SUNRPC: NULL utsname dereference on NFS umount during namespace cleanup
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 <bonbons@linux-vserver.org>
Cc: stable@vger.kernel.org # 3.18
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
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 @@
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 @@
.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 @@
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 @@
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 @@
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 @@
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 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 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 @@
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 @@
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 @@
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 @@
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 @@
.address = srvaddr,
.addrsize = salen,
.servername = hostname,
+ .nodename = nodename,
.program = &rpcb_program,
.version = version,
.authflavor = RPC_AUTH_UNIX,
@@ -740,7 +742,9 @@
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);
