From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EDD861774C for ; Wed, 9 Aug 2023 11:11:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 733EBC433C8; Wed, 9 Aug 2023 11:11:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691579494; bh=xvhHhuxrHpLzUkuLVxv4BvM0EUUxnl962J8jqrP9NIA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U8J+wKVuaaKFlOm1jaOGnHkmIf/VuF9wGoe58NbN2FgHFjH1Uwh22I3KuoaFHlsTN qy7muYz2JKpJKgDxYTZLoGAVsM28zNAnTg9SIg+yla26GRioZnj1dnSChw/rKk1ftM 8NSK/uLYzMrtndoaTqX3dUWOCVAofWWZujjjF+YA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zheng Wang , Helge Deller Subject: [PATCH 4.19 004/323] fbdev: imsttfb: Fix use after free bug in imsttfb_probe Date: Wed, 9 Aug 2023 12:37:22 +0200 Message-ID: <20230809103658.309437457@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103658.104386911@linuxfoundation.org> References: <20230809103658.104386911@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Zheng Wang commit c75f5a55061091030a13fef71b9995b89bc86213 upstream. 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: Greg Kroah-Hartman --- drivers/video/fbdev/imsttfb.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/drivers/video/fbdev/imsttfb.c +++ b/drivers/video/fbdev/imsttfb.c @@ -1348,7 +1348,7 @@ static 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 *i || !(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 *i 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) @@ -1527,10 +1528,10 @@ static int imsttfb_probe(struct pci_dev 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)