From: "J. Bruce Fields" bfields@redhat.com
[ Upstream commit 0078117c6d9160031b866cfa1853514d4f6865d2 ]
A client that sends more than a hundred ops in a single compound currently gets an rpc-level GARBAGE_ARGS error.
It would be more helpful to return NFS4ERR_RESOURCE, since that gives the client a better idea how to recover (for example by splitting up the compound into smaller compounds).
This is all a bit academic since we've never actually seen a reason for clients to send such long compounds, but we may as well fix it.
While we're there, just use NFSD4_MAX_OPS_PER_COMPOUND == 16, the constant we already use in the 4.1 case, instead of hard-coding 100. Chances anyone actually uses even 16 ops per compound are small enough that I think there's a neglible risk or any regression.
This fixes pynfs test COMP6.
Reported-by: "Lu, Xinyu" luxy.fnst@cn.fujitsu.com Signed-off-by: J. Bruce Fields bfields@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- fs/nfsd/nfs4proc.c | 3 +++ fs/nfsd/nfs4xdr.c | 9 +++++++-- 2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index f6429b3d89e2..a976c87eae49 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1342,6 +1342,9 @@ nfsd4_proc_compound(struct svc_rqst *rqstp, status = nfserr_minor_vers_mismatch; if (nfsd_minorversion(args->minorversion, NFSD_TEST) <= 0) goto out; + status = nfserr_resource; + if (args->opcnt > NFSD_MAX_OPS_PER_COMPOUND) + goto out;
status = nfs41_check_op_ordering(args); if (status) { diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 660c813467e2..c8ebd89f0f2d 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1655,8 +1655,13 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
if (argp->taglen > NFSD4_MAX_TAGLEN) goto xdr_error; - if (argp->opcnt > 100) - goto xdr_error; + /* + * NFS4ERR_RESOURCE is a more helpful error than GARBAGE_ARGS + * here, so we return success at the xdr level so that + * nfsd4_proc can handle this is an NFS-level error. + */ + if (argp->opcnt > NFSD_MAX_OPS_PER_COMPOUND) + return 0;
if (argp->opcnt > ARRAY_SIZE(argp->iops)) { argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);