From patchwork Thu Jun 30 20:48:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12902216 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6226CC433EF for ; Thu, 30 Jun 2022 20:48:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230148AbiF3UsW (ORCPT ); Thu, 30 Jun 2022 16:48:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229838AbiF3UsV (ORCPT ); Thu, 30 Jun 2022 16:48:21 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C90961835C for ; Thu, 30 Jun 2022 13:48:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6E30462358 for ; Thu, 30 Jun 2022 20:48:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83134C34115; Thu, 30 Jun 2022 20:48:19 +0000 (UTC) Subject: [PATCH v2] SUNRPC: Fix READ_PLUS crasher From: Chuck Lever To: linux-nfs@vger.kernel.org Cc: anna.schumaker@netapp.com, bfields@fieldses.org, zlang@redhat.com Date: Thu, 30 Jun 2022 16:48:18 -0400 Message-ID: <165662209842.1459.4593520026847863736.stgit@klimt.1015granger.net> User-Agent: StGit/1.5.dev3+g9561319 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Looks like there are still cases when "space_left - frag1bytes" can legitimately exceed PAGE_SIZE. Ensure that xdr->end always remains within the current encode buffer. Reported-by: Bruce Fields Reported-by: Zorro Lang Link: https://bugzilla.kernel.org/show_bug.cgi?id=216151 Fixes: 6c254bf3b637 ("SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer()") Signed-off-by: Chuck Lever --- net/sunrpc/xdr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index f87a2d8f23a7..5d2b3e6979fb 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -984,7 +984,7 @@ static noinline __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, p = page_address(*xdr->page_ptr); xdr->p = p + frag2bytes; space_left = xdr->buf->buflen - xdr->buf->len; - if (space_left - nbytes >= PAGE_SIZE) + if (space_left - frag1bytes >= PAGE_SIZE) xdr->end = p + PAGE_SIZE; else xdr->end = p + space_left - frag1bytes;