nfsd: return RESOURCE not GARBAGE_ARGS on too many ops
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Web: https://git.kernel.org/torvalds/c/0078117c6d9160031b866cfa1853514d4f6865d2 Commit: 0078117c6d9160031b866cfa1853514d4f6865d2 Parent: 2502072058b35e2297f4ad7b211a45ad95a6a3d5 Refname: refs/heads/master Author: J. Bruce Fields <[email protected]> AuthorDate: Wed Nov 15 12:30:27 2017 -0500 Committer: J. Bruce Fields <[email protected]> CommitDate: Thu Feb 8 13:40:16 2018 -0500 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" <[email protected]> Signed-off-by: J. Bruce Fields <[email protected]> --- 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 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); -- To unsubscribe from this list: send the line "unsubscribe git-commits-head" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html