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 @@ 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, "