From: Scott Mayhew <smayhew@redhat.com>
Date: Mon, 7 May 2018 09:01:08 -0400
Subject: [PATCH] nfsd: restrict rd_maxcount to svc_max_payload in
nfsd_encode_readdir
Git-commit: 9c2ece6ef67e9d376f32823086169b489c422ed0
Patch-mainline: v4.18
References: git-fixes
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 <smayhew@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>
---
fs/nfsd/nfs4xdr.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3673,7 +3673,8 @@ 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
@@ -3687,7 +3688,7 @@ 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;