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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 BA134C52D30 for ; Thu, 27 Feb 2020 14:07:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8ED0621D7E for ; Thu, 27 Feb 2020 14:07:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582812429; bh=jTvwhF4KjEeGmTKvwo1HGhYhl0LBnNBc2sIqXvNxEEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uJVHX8iSGw9LtY1TtAQKM1A0G7uZ6+YYru4WHlP6SLuUPQcfc1UOYYBtuwGEOrSrY uSha54TCb+724JRzhifVIvSDjRPyW1i8ezzqr2iFbeVd/kFAYa7EBsIqws+sTc6SF7 tUc55dnUzJXqtzCtzd0V+oeabKxsaQ/tF8tOw0jQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388030AbgB0OHH (ORCPT ); Thu, 27 Feb 2020 09:07:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:44382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388010AbgB0OHB (ORCPT ); Thu, 27 Feb 2020 09:07:01 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 0EBE621D7E; Thu, 27 Feb 2020 14:06:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582812420; bh=jTvwhF4KjEeGmTKvwo1HGhYhl0LBnNBc2sIqXvNxEEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PNqkjCHOb8pGvVSaAA1qdz1wQ3FXKX71mfgix0HnTUHW6SZ3QrZf1kz1GJt2/U/FQ zhOveru1ETpzmVeGugYkomH0aYDvBKYX9PnYZQMv8mn1iQL3egRgav/SGbu1obcq6e Mju7QbvWZJskooLltXj8DtjRuNMTXqZJVfqr68l8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicholas Johnson , Mika Westerberg Subject: [PATCH 5.4 011/135] thunderbolt: Prevent crash if non-active NVMem file is read Date: Thu, 27 Feb 2020 14:35:51 +0100 Message-Id: <20200227132230.736007053@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200227132228.710492098@linuxfoundation.org> References: <20200227132228.710492098@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mika Westerberg commit 03cd45d2e219301880cabc357e3cf478a500080f upstream. The driver does not populate .reg_read callback for the non-active NVMem because the file is supposed to be write-only. However, it turns out NVMem subsystem does not yet support this and expects that the .reg_read callback is provided. If user reads the binary attribute it triggers NULL pointer dereference like this one: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace: bin_attr_nvmem_read+0x64/0x80 kernfs_fop_read+0xa7/0x180 vfs_read+0xbd/0x170 ksys_read+0x5a/0xd0 do_syscall_64+0x43/0x150 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix this in the driver by providing .reg_read callback that always returns an error. Reported-by: Nicholas Johnson Fixes: e6b245ccd524 ("thunderbolt: Add support for host and device NVM firmware upgrade") Signed-off-by: Mika Westerberg Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200213095604.1074-1-mika.westerberg@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/thunderbolt/switch.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -274,6 +274,12 @@ out: return ret; } +static int tb_switch_nvm_no_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + return -EPERM; +} + static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val, size_t bytes) { @@ -319,6 +325,7 @@ static struct nvmem_device *register_nvm config.read_only = true; } else { config.name = "nvm_non_active"; + config.reg_read = tb_switch_nvm_no_read; config.reg_write = tb_switch_nvm_write; config.root_only = true; }