From patchwork Fri Oct 30 10:23:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Chen X-Patchwork-Id: 316518 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AA7BC4363A for ; Fri, 30 Oct 2020 10:26:15 +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 175C520825 for ; Fri, 30 Oct 2020 10:26:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 175C520825 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38332 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kYRbp-0006tc-U3 for qemu-devel@archiver.kernel.org; Fri, 30 Oct 2020 06:26:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47242) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kYRZ7-0004ck-Ji; Fri, 30 Oct 2020 06:23:25 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:2490) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kYRZ5-0008Ij-QN; Fri, 30 Oct 2020 06:23:25 -0400 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4CMz0p4ByJzhd3m; Fri, 30 Oct 2020 18:23:22 +0800 (CST) Received: from [10.174.187.138] (10.174.187.138) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.487.0; Fri, 30 Oct 2020 18:23:15 +0800 Message-ID: <5F9BE993.4050406@huawei.com> Date: Fri, 30 Oct 2020 18:23:15 +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: Subject: [PATCH] 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 06:22:50 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@nongnu.org, qemu-arm@nongnu.org, QEMU Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" In omap_lcd_interrupts(), the pointer omap_lcd is dereferenced 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. Reported-by: Euler Robot Signed-off-by: Alex Chen --- hw/display/omap_lcdc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/display/omap_lcdc.c b/hw/display/omap_lcdc.c index fa4a381db6..2941c5c67c 100644 --- a/hw/display/omap_lcdc.c +++ b/hw/display/omap_lcdc.c @@ -78,7 +78,7 @@ 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; @@ -89,6 +89,7 @@ static void omap_update_display(void *opaque) return; } + surface = qemu_console_surface(omap_lcd->con); frame_offset = 0; if (omap_lcd->plm != 2) { cpu_physical_memory_read(