SUNRPC handle EKEYEXPIRED in call_refreshresult

Currently, when an RPCSEC_GSS context has expired or is non-existent
and the users (Kerberos) credentials have also expired or are non-existent,
the client receives the -EKEYEXPIRED error and tries to refresh the context
forever.  If an application is performing I/O, or other work against the share,
the application hangs, and the user is not prompted to refresh/establish their
credentials. This can result in a denial of service for other users.

Users are expected to manage their Kerberos credential lifetimes to mitigate
this issue.

Move the -EKEYEXPIRED handling into the RPC layer. Try tk_cred_retry number
of times to refresh the gss_context, and then return -EACCES to the application.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Andy Adamson 2012-11-27 10:34:19 -05:00 committed by Trond Myklebust
parent 620038f6d2
commit eb96d5c97b
6 changed files with 4 additions and 88 deletions

View File

@ -24,14 +24,14 @@
#define NFSDBG_FACILITY NFSDBG_PROC
/* A wrapper to handle the EJUKEBOX and EKEYEXPIRED error messages */
/* A wrapper to handle the EJUKEBOX error messages */
static int
nfs3_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
{
int res;
do {
res = rpc_call_sync(clnt, msg, flags);
if (res != -EJUKEBOX && res != -EKEYEXPIRED)
if (res != -EJUKEBOX)
break;
freezable_schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
res = -ERESTARTSYS;
@ -44,7 +44,7 @@ nfs3_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
static int
nfs3_async_handle_jukebox(struct rpc_task *task, struct inode *inode)
{
if (task->tk_status != -EJUKEBOX && task->tk_status != -EKEYEXPIRED)
if (task->tk_status != -EJUKEBOX)
return 0;
if (task->tk_status == -EJUKEBOX)
nfs_inc_stats(inode, NFSIOS_DELAY);

View File

@ -179,7 +179,6 @@ static int filelayout_async_handle_error(struct rpc_task *task,
break;
case -NFS4ERR_DELAY:
case -NFS4ERR_GRACE:
case -EKEYEXPIRED:
rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
break;
case -NFS4ERR_RETRY_UNCACHED_REP:

View File

@ -333,7 +333,6 @@ static int nfs4_handle_exception(struct nfs_server *server, int errorcode, struc
}
case -NFS4ERR_GRACE:
case -NFS4ERR_DELAY:
case -EKEYEXPIRED:
ret = nfs4_delay(server->client, &exception->timeout);
if (ret != 0)
break;
@ -1343,13 +1342,6 @@ int nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs4_state
nfs_inode_find_state_and_recover(state->inode,
stateid);
nfs4_schedule_stateid_recovery(server, state);
case -EKEYEXPIRED:
/*
* User RPCSEC_GSS context has expired.
* We cannot recover this stateid now, so
* skip it and allow recovery thread to
* proceed.
*/
case -ENOMEM:
err = 0;
goto out;
@ -3946,7 +3938,6 @@ nfs4_async_handle_error(struct rpc_task *task, const struct nfs_server *server,
case -NFS4ERR_DELAY:
nfs_inc_server_stats(server, NFSIOS_DELAY);
case -NFS4ERR_GRACE:
case -EKEYEXPIRED:
rpc_delay(task, NFS4_POLL_RETRY_MAX);
task->tk_status = 0;
return -EAGAIN;
@ -4946,15 +4937,6 @@ int nfs4_lock_delegation_recall(struct nfs4_state *state, struct file_lock *fl)
nfs4_schedule_stateid_recovery(server, state);
err = 0;
goto out;
case -EKEYEXPIRED:
/*
* User RPCSEC_GSS context has expired.
* We cannot recover this stateid now, so
* skip it and allow recovery thread to
* proceed.
*/
err = 0;
goto out;
case -ENOMEM:
case -NFS4ERR_DENIED:
/* kill_proc(fl->fl_pid, SIGLOST, 1); */

