From mboxrd@z Thu Jan 1 00:00:00 1970 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 D52ACC77B7D for ; Sat, 20 May 2023 18:20:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231559AbjETSUo (ORCPT ); Sat, 20 May 2023 14:20:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231881AbjETSUc (ORCPT ); Sat, 20 May 2023 14:20:32 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6770B10F7; Sat, 20 May 2023 11:20:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5DE7860AF2; Sat, 20 May 2023 18:20:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D15C0C433EF; Sat, 20 May 2023 18:20:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684606806; bh=t0DvZ7heiAOR2gaainKo1OXYll/0QkH8RC6nJ4z0lZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Pci/UCT8aON4pSgnl7LmQTGvS5kexnq4Xahi31hFET00tazFqwt1Ezfj3D7TNCubP M4JU2qq88g6UInIxiJkGTNeR82/9YzqmZEz8jdSB383ybDpVuG2d7kXxSaRedjVQQc aWnxBG+QJXr45ADfRj5+bs4+OWpOFUtPVPjrsEzv3RHyVijjZt7//OdbFFysZcz+I3 6oIVPOW34xOg3+n+R07IqNqIjyBznwhfOEIv9lEXjiGnbG7vi4R39FQ1dIKVJ98xUS XqGdtzyoJkVIyIWZWM22xvJlqLvsgAlMUIF5Uk8RWH5hnJ2Yckxd2sv7DM9LFh7z3p 3JouE1n+s9Kyw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zheng Wang , Helge Deller , Sasha Levin , tzimmermann@suse.de, javierm@redhat.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.3 14/18] fbdev: imsttfb: Fix use after free bug in imsttfb_probe Date: Sat, 20 May 2023 14:17:46 -0400 Message-Id: <20230520181750.823365-14-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230520181750.823365-1-sashal@kernel.org> References: <20230520181750.823365-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org From: Zheng Wang [ Upstream commit c75f5a55061091030a13fef71b9995b89bc86213 ] A use-after-free bug may occur if init_imstt invokes framebuffer_release and free the info ptr. The caller, imsttfb_probe didn't notice that and still keep the ptr as private data in pdev. If we remove the driver which will call imsttfb_remove to make cleanup, UAF happens. Fix it by return error code if bad case happens in init_imstt. Signed-off-by: Zheng Wang Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- drivers/video/fbdev/imsttfb.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c index bea45647184e1..975dd682fae4b 100644 --- a/drivers/video/fbdev/imsttfb.c +++ b/drivers/video/fbdev/imsttfb.c @@ -1347,7 +1347,7 @@ static const struct fb_ops imsttfb_ops = { .fb_ioctl = imsttfb_ioctl, }; -static void init_imstt(struct fb_info *info) +static int init_imstt(struct fb_info *info) { struct imstt_par *par = info->par; __u32 i, tmp, *ip, *end; @@ -1420,7 +1420,7 @@ static void init_imstt(struct fb_info *info) || !(compute_imstt_regvals(par, info->var.xres, info->var.yres))) { printk("imsttfb: %ux%ux%u not supported\n", info->var.xres, info->var.yres, info->var.bits_per_pixel); framebuffer_release(info); - return; + return -ENODEV; } sprintf(info->fix.id, "IMS TT (%s)", par->ramdac == IBM ? "IBM" : "TVP"); @@ -1456,12 +1456,13 @@ static void init_imstt(struct fb_info *info) if (register_framebuffer(info) < 0) { framebuffer_release(info); - return; + return -ENODEV; } tmp = (read_reg_le32(par->dc_regs, SSTATUS) & 0x0f00) >> 8; fb_info(info, "%s frame buffer; %uMB vram; chip version %u\n", info->fix.id, info->fix.smem_len >> 20, tmp); + return 0; } static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent) @@ -1529,10 +1530,10 @@ static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent) if (!par->cmap_regs) goto error; info->pseudo_palette = par->palette; - init_imstt(info); - - pci_set_drvdata(pdev, info); - return 0; + ret = init_imstt(info); + if (!ret) + pci_set_drvdata(pdev, info); + return ret; error: if (par->dc_regs) -- 2.39.2