From 03a9a42a1a7e5b3e7919ddfacc1d1cc81882a955 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 30 Jan 2015 18:12:28 -0500 Subject: SUNRPC: NULL utsname dereference on NFS umount during namespace cleanup MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix an Oopsable condition when nsm_mon_unmon is called as part of the namespace cleanup, which now apparently happens after the utsname has been freed. Link: http://lkml.kernel.org/r/20150125220604.090121ae@neptune.home Reported-by: Bruno Prémont Cc: stable@vger.kernel.org # 3.18 Signed-off-by: Trond Myklebust diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c index 1cc6ec5..47a32b6 100644 --- a/fs/lockd/mon.c +++ b/fs/lockd/mon.c @@ -65,7 +65,7 @@ static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm) return (struct sockaddr *)&nsm->sm_addr; } -static struct rpc_clnt *nsm_create(struct net *net) +static struct rpc_clnt *nsm_create(struct net *net, const char *nodename) { struct sockaddr_in sin = { .sin_family = AF_INET, @@ -77,6 +77,7 @@ static struct rpc_clnt *nsm_create(struct net *net) .address = (struct sockaddr *)&sin, .addrsize = sizeof(sin), .servername = "rpc.statd", + .nodename = nodename, .program = &nsm_program, .version = NSM_VERSION, .authflavor = RPC_AUTH_NULL, @@ -102,7 +103,7 @@ out: return clnt; } -static struct rpc_clnt *nsm_client_get(struct net *net) +static struct rpc_clnt *nsm_client_get(struct net *net, const char *nodename) { struct rpc_clnt *clnt, *new; struct lockd_net *ln = net_generic(net, lockd_net_id); @@ -111,7 +112,7 @@ static struct rpc_clnt *nsm_client_get(struct net *net) if (clnt != NULL) goto out; - clnt = new = nsm_create(net); + clnt = new = nsm_create(net, nodename); if (IS_ERR(clnt)) goto out; @@ -190,19 +191,23 @@ int nsm_monitor(const struct nlm_host *host) struct nsm_res res; int status; struct rpc_clnt *clnt; + const char *nodename = NULL; dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name); if (nsm->sm_monitored) return 0; + if (host->h_rpcclnt) + nodename = host->h_rpcclnt->cl_nodename; + /* * Choose whether to record the caller_name or IP address of * this peer in the local rpc.statd's database. */ nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf; - clnt = nsm_client_get(host->net); + clnt = nsm_client_get(host->net, nodename); if (IS_ERR(clnt)) { status = PTR_ERR(clnt); dprintk("lockd: failed to create NSM upcall transport, " diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index d86acc6..598ba80 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -57,7 +57,7 @@ struct rpc_clnt { const struct rpc_timeout *cl_timeout; /* Timeout strategy */ int cl_nodelen; /* nodename length */ - char cl_nodename[UNX_MAXNODENAME]; + char cl_nodename[UNX_MAXNODENAME+1]; struct rpc_pipe_dir_head cl_pipedir_objects; struct rpc_clnt * cl_parent; /* Points to parent of clones */ struct rpc_rtt cl_rtt_default; @@ -112,6 +112,7 @@ struct rpc_create_args { struct sockaddr *saddress; const struct rpc_timeout *timeout; const char *servername; + const char *nodename; const struct rpc_program *program; u32 prognumber; /* overrides program->number */ u32 version; diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 05da12a..3f5d4d4 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -286,10 +286,8 @@ static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt, static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename) { - clnt->cl_nodelen = strlen(nodename); - if (clnt->cl_nodelen > UNX_MAXNODENAME) - clnt->cl_nodelen = UNX_MAXNODENAME; - memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen); + clnt->cl_nodelen = strlcpy(clnt->cl_nodename, + nodename, sizeof(clnt->cl_nodename)); } static int rpc_client_register(struct rpc_clnt *clnt, @@ -365,6 +363,7 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, const struct rpc_version *version; struct rpc_clnt *clnt = NULL; const struct rpc_timeout *timeout; + const char *nodename = args->nodename; int err; /* sanity check the name before trying to print it */ @@ -420,8 +419,10 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, atomic_set(&clnt->cl_count, 1); + if (nodename == NULL) + nodename = utsname()->nodename; /* save the nodename */ - rpc_clnt_set_nodename(clnt, utsname()->nodename); + rpc_clnt_set_nodename(clnt, nodename); err = rpc_client_register(clnt, args->authflavor, args->client_name); if (err) @@ -576,6 +577,7 @@ static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args, if (xprt == NULL) goto out_err; args->servername = xprt->servername; + args->nodename = clnt->cl_nodename; new = rpc_new_client(args, xprt, clnt); if (IS_ERR(new)) { diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c index 0520201..cf5770d 100644 --- a/net/sunrpc/rpcb_clnt.c +++ b/net/sunrpc/rpcb_clnt.c @@ -355,7 +355,8 @@ out: return result; } -static struct rpc_clnt *rpcb_create(struct net *net, const char *hostname, +static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename, + const char *hostname, struct sockaddr *srvaddr, size_t salen, int proto, u32 version) { @@ -365,6 +366,7 @@ static struct rpc_clnt *rpcb_create(struct net *net, const char *hostname, .address = srvaddr, .addrsize = salen, .servername = hostname, + .nodename = nodename, .program = &rpcb_program, .version = version, .authflavor = RPC_AUTH_UNIX, @@ -740,7 +742,9 @@ void rpcb_getport_async(struct rpc_task *task) dprintk("RPC: %5u %s: trying rpcbind version %u\n", task->tk_pid, __func__, bind_version); - rpcb_clnt = rpcb_create(xprt->xprt_net, xprt->servername, sap, salen, + rpcb_clnt = rpcb_create(xprt->xprt_net, + clnt->cl_nodename, + xprt->servername, sap, salen, xprt->prot, bind_version); if (IS_ERR(rpcb_clnt)) { status = PTR_ERR(rpcb_clnt); -- cgit v0.10.2