tree cdf9acab7e7fda7ae1eae152861d4048b7f6dffc
parent d013a068a5675ecd8e71f585a44e7af0798a4307
author Bruce Allan <[EMAIL PROTECTED]> Wed, 07 Sep 2005 05:17:08 -0700
committer Linus Torvalds <[EMAIL PROTECTED]> Thu, 08 Sep 2005 06:57:25 -0700

[PATCH] sunrpc: cache_register can use wrong module reference

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 <[EMAIL PROTECTED]>
Cc: Trond Myklebust <[EMAIL PROTECTED]>
Cc: Neil Brown <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>

 fs/nfsd/export.c                  |    3 +++
 fs/nfsd/nfs4idmap.c               |    8 ++++++--
 include/linux/sunrpc/cache.h      |    1 +
 net/sunrpc/auth_gss/svcauth_gss.c |    8 ++++++--
 net/sunrpc/cache.c                |    8 ++++----
 net/sunrpc/sunrpc_syms.c          |    6 ++++--
 net/sunrpc/svcauth.c              |    1 +
 net/sunrpc/svcauth_unix.c         |    1 +
 8 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -26,6 +26,7 @@
 #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>
@@ -221,6 +222,7 @@ static int expkey_show(struct seq_file *
 }
        
 struct cache_detail svc_expkey_cache = {
+       .owner          = THIS_MODULE,
        .hash_size      = EXPKEY_HASHMAX,
        .hash_table     = expkey_table,
        .name           = "nfsd.fh",
@@ -456,6 +458,7 @@ static int svc_export_show(struct seq_fi
        return 0;
 }
 struct cache_detail svc_export_cache = {
+       .owner          = THIS_MODULE,
        .hash_size      = EXPORT_HASHMAX,
        .hash_table     = export_table,
        .name           = "nfsd.export",
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -187,6 +187,7 @@ static int         idtoname_parse(struct
 static struct ent *idtoname_lookup(struct ent *, int);
 
 static struct cache_detail idtoname_cache = {
+       .owner          = THIS_MODULE,
        .hash_size      = ENT_HASHMAX,
        .hash_table     = idtoname_table,
        .name           = "nfs4.idtoname",
@@ -320,6 +321,7 @@ static struct ent *nametoid_lookup(struc
 static int         nametoid_parse(struct cache_detail *, char *, int);
 
 static struct cache_detail nametoid_cache = {
+       .owner          = THIS_MODULE,
        .hash_size      = ENT_HASHMAX,
        .hash_table     = nametoid_table,
        .name           = "nfs4.nametoid",
@@ -404,8 +406,10 @@ nfsd_idmap_init(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");
 }
 
 /*
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -60,6 +60,7 @@ struct cache_head {
 #define        CACHE_NEW_EXPIRY 120    /* keep new things pending confirmation 
for 120 seconds */
 
 struct cache_detail {
+       struct module *         owner;
        int                     hash_size;
        struct cache_head **    hash_table;
        rwlock_t                hash_lock;
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c 
b/net/sunrpc/auth_gss/svcauth_gss.c
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -250,6 +250,7 @@ out:
 }
 
 static struct cache_detail rsi_cache = {
+       .owner          = THIS_MODULE,
        .hash_size      = RSI_HASHMAX,
        .hash_table     = rsi_table,
        .name           = "auth.rpcsec.init",
@@ -436,6 +437,7 @@ out:
 }
 
 static struct cache_detail rsc_cache = {
+       .owner          = THIS_MODULE,
        .hash_size      = RSC_HASHMAX,
        .hash_table     = rsc_table,
        .name           = "auth.rpcsec.context",
@@ -1074,7 +1076,9 @@ gss_svc_init(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);
 }
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -177,7 +177,7 @@ void cache_register(struct cache_detail 
        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,
@@ -185,7 +185,7 @@ void cache_register(struct cache_detail 
                cd->flush_ent =  p;
                if (p) {
                        p->proc_fops = &cache_flush_operations;
-                       p->owner = THIS_MODULE;
+                       p->owner = cd->owner;
                        p->data = cd;
                }
  
@@ -195,7 +195,7 @@ void cache_register(struct cache_detail 
                        cd->channel_ent = p;
                        if (p) {
                                p->proc_fops = &cache_file_operations;
-                               p->owner = THIS_MODULE;
+                               p->owner = cd->owner;
                                p->data = cd;
                        }
                }
@@ -205,7 +205,7 @@ void cache_register(struct cache_detail 
                        cd->content_ent = p;
                        if (p) {
                                p->proc_fops = &content_file_operations;
-                               p->owner = THIS_MODULE;
+                               p->owner = cd->owner;
                                p->data = cd;
                        }
                }
diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -176,8 +176,10 @@ cleanup_sunrpc(void)
 {
        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
diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c
--- a/net/sunrpc/svcauth.c
+++ b/net/sunrpc/svcauth.c
@@ -143,6 +143,7 @@ static void auth_domain_drop(struct cach
 
 
 struct cache_detail auth_domain_cache = {
+       .owner          = THIS_MODULE,
        .hash_size      = DN_HASHMAX,
        .hash_table     = auth_domain_table,
        .name           = "auth.domain",
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -242,6 +242,7 @@ static int ip_map_show(struct seq_file *
        
 
 struct cache_detail ip_map_cache = {
+       .owner          = THIS_MODULE,
        .hash_size      = IP_HASHMAX,
        .hash_table     = ip_table,
        .name           = "auth.unix.ip",
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to