 52E211956049 for ; Fri, 17 Jul 2026 11:53:44 +0000 (UTC) From: =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Date: Fri, 17 Jul 2026 15:52:47 +0400 Subject: [GIT PULL 08/15] ui/vnc: validate SetPixelFormat field ranges MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260717-fix-v1-8-cb9f7d49dc52@redhat.com> References: <20260717-fix-v1-0-cb9f7d49dc52@redhat.com> In-Reply-To: <20260717-fix-v1-0-cb9f7d49dc52@redhat.com> To: qemu-devel@nongnu.org X-Developer-Signature: v=1; a=openpgp-sha256; l=1306; i=marcandre.lureau@redhat.com; h=from:subject:message-id; bh=FG5CL8eAqS0Q4JiU5TvJg/DwgxeKGJI/nGnE2BmZm+o=; b=owEBbQKS/ZANAwAKAdro4Ql1lpzlAcsmYgBqWheaA4CzmtI7edy5sVYIdkpLCvV9uXxtiPq3n tcnWSs1xWOJAjMEAAEKAB0WIQSHqb2TP4fGBtJ29i3a6OEJdZac5QUCaloXmgAKCRDa6OEJdZac 5TrQD/wMFpp9DEifohnXpmLGd8xg7Pl56Ny4JicmO6tK9TMrR75GV9ZNe7RVcvSyPVqbFaybW3O tk2W7FGdt7fZyMEA+ot8FWlDJ/dQeNUf5a51ZIgUK5dwNAoqYXwGjLzukUejJtO8p6zzzYZAGp3 DM9uxWgsLP8iz3MLHd/pyEPtJOkhF0Zp7kTJytus/bDdH3NDb4HxVexe0ZP/4TiVtSn4KSa8BzL ORP8y+SLGxA4kz0xE9l4YLCY4LkMC1Lf3/OmmAXWu9wT3OC8OpUpfuOAknjMrHzUXFqzSNCWCSr 1qK0KniLAEe6l8zfHX1ll34D7kKhrD8bJ6TE3N6V4ldMnef1fQmhspxjXHiPx++efhjEdQvgJ4H Af3rTxMo6aeSoISRx7QEvlDfQqvID3d25X2DNVNHiuutcB9/engI0L25oc29kJeZBtWVtwnx1lW r0lSEDaqcBiYE9NGTMnpMqB/1bPlxXM5Uj9G/w5PFaSkS8emVOBU4wzjsX1FJGMSExWkItsIH9k QJ8DwtrDNzXdKWcTCeVs/W9A8l3ueryzXo2yJ/d+nYr2cYOyTiyh4vSsstAYxRzIN5vRIUFjc7r 3RqHb9fkFDLVdluQMTEHa0XIrR4RebMc7CiL8qzltzuvtAawmX0Tw30WskCNkuBch+wjur4AD0l X51qZCzgK7cJlnA== X-Developer-Key: i=marcandre.lureau@redhat.com; a=openpgp; fpr=87A9BD933F87C606D276F62DDAE8E10975969CE5 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: permerror client-ip=170.10.133.124; envelope-from=marcandre.lureau@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, T_SPF_PERMERROR=0.01 autolearn=no 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org The VNC SetPixelFormat message carries red/green/blue_max as 16-bit values, but PixelFormat stores them as uint8_t. A client sending a max value above 255 (e.g. 0x0100) passes the existing non-zero check but silently truncates to 0 on assignment, leading to a division by zero in the Tight PNG palette path. Add explicit range checks if any channel max exceeds UINT8_MAX. Fixes: CVE-2026-15578 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3976 Reported-by: dong ling Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Daniel P. Berrangé Signed-off-by: Marc-Andre Lureau --- ui/vnc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/ui/vnc.c b/ui/vnc.c index c957731877f..24aa40f7308 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -2271,6 +2271,11 @@ static void set_pixel_format(VncState *vs, uint8_t bits_per_pixel, return; } + if (red_max > UINT8_MAX || green_max > UINT8_MAX || blue_max > UINT8_MAX) { + vnc_client_error(vs); + return; + } + if (red_shift >= bits_per_pixel || red_shift >= 32 || green_shift >= bits_per_pixel || green_shift >= 32 || blue_shift >= bits_per_pixel || blue_shift >= 32) { -- 2.55.0