From: Andy Adamson <andros@xxxxxxxxxx>
Invalidate the session if the server returns invalid fore or back channel
attributes.
Use a KERN_WARNING to report the fatal session estabishment error.
Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
[refactor nfs4_verify_channel_attrs]
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 4381939..5ce8999 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4412,6 +4412,51 @@ static void nfs4_init_channel_attrs(struct nfs41_create_session_args *args)
args->bc_attrs.max_reqs);
}
+static int _verify_channel_attr(char *chan, char *attr_name, u32 sent, u32 rcvd)
+{
+ if (rcvd <= sent)
+ return 0;
+ printk(KERN_WARNING "%s: Session INVALID: %s channel %s increased. "
+ "sent=%u rcvd=%u\n", __func__, chan, attr_name, sent, rcvd);
+ return -EINVAL;
+}
+
+#define _verify_fore_channel_attr(_name_) \
+ _verify_channel_attr("fore", #_name_, \
+ args->fc_attrs._name_, \
+ session->fc_attrs._name_)
+
+#define _verify_back_channel_attr(_name_) \
+ _verify_channel_attr("back", #_name_, \
+ args->bc_attrs._name_, \
+ session->bc_attrs._name_)
+
+/*
+ * The server is not allowed to increase the fore channel header pad size,
+ * maximum response size, or maximum number of operations.
+ *
+ * The back channel attributes are only negotiatied down: We send what the
+ * (back channel) server insists upon.
+ */
+static int nfs4_verify_channel_attrs(struct nfs41_create_session_args *args,
+ struct nfs4_session *session)
+{
+ int ret = 0;
+
+ ret |= _verify_fore_channel_attr(headerpadsz);
+ ret |= _verify_fore_channel_attr(max_resp_sz);
+ ret |= _verify_fore_channel_attr(max_ops);
+
+ ret |= _verify_back_channel_attr(headerpadsz);
+ ret |= _verify_back_channel_attr(max_rqst_sz);
+ ret |= _verify_back_channel_attr(max_resp_sz);
+ ret |= _verify_back_channel_attr(max_resp_sz_cached);
+ ret |= _verify_back_channel_attr(max_ops);
+ ret |= _verify_back_channel_attr(max_reqs);
+
+ return ret;
+}
+
static int _nfs4_proc_create_session(struct nfs_client *clp)
{
struct nfs4_session *session = clp->cl_session;
@@ -4434,8 +4479,9 @@ static int _nfs4_proc_create_session(struct nfs_client *clp)
status = rpc_call_sync(session->clp->cl_rpcclient, &msg, 0);
- /* Set the negotiated values in the session's channel_attrs struct */
-
+ if (!status)
+ /* Verify the session's negotiated channel_attrs values */
+ status = nfs4_verify_channel_attrs(&args, session);
if (!status) {
/* Increment the clientid slot sequence id */
clp->cl_seqid++;
--
1.6.2.1
--
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