From patchwork Tue Mar 5 13:51:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roman Smirnov X-Patchwork-Id: 13582939 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 AB5D7C54798 for ; Tue, 5 Mar 2024 19:51:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9A5DE112C71; Tue, 5 Mar 2024 19:51:16 +0000 (UTC) Received: from mx01.omp.ru (mx01.omp.ru [90.154.21.10]) by gabe.freedesktop.org (Postfix) with ESMTPS id 84FDA112B0C for ; Tue, 5 Mar 2024 13:52:59 +0000 (UTC) Received: from localhost.localdomain (78.37.41.175) by msexch01.omp.ru (10.188.4.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.1258.12; Tue, 5 Mar 2024 16:52:48 +0300 From: Roman Smirnov To: Daniel Vetter , Helge Deller CC: Roman Smirnov , Thomas Zimmermann , Sergey Shtylyov , Karina Yankevich , , , , Subject: [PATCH v2] fbmon: prevent division by zero in fb_videomode_from_videomode() Date: Tue, 5 Mar 2024 16:51:50 +0300 Message-ID: <20240305135150.23240-1-r.smirnov@omp.ru> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Originating-IP: [78.37.41.175] X-ClientProxiedBy: msexch01.omp.ru (10.188.4.12) To msexch01.omp.ru (10.188.4.12) X-KSE-ServerInfo: msexch01.omp.ru, 9 X-KSE-AntiSpam-Interceptor-Info: scan successful X-KSE-AntiSpam-Version: 6.1.0, Database issued on: 03/05/2024 13:15:25 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 59 X-KSE-AntiSpam-Info: Lua profiles 183964 [Mar 05 2024] X-KSE-AntiSpam-Info: Version: 6.1.0.3 X-KSE-AntiSpam-Info: Envelope from: r.smirnov@omp.ru X-KSE-AntiSpam-Info: LuaCore: 8 0.3.8 4a99897b35b48c45ee5c877607d26a2d9f419920 X-KSE-AntiSpam-Info: {rep_avail} X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: {relay has no DNS name} X-KSE-AntiSpam-Info: {SMTP from is not routable} X-KSE-AntiSpam-Info: {Found in DNSBL: 78.37.41.175 in (user) dbl.spamhaus.org} X-KSE-AntiSpam-Info: omp.ru:7.1.1; d41d8cd98f00b204e9800998ecf8427e.com:7.1.1; 127.0.0.199:7.1.2 X-KSE-AntiSpam-Info: ApMailHostAddress: 78.37.41.175 X-KSE-AntiSpam-Info: {DNS response errors} X-KSE-AntiSpam-Info: Rate: 59 X-KSE-AntiSpam-Info: Status: not_detected X-KSE-AntiSpam-Info: Method: none X-KSE-AntiSpam-Info: Auth:dmarc=temperror header.from=omp.ru;spf=temperror smtp.mailfrom=omp.ru;dkim=none X-KSE-Antiphishing-Info: Clean X-KSE-Antiphishing-ScanningType: Heuristic X-KSE-Antiphishing-Method: None X-KSE-Antiphishing-Bases: 03/05/2024 13:20:00 X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 3/5/2024 11:10:00 AM X-KSE-Attachment-Filter-Triggered-Rules: Clean X-KSE-Attachment-Filter-Triggered-Filters: Clean X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit X-Mailman-Approved-At: Tue, 05 Mar 2024 19:51:15 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The expression htotal * vtotal can have a zero value on overflow. It is necessary to prevent division by zero like in fb_var_to_videomode(). Found by Linux Verification Center (linuxtesting.org) with Svace. Signed-off-by: Roman Smirnov Reviewed-by: Sergey Shtylyov --- V1 -> V2: Replaced the code of the first version with a check. drivers/video/fbdev/core/fbmon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/core/fbmon.c b/drivers/video/fbdev/core/fbmon.c index 79e5bfbdd34c..b137590386da 100644 --- a/drivers/video/fbdev/core/fbmon.c +++ b/drivers/video/fbdev/core/fbmon.c @@ -1344,7 +1344,7 @@ int fb_videomode_from_videomode(const struct videomode *vm, vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch + vm->vsync_len; /* prevent division by zero */ - if (htotal && vtotal) { + if (htotal && vtotal && (vm->pixelclock / htotal >= vtotal)) { fbmode->refresh = vm->pixelclock / (htotal * vtotal); /* a mode must have htotal and vtotal != 0 or it is invalid */ } else {