When registering an RPC cache, cache_register() always sets the owner as the
sunrpc module. However, there are RPC caches owned by other modules. With
the incorrect owner setting, the real owning module can be removed potentially
with an open reference to the cache from userspace.
For example, if one were to stop the nfs server and unmount the nfsd
filesystem, the nfsd module could be removed eventhough rpc.idmapd had
references to the idtoname and nametoid caches (i.e.
/proc/net/rpc/nfs4.<cachename>/channel is still open). This resulted in a
system panic on one of our machines when attempting to restart the nfs
services after reloading the nfsd module.
The following patch adds a 'struct module *owner' field in struct
cache_detail. The owner is further assigned to the struct proc_dir_entry
in cache_register() so that the module cannot be unloaded while user-space
daemons have an open reference on the associated file under /proc.
Signed-off-by: Bruce Allan <bwa@us.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/hash.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/hash.h>
+#include <linux/module.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
}
struct cache_detail svc_expkey_cache = {
}
struct cache_detail svc_expkey_cache = {
.hash_size = EXPKEY_HASHMAX,
.hash_table = expkey_table,
.name = "nfsd.fh",
.hash_size = EXPKEY_HASHMAX,
.hash_table = expkey_table,
.name = "nfsd.fh",
return 0;
}
struct cache_detail svc_export_cache = {
return 0;
}
struct cache_detail svc_export_cache = {
.hash_size = EXPORT_HASHMAX,
.hash_table = export_table,
.name = "nfsd.export",
.hash_size = EXPORT_HASHMAX,
.hash_table = export_table,
.name = "nfsd.export",
static struct ent *idtoname_lookup(struct ent *, int);
static struct cache_detail idtoname_cache = {
static struct ent *idtoname_lookup(struct ent *, int);
static struct cache_detail idtoname_cache = {
.hash_size = ENT_HASHMAX,
.hash_table = idtoname_table,
.name = "nfs4.idtoname",
.hash_size = ENT_HASHMAX,
.hash_table = idtoname_table,
.name = "nfs4.idtoname",
static int nametoid_parse(struct cache_detail *, char *, int);
static struct cache_detail nametoid_cache = {
static int nametoid_parse(struct cache_detail *, char *, int);
static struct cache_detail nametoid_cache = {
.hash_size = ENT_HASHMAX,
.hash_table = nametoid_table,
.name = "nfs4.nametoid",
.hash_size = ENT_HASHMAX,
.hash_table = nametoid_table,
.name = "nfs4.nametoid",
void
nfsd_idmap_shutdown(void)
{
void
nfsd_idmap_shutdown(void)
{
- cache_unregister(&idtoname_cache);
- cache_unregister(&nametoid_cache);
+ if (cache_unregister(&idtoname_cache))
+ printk(KERN_ERR "nfsd: failed to unregister idtoname cache\n");
+ if (cache_unregister(&nametoid_cache))
+ printk(KERN_ERR "nfsd: failed to unregister nametoid cache\n");
#define CACHE_NEW_EXPIRY 120 /* keep new things pending confirmation for 120 seconds */
struct cache_detail {
#define CACHE_NEW_EXPIRY 120 /* keep new things pending confirmation for 120 seconds */
struct cache_detail {
int hash_size;
struct cache_head ** hash_table;
rwlock_t hash_lock;
int hash_size;
struct cache_head ** hash_table;
rwlock_t hash_lock;
}
static struct cache_detail rsi_cache = {
}
static struct cache_detail rsi_cache = {
.hash_size = RSI_HASHMAX,
.hash_table = rsi_table,
.name = "auth.rpcsec.init",
.hash_size = RSI_HASHMAX,
.hash_table = rsi_table,
.name = "auth.rpcsec.init",
}
static struct cache_detail rsc_cache = {
}
static struct cache_detail rsc_cache = {
.hash_size = RSC_HASHMAX,
.hash_table = rsc_table,
.name = "auth.rpcsec.context",
.hash_size = RSC_HASHMAX,
.hash_table = rsc_table,
.name = "auth.rpcsec.context",
void
gss_svc_shutdown(void)
{
void
gss_svc_shutdown(void)
{
- cache_unregister(&rsc_cache);
- cache_unregister(&rsi_cache);
+ if (cache_unregister(&rsc_cache))
+ printk(KERN_ERR "auth_rpcgss: failed to unregister rsc cache\n");
+ if (cache_unregister(&rsi_cache))
+ printk(KERN_ERR "auth_rpcgss: failed to unregister rsi cache\n");
svc_auth_unregister(RPC_AUTH_GSS);
}
svc_auth_unregister(RPC_AUTH_GSS);
}
cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc);
if (cd->proc_ent) {
struct proc_dir_entry *p;
cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc);
if (cd->proc_ent) {
struct proc_dir_entry *p;
- cd->proc_ent->owner = THIS_MODULE;
+ cd->proc_ent->owner = cd->owner;
cd->channel_ent = cd->content_ent = NULL;
p = create_proc_entry("flush", S_IFREG|S_IRUSR|S_IWUSR,
cd->channel_ent = cd->content_ent = NULL;
p = create_proc_entry("flush", S_IFREG|S_IRUSR|S_IWUSR,
cd->flush_ent = p;
if (p) {
p->proc_fops = &cache_flush_operations;
cd->flush_ent = p;
if (p) {
p->proc_fops = &cache_flush_operations;
- p->owner = THIS_MODULE;
cd->channel_ent = p;
if (p) {
p->proc_fops = &cache_file_operations;
cd->channel_ent = p;
if (p) {
p->proc_fops = &cache_file_operations;
- p->owner = THIS_MODULE;
cd->content_ent = p;
if (p) {
p->proc_fops = &content_file_operations;
cd->content_ent = p;
if (p) {
p->proc_fops = &content_file_operations;
- p->owner = THIS_MODULE;
{
unregister_rpc_pipefs();
rpc_destroy_mempool();
{
unregister_rpc_pipefs();
rpc_destroy_mempool();
- cache_unregister(&auth_domain_cache);
- cache_unregister(&ip_map_cache);
+ if (cache_unregister(&auth_domain_cache))
+ printk(KERN_ERR "sunrpc: failed to unregister auth_domain cache\n");
+ if (cache_unregister(&ip_map_cache))
+ printk(KERN_ERR "sunrpc: failed to unregister ip_map cache\n");
#ifdef RPC_DEBUG
rpc_unregister_sysctl();
#endif
#ifdef RPC_DEBUG
rpc_unregister_sysctl();
#endif
struct cache_detail auth_domain_cache = {
struct cache_detail auth_domain_cache = {
.hash_size = DN_HASHMAX,
.hash_table = auth_domain_table,
.name = "auth.domain",
.hash_size = DN_HASHMAX,
.hash_table = auth_domain_table,
.name = "auth.domain",
struct cache_detail ip_map_cache = {
struct cache_detail ip_map_cache = {
.hash_size = IP_HASHMAX,
.hash_table = ip_table,
.name = "auth.unix.ip",
.hash_size = IP_HASHMAX,
.hash_table = ip_table,
.name = "auth.unix.ip",