From patchwork Mon Apr 4 08:47:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheyu Ma X-Patchwork-Id: 12800006 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8ADBC433EF for ; Mon, 4 Apr 2022 08:48:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241779AbiDDIt7 (ORCPT ); Mon, 4 Apr 2022 04:49:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241883AbiDDItq (ORCPT ); Mon, 4 Apr 2022 04:49:46 -0400 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2AFA93BA5F; Mon, 4 Apr 2022 01:47:51 -0700 (PDT) Received: by mail-pl1-x629.google.com with SMTP id o10so1663154ple.7; Mon, 04 Apr 2022 01:47:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=6lQXVT/uUsnfVE8WcNYNQC83df5wSK/7H6QlhzyGSpQ=; b=KHLiQpb41/Jw+rhklJELDpaMOhckeHIcsw9AtQfrQZVhXUpiSvQOoEqLOWnWZt5N1z fvw5nL32fYw19ijPqYbuxD1CKpEfwJ5AWt/SVteFr4bVvwv6VdXylzhAcHNAJ2DDNUoD uJYWZuWDo3vo/IlAuNirkKPlaCiPaYIxYxkT6R1KdmrLjESBZ8q1NViVRwLfWSDjIaJ1 zHy5Alslrx8QGBPFt4DtgHTz7U+DYAGT0DlpOpDG4CIRSZnMFJxfQ1HxmLAHtuNWexeX KsPVNi1JlUl1f0C3+1/nq7L4cfl9ib7E3+w4a5wLnn86lSz0M+PNAdC0Jm3TUXKx2Yc3 IyYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=6lQXVT/uUsnfVE8WcNYNQC83df5wSK/7H6QlhzyGSpQ=; b=4q1Pj6gP3mQJAmitA3+OVSu8pkvIAYXQv3mRT9gSdrO7sOTOV6XuojrLW8mkHL3/UZ SKXj8it6iHnMV3tSZ6FIMQehDDbYKKQA9l/tNDv504I3l41wRX7Ddzfay4oYVzVpZz3Z RvFRjmSqayWUYhhAVmWXKUjuFs6yMcr9KcsMZNPHjzdHgAsqiJk79U7ECkFUgkt/ky49 nMeR8jd1UkzJhZjZKFRHFcFJOi5YKSHi3slztLZCcBz9fSXaygzXpN1jaj1CVXYJ4Z62 G0kjav7U0RxF0IJ094+Hy/Cfewm/VsOTAgjm/duqH9EOk+jDB34ZFlrRJrYIBtY38uZI 9QKg== X-Gm-Message-State: AOAM532KeJwK1H12LxHiv99s2Y2GAXc/cjqOICd/0tPw0cIZ1Ey5Vjcb CcZuYiI9MyRET2mRMKkZzw== X-Google-Smtp-Source: ABdhPJz4d1wgPvWQSKcf0Ti+XkoQbDjoaZEPj5OUoHAmUr4JUgtLaBghkz4cZl6tbHh/c+SMdrjEVQ== X-Received: by 2002:a17:902:7887:b0:156:788a:56d1 with SMTP id q7-20020a170902788700b00156788a56d1mr10208376pll.110.1649062070526; Mon, 04 Apr 2022 01:47:50 -0700 (PDT) Received: from localhost.localdomain ([144.202.91.207]) by smtp.gmail.com with ESMTPSA id u6-20020a17090a3fc600b001ca88b0bdfesm3991960pjm.13.2022.04.04.01.47.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Apr 2022 01:47:50 -0700 (PDT) From: Zheyu Ma To: deller@gmx.de Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Zheyu Ma Subject: [PATCH 2/7] video: fbdev: neofb: Fix the check of 'var->pixclock' Date: Mon, 4 Apr 2022 16:47:18 +0800 Message-Id: <20220404084723.79089-3-zheyuma97@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220404084723.79089-1-zheyuma97@gmail.com> References: <20220404084723.79089-1-zheyuma97@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org The previous check against 'var->pixclock' doesn't return -EINVAL when it equals zero, but the driver uses it again, causing the divide error. Fix this by returning when 'var->pixclock' is zero. The following log reveals it: [ 49.704574] divide error: 0000 [#1] PREEMPT SMP KASAN PTI [ 49.704593] RIP: 0010:neofb_set_par+0x190f/0x49a0 [ 49.704635] Call Trace: [ 49.704636] [ 49.704650] fb_set_var+0x604/0xeb0 [ 49.704702] do_fb_ioctl+0x234/0x670 [ 49.704745] fb_ioctl+0xdd/0x130 [ 49.704753] do_syscall_64+0x3b/0x90 Signed-off-by: Zheyu Ma --- drivers/video/fbdev/neofb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/neofb.c b/drivers/video/fbdev/neofb.c index 966df2a07360..28d32cbf496b 100644 --- a/drivers/video/fbdev/neofb.c +++ b/drivers/video/fbdev/neofb.c @@ -585,7 +585,7 @@ neofb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) DBG("neofb_check_var"); - if (var->pixclock && PICOS2KHZ(var->pixclock) > par->maxClock) + if (!var->pixclock || PICOS2KHZ(var->pixclock) > par->maxClock) return -EINVAL; /* Is the mode larger than the LCD panel? */