From patchwork Wed Jun 3 18:55:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 11586149 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A50F61391 for ; Wed, 3 Jun 2020 18:58:23 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 3B30F2077D for ; Wed, 3 Jun 2020 18:58:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="jK2Dhxfv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B30F2077D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:41304 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jgYak-0006tF-5q for patchwork-qemu-devel@patchwork.kernel.org; Wed, 03 Jun 2020 14:58:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33346) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jgYa4-000679-G8 for qemu-devel@nongnu.org; Wed, 03 Jun 2020 14:57:40 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:48515 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jgYa2-0001bS-TF for qemu-devel@nongnu.org; Wed, 03 Jun 2020 14:57:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591210657; h=from:from: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; bh=GrlBf7nmYTAXVG5xBhh2XusfIat7d/Qooh/R76PHWFU=; b=jK2DhxfvbNa05wpjOzxp4SNiKk8o6lZmIGmoCFuEDZk7CxdbctF1iUwynOfwsCHxKIOJwb +r2xvwVWK+XoahOg603Uy13CNevYHmThKoiR21rBtS7Al4mZirbfzpav6v/AGfA1/pYt8a W/O/l0Hdq7ZXlpyvbm5jbqSr0bWHKKA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-185-NfuagYcmNJeL7l8d225rPw-1; Wed, 03 Jun 2020 14:57:33 -0400 X-MC-Unique: NfuagYcmNJeL7l8d225rPw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 64A3618A0762; Wed, 3 Jun 2020 18:57:32 +0000 (UTC) Received: from localhost.localdomain (unknown [10.74.8.119]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F28465C297; Wed, 3 Jun 2020 18:57:25 +0000 (UTC) From: P J P To: Gerd Hoffmann Subject: [PATCH v2] ati-vga: check mm_index before recursive call Date: Thu, 4 Jun 2020 00:25:22 +0530 Message-Id: <20200603185522.1173354-1-ppandit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.81; envelope-from=ppandit@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/03 01:12:11 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Prasad J Pandit , Yi Ren , QEMU Developers , Ren Ding , Hanqing Zhao Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" From: Prasad J Pandit While accessing VGA registers via ati_mm_read/write routines, a guest may set 's->regs.mm_index' such that it leads to infinite recursion. Check mm_index value to avoid it. Reported-by: Ren Ding Reported-by: Hanqing Zhao Reported-by: Yi Ren Signed-off-by: Prasad J Pandit --- hw/display/ati.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Update v2: add check before recursive call -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00781.html diff --git a/hw/display/ati.c b/hw/display/ati.c index 065f197678..bda4a2d816 100644 --- a/hw/display/ati.c +++ b/hw/display/ati.c @@ -285,7 +285,7 @@ static uint64_t ati_mm_read(void *opaque, hwaddr addr, unsigned int size) if (idx <= s->vga.vram_size - size) { val = ldn_le_p(s->vga.vram_ptr + idx, size); } - } else { + } else if (s->regs.mm_index > MM_DATA + 3) { val = ati_mm_read(s, s->regs.mm_index + addr - MM_DATA, size); } break; @@ -520,7 +520,7 @@ static void ati_mm_write(void *opaque, hwaddr addr, if (idx <= s->vga.vram_size - size) { stn_le_p(s->vga.vram_ptr + idx, size, data); } - } else { + } else if (s->regs.mm_index > MM_DATA + 3) { ati_mm_write(s, s->regs.mm_index + addr - MM_DATA, data, size); } break;