From patchwork Tue Oct 27 13:49:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 290204 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 0935AC55178 for ; Tue, 27 Oct 2020 13:58:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5B5F218AC for ; Tue, 27 Oct 2020 13:58:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603807097; bh=JZO0FMmtG4vn/Ir8BKBtAao/jx/uemYfhrNZ6ukyQ5c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lC+Hv6FqZXCBtJKiM7opj7ZZJxQZLqLJCv/s5HcC4aIyH5PeWoCctMhmrfZIe9AM+ gTUN+RmNqW3q9wK8+44PbGrZL7IuJWjm4FP0clhZhi0WXRTIG6cvoRFzVLAOOqgWrH yjmJZ3EV2gqSe9c7jZi1Og/VR+U6R/3IHDGokeCg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2504001AbgJ0N6Q (ORCPT ); Tue, 27 Oct 2020 09:58:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:45468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753044AbgJ0N6P (ORCPT ); Tue, 27 Oct 2020 09:58:15 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2A452206D4; Tue, 27 Oct 2020 13:58:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603807094; bh=JZO0FMmtG4vn/Ir8BKBtAao/jx/uemYfhrNZ6ukyQ5c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bfsAN6ijlyRcLdthg2N1FIf5oJgd2Na22Z2LY2s+gQmHrvOBmz2hVRPcafZoITFbe mhSEsV3iMeeYj2plXBH9oSR9j7DTCPwxM+IGVErzDbjwd3+1fQOnAkY9FnALvBfkMn SU5SKYUyxh2VRFm7aJBNO9qeoCYHLkRzJ488zwy8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tom Rix , Thomas Winischhofer , Andrew Morton , Bartlomiej Zolnierkiewicz , Sasha Levin Subject: [PATCH 4.4 041/112] video: fbdev: sis: fix null ptr dereference Date: Tue, 27 Oct 2020 14:49:11 +0100 Message-Id: <20201027134902.500435453@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027134900.532249571@linuxfoundation.org> References: <20201027134900.532249571@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tom Rix [ Upstream commit ad6f93e9cd56f0b10e9b22e3e137d17a1a035242 ] Clang static analysis reports this representative error init.c:2501:18: warning: Array access (from variable 'queuedata') results in a null pointer dereference templ |= ((queuedata[i] & 0xc0) << 3); This is the problem block of code if(ModeNo > 0x13) { ... if(SiS_Pr->ChipType == SIS_730) { queuedata = &FQBQData730[0]; } else { queuedata = &FQBQData[0]; } } else { } queuedata is not set in the else block Reviewing the old code, the arrays FQBQData730 and FQBQData were used directly. So hoist the setting of queuedata out of the if-else block. Fixes: 544393fe584d ("[PATCH] sisfb update") Signed-off-by: Tom Rix Cc: Thomas Winischhofer Cc: Andrew Morton Signed-off-by: Bartlomiej Zolnierkiewicz Link: https://patchwork.freedesktop.org/patch/msgid/20200805145208.17727-1-trix@redhat.com Signed-off-by: Sasha Levin --- drivers/video/fbdev/sis/init.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/video/fbdev/sis/init.c b/drivers/video/fbdev/sis/init.c index dfe3eb769638b..fde27feae5d0c 100644 --- a/drivers/video/fbdev/sis/init.c +++ b/drivers/video/fbdev/sis/init.c @@ -2428,6 +2428,11 @@ SiS_SetCRT1FIFO_630(struct SiS_Private *SiS_Pr, unsigned short ModeNo, i = 0; + if (SiS_Pr->ChipType == SIS_730) + queuedata = &FQBQData730[0]; + else + queuedata = &FQBQData[0]; + if(ModeNo > 0x13) { /* Get VCLK */ @@ -2445,12 +2450,6 @@ SiS_SetCRT1FIFO_630(struct SiS_Private *SiS_Pr, unsigned short ModeNo, /* Get half colordepth */ colorth = colortharray[(SiS_Pr->SiS_ModeType - ModeEGA)]; - if(SiS_Pr->ChipType == SIS_730) { - queuedata = &FQBQData730[0]; - } else { - queuedata = &FQBQData[0]; - } - do { templ = SiS_CalcDelay2(SiS_Pr, queuedata[i]) * VCLK * colorth;