Return-Path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:54682 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752129AbeEGNBJ (ORCPT ); Mon, 7 May 2018 09:01:09 -0400 From: Scott Mayhew To: bfields@fieldses.org, jlayton@kernel.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH] nfsd: restrict rd_maxcount to svc_max_payload in nfsd_encode_readdir Date: Mon, 7 May 2018 09:01:08 -0400 Message-Id: <20180507130108.7136-1-smayhew@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: nfsd4_readdir_rsize restricts rd_maxcount to svc_max_payload when estimating the size of the readdir reply, but nfsd_encode_readdir restricts it to INT_MAX when encoding the reply. This can result in log messages like "kernel: RPC request reserved 32896 but used 1049444". Restrict rd_dircount similarly (no reason it should be larger than svc_max_payload). Signen-off-by: Scott Mayhew --- fs/nfsd/nfs4xdr.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 1d048dd..cfe535c 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3651,7 +3651,8 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4 nfserr = nfserr_resource; goto err_no_verf; } - maxcount = min_t(u32, readdir->rd_maxcount, INT_MAX); + maxcount = svc_max_payload(resp->rqstp); + maxcount = min_t(u32, readdir->rd_maxcount, maxcount); /* * Note the rfc defines rd_maxcount as the size of the * READDIR4resok structure, which includes the verifier above @@ -3665,7 +3666,7 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4 /* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */ if (!readdir->rd_dircount) - readdir->rd_dircount = INT_MAX; + readdir->rd_dircount = svc_max_payload(resp->rqstp); readdir->xdr = xdr; readdir->rd_maxcount = maxcount; -- 2.9.5