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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 A2696C433E0 for ; Mon, 29 Jun 2020 18:56:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B30F204EC for ; Mon, 29 Jun 2020 18:56:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593456962; bh=C6FW2g4U3g9zleI+T6QiaWuTQjwS7KiK2AgAFaLs56w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qMCxWDkqMUaywWhGTVFOp3mWKyNmq1ZjH1prHs3o2dDbrxoUgotrJVyvsR1h6uPsL r1OOsmZ3cOwmlI2tDn4+JC64VmWUnBnLi31uPPc6ezEq71WXMWXEZ2hk8xkUy7aOnz TP7d6gQtbkKUmGGseBBZKbppN909m3/8OvxTIIgk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728559AbgF2S4B (ORCPT ); Mon, 29 Jun 2020 14:56:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:42464 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729975AbgF2SzR (ORCPT ); Mon, 29 Jun 2020 14:55:17 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EE93C25579; Mon, 29 Jun 2020 15:55:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593446142; bh=C6FW2g4U3g9zleI+T6QiaWuTQjwS7KiK2AgAFaLs56w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ng6HIQjcOEABxj12/uEgXMyLzxV8uqN0gez9wffQ1T3D0VOf3A8suWCkbGfgdV5Xs Ie5eIlxNPTY8lvxLjqyfLdJG6Ci7ZlnUei8AK18oC4NIhDckjl04UTSHHcJSDCKlOA 7+Yl+01rQvgc1wOMo4Re4e9B2zjHAuKSB/RolAvg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Chuck Lever , Anna Schumaker , Greg Kroah-Hartman Subject: [PATCH 4.4 130/135] SUNRPC: Properly set the @subbuf parameter of xdr_buf_subsegment() Date: Mon, 29 Jun 2020 11:53:04 -0400 Message-Id: <20200629155309.2495516-131-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629155309.2495516-1-sashal@kernel.org> References: <20200629155309.2495516-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.4.229-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.4.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.4.229-rc1 X-KernelTest-Deadline: 2020-07-01T15:53+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chuck Lever commit 89a3c9f5b9f0bcaa9aea3e8b2a616fcaea9aad78 upstream. @subbuf is an output parameter of xdr_buf_subsegment(). A survey of call sites shows that @subbuf is always uninitialized before xdr_buf_segment() is invoked by callers. There are some execution paths through xdr_buf_subsegment() that do not set all of the fields in @subbuf, leaving some pointer fields containing garbage addresses. Subsequent processing of that buffer then results in a page fault. Signed-off-by: Chuck Lever Cc: Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/xdr.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index ed9bbd383f7d3..df7ecf9584f68 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1031,6 +1031,7 @@ xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, base = 0; } else { base -= buf->head[0].iov_len; + subbuf->head[0].iov_base = buf->head[0].iov_base; subbuf->head[0].iov_len = 0; } @@ -1043,6 +1044,8 @@ xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, base = 0; } else { base -= buf->page_len; + subbuf->pages = buf->pages; + subbuf->page_base = 0; subbuf->page_len = 0; } @@ -1054,6 +1057,7 @@ xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, base = 0; } else { base -= buf->tail[0].iov_len; + subbuf->tail[0].iov_base = buf->tail[0].iov_base; subbuf->tail[0].iov_len = 0; } -- 2.25.1