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 55084598C08 for ; Tue, 8 Sep 2026 18:42:06 +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=1788892927; cv=none; b=YquGh6hCQ+Wh+fMrHtZvBrfHwA5sbJXlgOGvYe3B+lDlC9UJb7iqdpul3Vuv5uHg9EvtvNo/MVuOQ/oj9oCrCQ3DgBVDv56ckKs40tUeXkPF9SrOuoZpqIwQaEgccf+eXrjhMpBvkOBEq/Th5S2k9t8Fl2PEqm1nttUL/qaS1sA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788892927; c=relaxed/simple; bh=1pD7jG6iFl3jR3DgXHSESBL3NdnVeEt56el2UJCvVq8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=V84xJjimvTYykrxkt7258jBDvDy56wUUoZrjOso2LN30dDNo79KWUXOCDouwlngeBrvwdPhVs+9fekk1MLuuVsCDTjaYoY0+5fr77bm0Y/of4hu4tyEoFoUO1ahbPdKBVJ9DKvDJrvs+kShNHXNEYIMqKZAF095FPpa434qdml4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RtEcYAJQ; 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="RtEcYAJQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 712CA1F00AC4; Tue, 8 Sep 2026 18:42:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788892925; bh=1MFvz1ayQLR5s55l3F6QMMB6/z75KXzdrGRNkiyRH+Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RtEcYAJQNQtJUTWqbIYtAKuHGGfJomvmlhbO0IUJjEb65o/RkqEgmZZOUxz8Dhpvw 6iuZ+6Gf2Wn8idKHDxWnm8e9hcA99qqAXz3sO99Yz6cP2io4bVtR9wALJgR9NEd7c2 PMM8gb4wQanhPnCEagjumcVXqHq+eqATdKmKqbWGZL0Gh1eFVOK0lHUpBTWC7622nJ Qqg3QzFj4T0GCe/yN2FSfqZKD9B2wkamwouFst6aOvGXyHGxo2FFzQHYBtHXFNisaW DyHXGBh5hYs5kENkpD6O+v8idCAWcT6bQv+ShnPxXgggqjZadig7l3K1xGjYEZ4/mP bKZdVyU2t11xQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Chuck Lever , Jeff Layton , Sasha Levin Subject: [PATCH 5.10.y 3/4] SUNRPC: Convert unwrap_priv_data() to use xdr_stream Date: Tue, 8 Sep 2026 14:42:01 -0400 Message-ID: <20260908184202.249958-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260908184202.249958-1-sashal@kernel.org> References: <2026090353-ogle-atop-5025@gregkh> <20260908184202.249958-1-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 [ sashal: Reduced backport -- upstream 42140718ea26c touches 3 file(s), this backport carries 1. Not backported here: include/linux/sunrpc/xdr.h net/sunrpc/xdr.c This note is generated from the file lists only; see the resolution record for the reasoning. ] Stable-dep-of: a919c5c88769 ("SUNRPC: svcauth_gss: enforce krb5 token minimum length") Signed-off-by: Sasha Levin --- net/sunrpc/auth_gss/svcauth_gss.c | 64 ++++++++++--------------------- 1 file changed, 21 insertions(+), 43 deletions(-) diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index b9674a77b048a..78f67a0725579 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -970,17 +970,6 @@ 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 * @@ -993,49 +982,37 @@ 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; @@ -1663,8 +1640,9 @@ 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; -- 2.53.0