From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
We can simplify session limit enforcement by restricting the xdr buflen
to the session size.
Also fix a preexisting bug: we should really have been taking into
account the auth-required space when comparing against session limits,
which are limits on the size of the entire rpc reply, including any krb5
overhead.
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 11 +++++++++++
fs/nfsd/nfs4xdr.c | 24 ++++++++----------------
2 files changed, 19 insertions(+), 16 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e936d9f..09be2e0 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2208,11 +2208,13 @@ nfsd4_sequence(struct svc_rqst *rqstp,
struct nfsd4_sequence *seq)
{
struct nfsd4_compoundres *resp = rqstp->rq_resp;
+ struct xdr_stream *xdr = &resp->xdr;
struct nfsd4_session *session;
struct nfs4_client *clp;
struct nfsd4_slot *slot;
struct nfsd4_conn *conn;
__be32 status;
+ int buflen;
struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
if (resp->opcnt != 1)
@@ -2281,6 +2283,15 @@ nfsd4_sequence(struct svc_rqst *rqstp,
if (status)
goto out_put_session;
+ buflen = (seq->cachethis) ?
+ session->se_fchannel.maxresp_cached :
+ session->se_fchannel.maxresp_sz;
+ status = (seq->cachethis) ? nfserr_rep_too_big_to_cache :
+ nfserr_rep_too_big;
+ if (xdr_restrict_buflen(xdr, buflen - 2 * RPC_MAX_AUTH_SIZE))
+ goto out_put_session;
+
+ status = nfs_ok;
/* Success! bump slot seqid */
slot->sl_seqid = seq->seqid;
slot->sl_flags |= NFSD4_SLOT_INUSE;
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index ad594f2..311e281 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3767,25 +3767,17 @@ static nfsd4_enc nfsd4_enc_ops[] = {
__be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
{
struct xdr_buf *buf = &resp->rqstp->rq_res;
- struct nfsd4_session *session = resp->cstate.session;
+ struct nfsd4_slot *slot = resp->cstate.slot;
- if (nfsd4_has_session(&resp->cstate)) {
- struct nfsd4_slot *slot = resp->cstate.slot;
-
- if (buf->len + respsize > session->se_fchannel.maxresp_sz)
- return nfserr_rep_too_big;
-
- if ((slot->sl_flags & NFSD4_SLOT_CACHETHIS) &&
- buf->len + respsize > session->se_fchannel.maxresp_cached)
- return nfserr_rep_too_big_to_cache;
- }
-
- if (buf->len + respsize > buf->buflen) {
- WARN_ON_ONCE(nfsd4_has_session(&resp->cstate));
+ if (buf->len + respsize <= buf->buflen)
+ return nfs_ok;
+ if (!nfsd4_has_session(&resp->cstate))
return nfserr_resource;
+ if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
+ WARN_ON_ONCE(1);
+ return nfserr_rep_too_big_to_cache;
}
-
- return 0;
+ return nfserr_rep_too_big;
}
void
--
1.9.0
--
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