From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7AAEE59B67D for ; Tue, 8 Sep 2026 18:04:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788890679; cv=none; b=PZbx4h34y7CbnLnbXS/Yw/WTD0xOjw1TMygiGA02bf6ujUaE62Q8tuzsFsjSw3DwsO6VtFped71Ruh6sjjJMqotlGYaalNhO6GCanjiOg46QYRk7RJptVjDsxvmXJqw60tfPmT6o0AEzQ+s0Sd8LWAbAsOVZDhCpSs0jSn70Sh8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788890679; c=relaxed/simple; bh=wVvs4E9HX98Sl5B09C25FbQXwpBG2tPk0mvAws1UweE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BHjwkh1d4bQEdk3QV3/sAoXyk1Qu7AAnIsVFMcv+hNZid+D4Msanbc+yRZ3bAgquA/VGt+XioD3GP8H8jAatnbPcJ4jnP89ENZoGzNWDktpcfdE10hPHpp9MY9Y0zpAH6CKRlcWVvr3h2Hd9Xn7PVmfg/AvErgDAQkdZM9AojG8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jCfDOW2n; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jCfDOW2n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C1161F00AC4; Tue, 8 Sep 2026 18:04:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788890675; bh=RSW1TCNNtNkOlVVvugdeXs71oOCX3tEK1vQZba8Qf48=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jCfDOW2nveOjTRv7WH39vGbhgRceIxyy49OmEJr8qVQsyH3yUVtGZWr8LS14uevRw UqeHEewOQ/TpWLvlaFMOml3eAe8FwMCuBcxVMjLss3q/ezDTgKCWGhXwgnfy3di1ZS 78+eqNPdaWIsP3ltnBwm/3tZmqO/9izP1yYjAPzWxjRs6Yrg03vSciSm55ClFjxXM1 /4D2gKhlf6qQN08tPVTac6iqLjlejQHEMfpzj1l7/oVnfFesmVjDNq024gmcKTbpf2 mjyCqusaa/FZmTGL57Ywveq+9/BpD4rj9NVS+eW9Q59swtjiQfW9DTDWoCbeQ2ImY2 NgcWk2P2n9Bbg== From: Sasha Levin To: stable@vger.kernel.org Cc: Chuck Lever , Jeff Layton , Sasha Levin Subject: [PATCH 5.15.y 3/4] SUNRPC: Convert unwrap_priv_data() to use xdr_stream Date: Tue, 8 Sep 2026 14:04:31 -0400 Message-ID: <20260908180432.174786-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260908180432.174786-1-sashal@kernel.org> References: <2026090352-bamboo-relic-6231@gregkh> <20260908180432.174786-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Chuck Lever [ Upstream commit 42140718ea26c47fb06c679451a6aa6703545136 ] Done as part of hardening the server-side RPC header decoding path. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Stable-dep-of: a919c5c88769 ("SUNRPC: svcauth_gss: enforce krb5 token minimum length") Signed-off-by: Sasha Levin --- include/linux/sunrpc/xdr.h | 1 - net/sunrpc/auth_gss/svcauth_gss.c | 64 ++++++++++--------------------- net/sunrpc/xdr.c | 7 ---- 3 files changed, 21 insertions(+), 51 deletions(-) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 98e197376a0d9..add7174cb245a 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -188,7 +188,6 @@ xdr_adjust_iovec(struct kvec *iov, __be32 *p) /* * XDR buffer helper functions */ -extern void xdr_shift_buf(struct xdr_buf *, size_t); extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *); extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int); extern void xdr_buf_trim(struct xdr_buf *, unsigned int); diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index 7ba523335aefa..afcfdb2f84b6c 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -972,17 +972,6 @@ total_buf_len(struct xdr_buf *buf) return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len; } -static void -fix_priv_head(struct xdr_buf *buf, int pad) -{ - if (buf->page_len == 0) { - /* We need to adjust head and buf->len in tandem in this - * case to make svc_defer() work--it finds the original - * buffer start using