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| author | J. Bruce Fields <bfields@redhat.com> | 2017-11-15 20:30:27 +0300 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2018-02-08 21:40:16 +0300 |
| commit | 0078117c6d9160031b866cfa1853514d4f6865d2 (patch) | |
| tree | 284b86e03244fca4e73f872fb32c42e08987590c | |
| parent | 2502072058b35e2297f4ad7b211a45ad95a6a3d5 (diff) | |
| download | linux-0078117c6d9160031b866cfa1853514d4f6865d2.tar.xz | |
nfsd: return RESOURCE not GARBAGE_ARGS on too many ops
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>
| -rw-r--r-- | fs/nfsd/nfs4proc.c | 3 | ||||
| -rw-r--r-- | 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 effeeb4f556f..a0bed2b2004d 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1703,6 +1703,9 @@ 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 2c61c6b8ae09..5dcd7cb45b2d 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1918,8 +1918,13 @@ 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); |