From 1de7eea92946d7b581a8cd26084410913c80e594 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 3 Dec 2018 11:30:30 +1100 Subject: SUNRPC: add side channel to use non-generic cred for rpc call. The credential passed in rpc_message.rpc_cred is always a generic credential except in one instance. When gss_destroying_context() calls rpc_call_null(), it passes a specific credential that it needs to destroy. In this case the RPC acts *on* the credential rather than being authorized by it. This special case deserves explicit support and providing that will mean that rpc_message.rpc_cred is *always* generic, allowing some optimizations. So add "tk_op_cred" to rpc_task and "rpc_op_cred" to the setup data. Use this to pass the cred down from rpc_call_null(), and have rpcauth_bindcred() notice it and bind it in place. Credit to kernel test robot for finding a bug in earlier version of this patch. Signed-off-by: NeilBrown Signed-off-by: Anna Schumaker --- include/linux/sunrpc/sched.h | 2 ++ net/sunrpc/auth.c | 6 +++++- net/sunrpc/clnt.c | 2 +- net/sunrpc/sched.c | 3 +++ 4 files changed, 11 insertions(+), 2 deletions(-) diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index bd722ebc70b7..4e2b893b83a8 100644 --- a/include/linux/sunrpc/sched.h +++ b/include/linux/sunrpc/sched.h @@ -71,6 +71,7 @@ struct rpc_task { struct rpc_clnt * tk_client; /* RPC client */ struct rpc_xprt * tk_xprt; /* Transport */ + struct rpc_cred * tk_op_cred; /* cred being operated on */ struct rpc_rqst * tk_rqstp; /* RPC request */ @@ -105,6 +106,7 @@ struct rpc_task_setup { struct rpc_task *task; struct rpc_clnt *rpc_client; struct rpc_xprt *rpc_xprt; + struct rpc_cred *rpc_op_cred; /* credential being operated on */ const struct rpc_message *rpc_message; const struct rpc_call_ops *callback_ops; void *callback_data; diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index dcfcc590b34e..27d90578e7a0 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -751,7 +751,11 @@ rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags) if (flags & RPC_TASK_ASYNC) lookupflags |= RPCAUTH_LOOKUP_NEW; - if (cred != NULL && cred != &machine_cred) + if (task->tk_op_cred) + /* Task must use exactly this rpc_cred */ + new = task->tk_op_cred->cr_ops->crbind(task, task->tk_op_cred, + lookupflags); + else if (cred != NULL && cred != &machine_cred) new = cred->cr_ops->crbind(task, cred, lookupflags); else if (cred == &machine_cred) new = rpcauth_bind_machine_cred(task, lookupflags); diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 26bea2301045..4cb697cfb377 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -2534,12 +2534,12 @@ struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt, { struct rpc_message msg = { .rpc_proc = &rpcproc_null, - .rpc_cred = cred, }; struct rpc_task_setup task_setup_data = { .rpc_client = clnt, .rpc_xprt = xprt, .rpc_message = &msg, + .rpc_op_cred = cred, .callback_ops = (ops != NULL) ? ops : &rpc_default_ops, .callback_data = data, .flags = flags, diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index 57ca5bead1cb..c9f65037a6ad 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -997,6 +997,8 @@ static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *ta task->tk_xprt = xprt_get(task_setup_data->rpc_xprt); + task->tk_op_cred = get_rpccred(task_setup_data->rpc_op_cred); + if (task->tk_ops->rpc_call_prepare != NULL) task->tk_action = rpc_prepare_task; @@ -1054,6 +1056,7 @@ static void rpc_free_task(struct rpc_task *task) { unsigned short tk_flags = task->tk_flags; + put_rpccred(task->tk_op_cred); rpc_release_calldata(task->tk_ops, task->tk_calldata); if (tk_flags & RPC_TASK_DYNAMIC) { -- cgit v1.2.3-58-ga151