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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 D2AADC677D4 for ; Mon, 8 Oct 2018 18:37:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C82E2064A for ; Mon, 8 Oct 2018 18:37:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="bGc51NiF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C82E2064A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728761AbeJIBuF (ORCPT ); Mon, 8 Oct 2018 21:50:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:35766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726529AbeJIBuE (ORCPT ); Mon, 8 Oct 2018 21:50:04 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (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 A78182064A; Mon, 8 Oct 2018 18:37:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539023821; bh=cd6SnLS71X+bV/7Q7NiLeo/Xqa8kQlyaobnOlwBdOFs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bGc51NiF03seqaowGXzjzxySU7xTt4gbUymMoZi+EiES6nEoXKp6YoC3JGCxIMsH2 XwFBedBhCm/Br7wSceLTwvlYaAaYCPe8rrLVNze5W3/4K8DaLmYDIuCs/BsuxfxAr8 eoHnGakSodEaYpf8GV3gU/WHaNt95XwNbrsIUHO0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jann Horn , Jason Gunthorpe , Sasha Levin Subject: [PATCH 4.4 095/113] RDMA/ucma: check fd type in ucma_migrate_id() Date: Mon, 8 Oct 2018 20:31:36 +0200 Message-Id: <20181008175536.500248706@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181008175530.864641368@linuxfoundation.org> References: <20181008175530.864641368@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jann Horn [ Upstream commit 0d23ba6034b9cf48b8918404367506da3e4b3ee5 ] The current code grabs the private_data of whatever file descriptor userspace has supplied and implicitly casts it to a `struct ucma_file *`, potentially causing a type confusion. This is probably fine in practice because the pointer is only used for comparisons, it is never actually dereferenced; and even in the comparisons, it is unlikely that a file from another filesystem would have a ->private_data pointer that happens to also be valid in this context. But ->private_data is not always guaranteed to be a valid pointer to an object owned by the file's filesystem; for example, some filesystems just cram numbers in there. Check the type of the supplied file descriptor to be safe, analogous to how other places in the kernel do it. Fixes: 88314e4dda1e ("RDMA/cma: add support for rdma_migrate_id()") Signed-off-by: Jann Horn Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/ucma.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -123,6 +123,8 @@ static DEFINE_MUTEX(mut); static DEFINE_IDR(ctx_idr); static DEFINE_IDR(multicast_idr); +static const struct file_operations ucma_fops; + static inline struct ucma_context *_ucma_find_context(int id, struct ucma_file *file) { @@ -1535,6 +1537,10 @@ static ssize_t ucma_migrate_id(struct uc f = fdget(cmd.fd); if (!f.file) return -ENOENT; + if (f.file->f_op != &ucma_fops) { + ret = -EINVAL; + goto file_put; + } /* Validate current fd and prevent destruction of id. */ ctx = ucma_get_ctx(f.file->private_data, cmd.id);