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 lists.gnu.org (lists.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 6AE3AC433F5 for ; Mon, 14 Feb 2022 12:10:59 +0000 (UTC) Received: from localhost ([::1]:34052 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nJaC2-0006by-KA for qemu-devel@archiver.kernel.org; Mon, 14 Feb 2022 07:10:58 -0500 Received: from eggs.gnu.org ([209.51.188.92]:39840) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nJa4S-0006xG-1t for qemu-devel@nongnu.org; Mon, 14 Feb 2022 07:03:08 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:29162) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nJa4I-0006Iw-4p for qemu-devel@nongnu.org; Mon, 14 Feb 2022 07:03:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644840177; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rgqz1hoSDJpGnrmmnjqz6dgh4sZ7ORGLnMsr3ngpq8I=; b=MEi73QciQOwLHhnIOP17hPhkmf5k2dRwQTQjQOUkgTbHI8UilZ4WKSBoRosQPVUWelQC7T Z39x06jhzCHnJY03WTrhBfLeo0S2qrS/0XXM0BL0ER53UBoJcSHLYoe9zSlhZfu6MaGS36 Fk0DyFQWrJ7OQ1gdFZad5dDU/EGDycE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-459-F9zb8QX5OHKUMJtMNLcWVA-1; Mon, 14 Feb 2022 07:02:51 -0500 X-MC-Unique: F9zb8QX5OHKUMJtMNLcWVA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AE03C801B0F for ; Mon, 14 Feb 2022 12:02:50 +0000 (UTC) Received: from redhat.com (unknown [10.39.192.189]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DE3E070D24; Mon, 14 Feb 2022 12:02:07 +0000 (UTC) Date: Mon, 14 Feb 2022 12:02:05 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: marcandre.lureau@redhat.com Subject: Re: [PATCH] ui/clipboard: fix use-after-free regression Message-ID: References: <20220214115917.1679568-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 In-Reply-To: <20220214115917.1679568-1-marcandre.lureau@redhat.com> User-Agent: Mutt/2.1.5 (2021-12-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: qemu-devel@nongnu.org, kraxel@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Feb 14, 2022 at 03:59:17PM +0400, marcandre.lureau@redhat.com wrote: > From: Marc-André Lureau > > The same info may be used to update the clipboard, and may be freed > before being ref'ed again. Ewww, subtle. > Fixes: 70a54b01693ed ("ui: avoid compiler warnings from unused clipboard info variable") > > Signed-off-by: Marc-André Lureau > --- > ui/clipboard.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/ui/clipboard.c b/ui/clipboard.c > index 5f15cf853d07..9079ef829b51 100644 > --- a/ui/clipboard.c > +++ b/ui/clipboard.c > @@ -66,8 +66,10 @@ void qemu_clipboard_update(QemuClipboardInfo *info) > > notifier_list_notify(&clipboard_notifiers, ¬ify); > > - qemu_clipboard_info_unref(cbinfo[info->selection]); > - cbinfo[info->selection] = qemu_clipboard_info_ref(info); > + if (cbinfo[info->selection] != info) { > + qemu_clipboard_info_unref(cbinfo[info->selection]); > + cbinfo[info->selection] = qemu_clipboard_info_ref(info); > + } > } Reviewed-by: Daniel P. Berrangé Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|