View File

@ -1437,14 +1437,6 @@ restart:
/* Mark the file as being 'closed' */
state->state = 0;
break;
case -EKEYEXPIRED:
/*
* User RPCSEC_GSS context has expired.
* We cannot recover this stateid now, so
* skip it and allow recovery thread to
* proceed.
*/
break;
case -NFS4ERR_ADMIN_REVOKED:
case -NFS4ERR_STALE_STATEID:
case -NFS4ERR_BAD_STATEID:
@ -1597,14 +1589,6 @@ static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
}
static void nfs4_warn_keyexpired(const char *s)
{
printk_ratelimited(KERN_WARNING "Error: state manager"
" encountered RPCSEC_GSS session"
" expired against NFSv4 server %s.\n",
s);
}
static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
{
switch (error) {
@ -1638,10 +1622,6 @@ static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
break;
case -EKEYEXPIRED:
/* Nothing we can do */
nfs4_warn_keyexpired(clp->cl_hostname);
break;
default:
dprintk("%s: failed to handle error %d for server %s\n",
__func__, error, clp->cl_hostname);
@ -1758,8 +1738,6 @@ static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
dprintk("%s: exit with error %d for server %s\n",
__func__, -EPROTONOSUPPORT, clp->cl_hostname);
return -EPROTONOSUPPORT;
case -EKEYEXPIRED:
nfs4_warn_keyexpired(clp->cl_hostname);
case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
* in nfs4_exchange_id */
default:
@ -1912,7 +1890,6 @@ again:
break;
case -EKEYEXPIRED:
nfs4_warn_keyexpired(clp->cl_hostname);
case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
* in nfs4_exchange_id */
status = -EKEYEXPIRED;

View File

@ -46,39 +46,6 @@
#define NFSDBG_FACILITY NFSDBG_PROC
/*
* wrapper to handle the -EKEYEXPIRED error message. This should generally
* only happen if using krb5 auth and a user's TGT expires. NFSv2 doesn't
* support the NFSERR_JUKEBOX error code, but we handle this situation in the
* same way that we handle that error with NFSv3.
*/
static int
nfs_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
{
int res;
do {
res = rpc_call_sync(clnt, msg, flags);
if (res != -EKEYEXPIRED)
break;
freezable_schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
res = -ERESTARTSYS;
} while (!fatal_signal_pending(current));
return res;
}
#define rpc_call_sync(clnt, msg, flags) nfs_rpc_wrapper(clnt, msg, flags)
static int
nfs_async_handle_expired_key(struct rpc_task *task)
{
if (task->tk_status != -EKEYEXPIRED)
return 0;
task->tk_status = 0;
rpc_restart_call(task);
rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
return 1;
}
/*
* Bare-bones access to getattr: this is for nfs_read_super.
*/
@ -364,8 +331,6 @@ static void nfs_proc_unlink_rpc_prepare(struct rpc_task *task, struct nfs_unlink
static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir)
{
if (nfs_async_handle_expired_key(task))
return 0;
nfs_mark_for_revalidate(dir);
return 1;
}
@ -385,8 +350,6 @@ static int
nfs_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
struct inode *new_dir)
{
if (nfs_async_handle_expired_key(task))
return 0;
nfs_mark_for_revalidate(old_dir);
nfs_mark_for_revalidate(new_dir);
return 1;
@ -642,9 +605,6 @@ static int nfs_read_done(struct rpc_task *task, struct nfs_read_data *data)
{
struct inode *inode = data->header->inode;
if (nfs_async_handle_expired_key(task))
return -EAGAIN;
nfs_invalidate_atime(inode);
if (task->tk_status >= 0) {
nfs_refresh_inode(inode, data->res.fattr);
@ -671,9 +631,6 @@ static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data)
{
struct inode *inode = data->header->inode;
if (nfs_async_handle_expired_key(task))
return -EAGAIN;
if (task->tk_status >= 0)
nfs_post_op_update_inode_force_wcc(inode, data->res.fattr);
return 0;

View File

@ -1381,6 +1381,7 @@ call_refreshresult(struct rpc_task *task)
return;
case -ETIMEDOUT:
rpc_delay(task, 3*HZ);
case -EKEYEXPIRED:
case -EAGAIN:
status = -EACCES;
if (!task->tk_cred_retry)