From patchwork Mon Feb 11 16:25:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 10806269 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C8BEF13B5 for ; Mon, 11 Feb 2019 16:25:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B780529B69 for ; Mon, 11 Feb 2019 16:25:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AC2FA2A541; Mon, 11 Feb 2019 16:25:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3536C29B69 for ; Mon, 11 Feb 2019 16:25:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728639AbfBKQZM (ORCPT ); Mon, 11 Feb 2019 11:25:12 -0500 Received: from mail-it1-f171.google.com ([209.85.166.171]:37719 "EHLO mail-it1-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728538AbfBKQZM (ORCPT ); Mon, 11 Feb 2019 11:25:12 -0500 Received: by mail-it1-f171.google.com with SMTP id b5so27668301iti.2; Mon, 11 Feb 2019 08:25:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:from:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=9kMKCrJ/Wheah38Npntkcn5b8Uj40xkO03LYa7PNCFQ=; b=Esm3WnbdwmTrSk47l3fb0wU3g+U0CapKyd+SsQt3zUxQs/n9zzh6GYZKcHYKtbSF3s aGf6n9BRcI+WTXClo3mHoBPXzNatPD8QDi8QVChoO18a3hx3lfccIn8V/loSKLxrZDN5 YYX0dlj8ndCXqpoIu8wJGZzIxOTPeyDnd+PaeUecQlQFQ86V7T7D9uZDznh4V5OFmKmb Zn1PKku47ONs2msnoAtiAm/TfYQYLzgeO1Kryb2sDyZyVChNuajd8EUD+888Y1tOmHeh awL5mMhdLMA8dLoLLiac0OCyv3Pxb0TiOuBQCBglHZUqNxS/FYoe7NQY9f6JJRJu25Nb z5LQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:from:to:cc:date:message-id :in-reply-to:references:user-agent:mime-version :content-transfer-encoding; bh=9kMKCrJ/Wheah38Npntkcn5b8Uj40xkO03LYa7PNCFQ=; b=QoyBgBZ5jclFSYr3V8IBbPiQJC+g8vKwmLK2/Q8ZGqK3vfCJaaGsFLGgmAGVfPmIpV 9ZRnAi75Bgl7w5Vpzr/CTd8InQ2zQgdP4D28GG8DzhqJThI5FPwtmhU7Vz5iZNuwFq9p 4zHZqPgygsjcXZjBXiWmt9at2P0ZOJ9ijRWOPLNdM58k16SDck1DziMihLQyuNJ2l54j BYcAZyvsmo8RGi42sH43uYv5BX6Io+yVy5KiYhwR6j9va3BfQ4LNvQhBw8NZ4hLD+fPv ktJHan8W7OgdzDAx49FCc6grIOmAwGlAIs8DPoKM/LIuqxyTZTlSRuhqBlZRQLMQsTXp MXGQ== X-Gm-Message-State: AHQUAua7fqtc8zHiemiKoZzNhzJ430kpNgLoROY5I9hYzjHgwo89bJAi gnshdoL46LAtdk9XHwA84To= X-Google-Smtp-Source: AHgI3IZ2KnTtDwhyJjusRHuBGCiyNByIR5N2z7nYJXTKLsT+XBtxm7CSib+M21xMV6eori0IWTpvgA== X-Received: by 2002:a24:89:: with SMTP id 131mr157534ita.105.1549902311153; Mon, 11 Feb 2019 08:25:11 -0800 (PST) Received: from gateway.1015granger.net (c-68-61-232-219.hsd1.mi.comcast.net. [68.61.232.219]) by smtp.gmail.com with ESMTPSA id 70sm5372156ity.9.2019.02.11.08.25.10 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 08:25:10 -0800 (PST) Received: from manet.1015granger.net (manet.1015granger.net [192.168.1.51]) by gateway.1015granger.net (8.14.7/8.14.7) with ESMTP id x1BGP9qw030003; Mon, 11 Feb 2019 16:25:09 GMT Subject: [PATCH v1 17/23] SUNRPC: Remove xdr_buf_trim() From: Chuck Lever To: anna.schumaker@netapp.com Cc: linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Date: Mon, 11 Feb 2019 11:25:09 -0500 Message-ID: <20190211162509.2817.29966.stgit@manet.1015granger.net> In-Reply-To: <20190211161920.2817.20881.stgit@manet.1015granger.net> References: <20190211161920.2817.20881.stgit@manet.1015granger.net> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The key action of xdr_buf_trim() is that it shortens buf->len, the length of the xdr_buf's content. The other actions -- shortening the head, pages, and tail components -- are actually not necessary. In particular, changing the size of those components can corrupt the RPC message contained in the buffer. This is an accident waiting to happen rather than a current bug, as far as we know. Signed-off-by: Chuck Lever Acked-by: Bruce Fields --- include/linux/sunrpc/xdr.h | 1 - net/sunrpc/auth_gss/gss_krb5_wrap.c | 8 ++++--- net/sunrpc/auth_gss/svcauth_gss.c | 2 +- net/sunrpc/xdr.c | 41 ----------------------------------- 4 files changed, 6 insertions(+), 46 deletions(-) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 65af6a2..9ee3970 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -179,7 +179,6 @@ static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int le extern void xdr_shift_buf(struct xdr_buf *, size_t); extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *); extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int); -extern void xdr_buf_trim(struct xdr_buf *, unsigned int); extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int); extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int); diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c index 5cdde6c..14a0aff 100644 --- a/net/sunrpc/auth_gss/gss_krb5_wrap.c +++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c @@ -570,14 +570,16 @@ static void rotate_left(u32 base, struct xdr_buf *buf, unsigned int shift) */ movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len); movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip; - BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen > - buf->head[0].iov_len); + if (offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen > + buf->head[0].iov_len) + return GSS_S_FAILURE; memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen); buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip; buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip; /* Trim off the trailing "extra count" and checksum blob */ - xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip); + buf->len -= ec + GSS_KRB5_TOK_HDR_LEN + tailskip; + return GSS_S_COMPLETE; } diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index 152790e..f1aabab 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -896,7 +896,7 @@ u32 svcauth_gss_flavor(struct auth_domain *dom) if (svc_getnl(&buf->head[0]) != seq) goto out; /* trim off the mic and padding at the end before returning */ - xdr_buf_trim(buf, round_up_to_quad(mic.len) + 4); + buf->len -= 4 + round_up_to_quad(mic.len); stat = 0; out: kfree(mic.data); diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 5f0aa53..4bce619 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -1139,47 +1139,6 @@ void xdr_enter_page(struct xdr_stream *xdr, unsigned int len) } EXPORT_SYMBOL_GPL(xdr_buf_subsegment); -/** - * xdr_buf_trim - lop at most "len" bytes off the end of "buf" - * @buf: buf to be trimmed - * @len: number of bytes to reduce "buf" by - * - * Trim an xdr_buf by the given number of bytes by fixing up the lengths. Note - * that it's possible that we'll trim less than that amount if the xdr_buf is - * too small, or if (for instance) it's all in the head and the parser has - * already read too far into it. - */ -void xdr_buf_trim(struct xdr_buf *buf, unsigned int len) -{ - size_t cur; - unsigned int trim = len; - - if (buf->tail[0].iov_len) { - cur = min_t(size_t, buf->tail[0].iov_len, trim); - buf->tail[0].iov_len -= cur; - trim -= cur; - if (!trim) - goto fix_len; - } - - if (buf->page_len) { - cur = min_t(unsigned int, buf->page_len, trim); - buf->page_len -= cur; - trim -= cur; - if (!trim) - goto fix_len; - } - - if (buf->head[0].iov_len) { - cur = min_t(size_t, buf->head[0].iov_len, trim); - buf->head[0].iov_len -= cur; - trim -= cur; - } -fix_len: - buf->len -= (len - trim); -} -EXPORT_SYMBOL_GPL(xdr_buf_trim); - static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) { unsigned int this_len;