buf->len - buf->head[0].iov_len. */ - buf->head[0].iov_len -= pad; - } -} - /* * RFC 2203, Section 5.3.2.3 * @@ -995,49 +984,37 @@ fix_priv_head(struct xdr_buf *buf, int pad) * proc_req_arg_t arg; * }; */ -static int -svcauth_gss_unwrap_priv(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, - struct gss_ctx *ctx) +static noinline_for_stack int +svcauth_gss_unwrap_priv(struct svc_rqst *rqstp, u32 seq, struct gss_ctx *ctx) { - u32 len, seq_num, maj_stat; - int pad, remaining_len, offset; + struct xdr_stream *xdr = &rqstp->rq_arg_stream; + u32 len, maj_stat, seq_num, offset; + struct xdr_buf *buf = xdr->buf; + unsigned int saved_len; clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); - len = svc_getnl(&buf->head[0]); + if (xdr_stream_decode_u32(xdr, &len) < 0) + goto unwrap_failed; if (rqstp->rq_deferred) { /* Already decrypted last time through! The sequence number * check at out_seq is unnecessary but harmless: */ goto out_seq; } - /* buf->len is the number of bytes from the original start of the - * request to the end, where head[0].iov_len is just the bytes - * not yet read from the head, so these two values are different: */ - remaining_len = total_buf_len(buf); - if (len > remaining_len) + if (len > xdr_stream_remaining(xdr)) goto unwrap_failed; - pad = remaining_len - len; - buf->len -= pad; - fix_priv_head(buf, pad); - - maj_stat = gss_unwrap(ctx, 0, len, buf); - pad = len - buf->len; - /* The upper layers assume the buffer is aligned on 4-byte boundaries. - * In the krb5p case, at least, the data ends up offset, so we need to - * move it around. */ - /* XXX: This is very inefficient. It would be better to either do - * this while we encrypt, or maybe in the receive code, if we can peak - * ahead and work out the service and mechanism there. */ - offset = xdr_pad_size(buf->head[0].iov_len); - if (offset) { - buf->buflen = RPCSVC_MAXPAYLOAD; - xdr_shift_buf(buf, offset); - fix_priv_head(buf, pad); - } + offset = xdr_stream_pos(xdr); + + saved_len = buf->len; + maj_stat = gss_unwrap(ctx, offset, offset + len, buf); if (maj_stat != GSS_S_COMPLETE) goto bad_unwrap; + xdr->nwords -= XDR_QUADLEN(saved_len - buf->len); + out_seq: - seq_num = svc_getnl(&buf->head[0]); + /* gss_unwrap() decrypted the sequence number. */ + if (xdr_stream_decode_u32(xdr, &seq_num) < 0) + goto unwrap_failed; if (seq_num != seq) goto bad_seqno; return 0; @@ -1665,8 +1642,9 @@ svcauth_gss_accept(struct svc_rqst *rqstp) /* placeholders for length and seq. number: */ svc_putnl(resv, 0); svc_putnl(resv, 0); - if (svcauth_gss_unwrap_priv(rqstp, &rqstp->rq_arg, - gc->gc_seq, rsci->mechctx)) + svcxdr_init_decode(rqstp); + if (svcauth_gss_unwrap_priv(rqstp, gc->gc_seq, + rsci->mechctx)) goto garbage_args; rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE * 2; break; diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index b227d0c8471ff..34cd38e757d6f 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -835,13 +835,6 @@ static unsigned int xdr_shrink_pagelen(struct xdr_buf *buf, unsigned int len) return shift; } -void -xdr_shift_buf(struct xdr_buf *buf, size_t len) -{ - xdr_shrink_bufhead(buf, buf->head->iov_len - len); -} -EXPORT_SYMBOL_GPL(xdr_shift_buf); - /** * xdr_stream_pos - Return the current offset from the start of the xdr_stream * @xdr: pointer to struct xdr_stream -- 2.53.0