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>
This commit is contained in:
Trond Myklebust 2015-01-30 18:12:28 -05:00
parent e2c63e091e
commit 03a9a42a1a
4 changed files with 24 additions and 12 deletions

View File

@ -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 @@ static struct rpc_clnt *nsm_client_set(struct lockd_net *ln,
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, "

View File

@ -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;

View File

@ -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)) {

View File

@ -355,7 +355,8 @@ int rpcb_create_local(struct net *net)
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);