Commit 43c2e885 authored by J. Bruce Fields's avatar J. Bruce Fields Committed by Trond Myklebust

nfs4: fix channel attribute sanity-checks

The sanity checks here are incorrect; in the worst case they allow
values that crash the client.

They're also over-reliant on the preprocessor.
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 1c787096
......@@ -4842,49 +4842,56 @@ 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)
static int nfs4_verify_fore_channel_attrs(struct nfs41_create_session_args *args, struct nfs4_session *session)
{
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;
struct nfs4_channel_attrs *sent = &args->fc_attrs;
struct nfs4_channel_attrs *rcvd = &session->fc_attrs;
if (rcvd->headerpadsz > sent->headerpadsz)
return -EINVAL;
if (rcvd->max_resp_sz > sent->max_resp_sz)
return -EINVAL;
/*
* Our requested max_ops is the minimum we need; we're not
* prepared to break up compounds into smaller pieces than that.
* So, no point even trying to continue if the server won't
* cooperate:
*/
if (rcvd->max_ops < sent->max_ops)
return -EINVAL;
if (rcvd->max_reqs == 0)
return -EINVAL;
return 0;
}
#define _verify_fore_channel_attr(_name_) \
_verify_channel_attr("fore", #_name_, \
args->fc_attrs._name_, \
session->fc_attrs._name_)
static int nfs4_verify_back_channel_attrs(struct nfs41_create_session_args *args, struct nfs4_session *session)
{
struct nfs4_channel_attrs *sent = &args->bc_attrs;
struct nfs4_channel_attrs *rcvd = &session->bc_attrs;
#define _verify_back_channel_attr(_name_) \
_verify_channel_attr("back", #_name_, \
args->bc_attrs._name_, \
session->bc_attrs._name_)
if (rcvd->max_rqst_sz > sent->max_rqst_sz)
return -EINVAL;
if (rcvd->max_resp_sz < sent->max_resp_sz)
return -EINVAL;
if (rcvd->max_resp_sz_cached > sent->max_resp_sz_cached)
return -EINVAL;
/* These would render the backchannel useless: */
if (rcvd->max_ops == 0)
return -EINVAL;
if (rcvd->max_reqs == 0)
return -EINVAL;
return 0;
}
/*
* 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);
int ret;
return ret;
ret = nfs4_verify_fore_channel_attrs(args, session);
if (ret)
return ret;
return nfs4_verify_back_channel_attrs(args, session);
}
static int _nfs4_proc_create_session(struct nfs_client *clp)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment