From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Scott Mayhew" , "J. Bruce Fields" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: Subject: [PATCH 3.16 035/366] nfsd: restrict rd_maxcount to svc_max_payload in nfsd_encode_readdir In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Scott Mayhew commit 9c2ece6ef67e9d376f32823086169b489c422ed0 upstream. 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). Signed-off-by: Scott Mayhew Signed-off-by: J. Bruce Fields Signed-off-by: Ben Hutchings --- fs/nfsd/nfs4xdr.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3343,7 +3343,8 @@ nfsd4_encode_readdir(struct nfsd4_compou 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 @@ -3357,7 +3358,7 @@ nfsd4_encode_readdir(struct nfsd4_compou /* 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;