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 924BFC4167B for ; Thu, 14 Apr 2022 14:21:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349542AbiDNOUl (ORCPT ); Thu, 14 Apr 2022 10:20:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343936AbiDNNjb (ORCPT ); Thu, 14 Apr 2022 09:39:31 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DDCB9D4DF; Thu, 14 Apr 2022 06:35:34 -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 ams.source.kernel.org (Postfix) with ESMTPS id DEB5EB82983; Thu, 14 Apr 2022 13:35:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A0CDC385A5; Thu, 14 Apr 2022 13:35:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649943331; bh=U5DXGMZkZO7Pn/O1SPamsvQIw3Rc+QzrCc82s4iJ0ZM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ftINMlf7c1O9wmcDnunPkElkB9O9qyMcED9hUviJ9Whu9Xq0em8Cl0Iq8A24Iqp4G p1F1HkNd3xuk7mJqnpcC6M0nYahA48Qkq9/nfWOfqdXCJ1KfY3FFCpNEHZjtNFWLGu RvmSJRAXlyBbyBWgNjghHaJC60Z2WccQva2ncVeE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hulk Robot , Wang Hai , Thomas Zimmermann , Helge Deller , Sasha Levin Subject: [PATCH 5.4 117/475] video: fbdev: smscufx: Fix null-ptr-deref in ufx_usb_probe() Date: Thu, 14 Apr 2022 15:08:22 +0200 Message-Id: <20220414110858.426272826@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110855.141582785@linuxfoundation.org> References: <20220414110855.141582785@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wang Hai [ Upstream commit 1791f487f877a9e83d81c8677bd3e7b259e7cb27 ] I got a null-ptr-deref report: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... RIP: 0010:fb_destroy_modelist+0x38/0x100 ... Call Trace: ufx_usb_probe.cold+0x2b5/0xac1 [smscufx] usb_probe_interface+0x1aa/0x3c0 [usbcore] really_probe+0x167/0x460 ... ret_from_fork+0x1f/0x30 If fb_alloc_cmap() fails in ufx_usb_probe(), fb_destroy_modelist() will be called to destroy modelist in the error handling path. But modelist has not been initialized yet, so it will result in null-ptr-deref. Initialize modelist before calling fb_alloc_cmap() to fix this bug. Fixes: 3c8a63e22a08 ("Add support for SMSC UFX6000/7000 USB display adapters") Reported-by: Hulk Robot Signed-off-by: Wang Hai Acked-by: Thomas Zimmermann Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- drivers/video/fbdev/smscufx.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/video/fbdev/smscufx.c b/drivers/video/fbdev/smscufx.c index 0e0f5bbfc5ef..ad60f739c6a1 100644 --- a/drivers/video/fbdev/smscufx.c +++ b/drivers/video/fbdev/smscufx.c @@ -1657,6 +1657,7 @@ static int ufx_usb_probe(struct usb_interface *interface, info->par = dev; info->pseudo_palette = dev->pseudo_palette; info->fbops = &ufx_ops; + INIT_LIST_HEAD(&info->modelist); retval = fb_alloc_cmap(&info->cmap, 256, 0); if (retval < 0) { @@ -1667,8 +1668,6 @@ static int ufx_usb_probe(struct usb_interface *interface, INIT_DELAYED_WORK(&dev->free_framebuffer_work, ufx_free_framebuffer_work); - INIT_LIST_HEAD(&info->modelist); - retval = ufx_reg_read(dev, 0x3000, &id_rev); check_warn_goto_error(retval, "error %d reading 0x3000 register from device", retval); dev_dbg(dev->gdev, "ID_REV register value 0x%08x", id_rev); -- 2.34.1