From patchwork Sat Oct 31 03:35:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Chen X-Patchwork-Id: 1391420 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com 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 ozlabs.org (Postfix) with ESMTPS id 4CNPx54kC4z9s0b for ; Sat, 31 Oct 2020 14:36:38 +1100 (AEDT) Received: from localhost ([::1]:43134 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kYhgx-0006rm-20 for incoming@patchwork.ozlabs.org; Fri, 30 Oct 2020 23:36:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60158) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kYhgO-0006rR-Ho; Fri, 30 Oct 2020 23:36:00 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:2491) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kYhgL-00046d-Lm; Fri, 30 Oct 2020 23:36:00 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4CNPw50qLpzhcVL; Sat, 31 Oct 2020 11:35:49 +0800 (CST) Received: from [10.174.187.138] (10.174.187.138) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.487.0; Sat, 31 Oct 2020 11:35:38 +0800 Message-ID: <5F9CDB8A.9000001@huawei.com> Date: Sat, 31 Oct 2020 11:35:38 +0800 From: AlexChen User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Peter Maydell Subject: [PATCH V2] hw/display/omap_lcdc: Fix potential NULL pointer dereference X-Originating-IP: [10.174.187.138] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.191; envelope-from=alex.chen@huawei.com; helo=szxga05-in.huawei.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/30 23:35:49 X-ACL-Warn: Detected OS = Linux 3.1-3.10 [fuzzy] X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no 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: QEMU Trivial , zhengchuan@huawei.com, qemu-arm , QEMU , zhang.zhanghailiang@huawei.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" In omap_lcd_interrupts(), the pointer omap_lcd is dereferinced before being check if it is valid, which may lead to NULL pointer dereference. So move the assignment to surface after checking that the omap_lcd is valid and move surface_bits_per_pixel(surface) to after the surface assignment. Reported-by: Euler Robot Signed-off-by: AlexChen --- hw/display/omap_lcdc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/hw/display/omap_lcdc.c b/hw/display/omap_lcdc.c index fa4a381db6..58e659c94f 100644 --- a/hw/display/omap_lcdc.c +++ b/hw/display/omap_lcdc.c @@ -78,14 +78,18 @@ static void omap_lcd_interrupts(struct omap_lcd_panel_s *s) static void omap_update_display(void *opaque) { struct omap_lcd_panel_s *omap_lcd = (struct omap_lcd_panel_s *) opaque; - DisplaySurface *surface = qemu_console_surface(omap_lcd->con); + DisplaySurface *surface; draw_line_func draw_line; int size, height, first, last; int width, linesize, step, bpp, frame_offset; hwaddr frame_base; - if (!omap_lcd || omap_lcd->plm == 1 || !omap_lcd->enable || - !surface_bits_per_pixel(surface)) { + if (!omap_lcd || omap_lcd->plm == 1 || !omap_lcd->enable) { + return; + } + + surface = qemu_console_surface(omap_lcd->con); + if (!surface_bits_per_pixel(surface)) { return; }