From patchwork Mon Apr 5 08:54:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 415744 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 B63FFC43611 for ; Mon, 5 Apr 2021 09:05:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91208613A0 for ; Mon, 5 Apr 2021 09:05:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238628AbhDEJFr (ORCPT ); Mon, 5 Apr 2021 05:05:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:49980 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238654AbhDEJFp (ORCPT ); Mon, 5 Apr 2021 05:05:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 58CF6613A7; Mon, 5 Apr 2021 09:05:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617613538; bh=pEzju/dlC2eXW2eScCWdr+GsuWS3ibxQw6GHftvlrlE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ha4py1siEOtxHPbxh+1U+SjabVrSqrbm2L6686Do7xo8t7aWGaxsr6EciPProsdEk EQqs9BQY3DMEqGiuJc87nwch+7sHHtNlru6q8gxLiSyFF8GCWZa2sCW4ApAb580NRE SuNQ9sIN+pgsPZbTdz/5uLmDDmirPaGdm4W4rCho= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com, Du Cheng Subject: [PATCH 5.4 74/74] drivers: video: fbcon: fix NULL dereference in fbcon_cursor() Date: Mon, 5 Apr 2021 10:54:38 +0200 Message-Id: <20210405085027.153874789@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210405085024.703004126@linuxfoundation.org> References: <20210405085024.703004126@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Du Cheng commit 01faae5193d6190b7b3aa93dae43f514e866d652 upstream. add null-check on function pointer before dereference on ops->cursor Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com Cc: stable Signed-off-by: Du Cheng Link: https://lore.kernel.org/r/20210312081421.452405-1-ducheng2@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/core/fbcon.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -1339,6 +1339,9 @@ static void fbcon_cursor(struct vc_data ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1; + if (!ops->cursor) + return; + ops->cursor(vc, info, mode, get_color(vc, info, c, 1), get_color(vc, info, c, 0)); }