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,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 6D5F9C43603 for ; Wed, 11 Dec 2019 15:11:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C2D122B48 for ; Wed, 11 Dec 2019 15:11:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576077065; bh=bMEM8CgX/6uIErmN9B5ttGlNi4wBwVVcAmuXfFf4Z8U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qXDERyM5N1tK9UYexLkjN7DoV0afLtdVxQ1s5vO9P4oSHLoxLXGix9QncVs6jDyrD iTST+gqGZpbnEy3odPtk+RePZNeY9PHqea5m9CnHe4Ci54bqRRzp8B1/0Qyz5nx8mb a6/zjOMG8/Yz18RZ2YEU8J4QqraL85tZdJaNZD8U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730237AbfLKPLD (ORCPT ); Wed, 11 Dec 2019 10:11:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:59482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730862AbfLKPLB (ORCPT ); Wed, 11 Dec 2019 10:11:01 -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 D2DE124656; Wed, 11 Dec 2019 15:11:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576077061; bh=bMEM8CgX/6uIErmN9B5ttGlNi4wBwVVcAmuXfFf4Z8U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zR38MCXqQRVg8vMJ0vx3RJB8EYorFw7AVeg9JexgvLwNLKf3vEEhANg6ZLjBH0guI dYqqs/0Xd/bnOTsoxF6PR9Cnnv+OM3x/zZ5JvoWKdg9gBG+Ke3QW+zfm5hSca1dcW6 Fqm1jYq3LV749v5s8qGJnDJLePX9Tt/eWQk1gR8o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Viresh Kumar , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.4 82/92] RDMA/qib: Validate ->show()/store() callbacks before calling them Date: Wed, 11 Dec 2019 16:06:13 +0100 Message-Id: <20191211150300.723842793@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191211150221.977775294@linuxfoundation.org> References: <20191211150221.977775294@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: Viresh Kumar commit 7ee23491b39259ae83899dd93b2a29ef0f22f0a7 upstream. The permissions of the read-only or write-only sysfs files can be changed (as root) and the user can then try to read a write-only file or write to a read-only file which will lead to kernel crash here. Protect against that by always validating the show/store callbacks. Link: https://lore.kernel.org/r/d45cc26361a174ae12dbb86c994ef334d257924b.1573096807.git.viresh.kumar@linaro.org Signed-off-by: Viresh Kumar Reviewed-by: Greg Kroah-Hartman Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/hw/qib/qib_sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/infiniband/hw/qib/qib_sysfs.c +++ b/drivers/infiniband/hw/qib/qib_sysfs.c @@ -301,6 +301,9 @@ static ssize_t qib_portattr_show(struct struct qib_pportdata *ppd = container_of(kobj, struct qib_pportdata, pport_kobj); + if (!pattr->show) + return -EIO; + return pattr->show(ppd, buf); } @@ -312,6 +315,9 @@ static ssize_t qib_portattr_store(struct struct qib_pportdata *ppd = container_of(kobj, struct qib_pportdata, pport_kobj); + if (!pattr->store) + return -EIO; + return pattr->store(ppd, buf, len); }