From: Bruce Allan Date: Tue, 6 Sep 2005 22:17:08 +0000 (-0700) Subject: [PATCH] sunrpc: cache_register can use wrong module reference X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f35279d3f713e5c97b98cbdbf47d98f79942c11f;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git [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./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 Cc: Trond Myklebust Cc: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index 9a11aa39e2e4..057aff745506 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -221,6 +222,7 @@ static int expkey_show(struct seq_file *m, } 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_file *m, 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 index 5605a26efc57..13369650cdf9 100644 --- a/fs/nfsd/nfs4idmap.c +++ b/fs/nfsd/nfs4idmap.c @@ -187,6 +187,7 @@ static int idtoname_parse(struct cache_detail *, char *, int); 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(struct ent *, int); 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 index 6864063d1b9f..c4e3ea7cf154 100644 --- 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 index 5c8fe3bfc494..e3308195374e 100644 --- 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 index 900f5bc7e336..f509e9992767 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -177,7 +177,7 @@ void cache_register(struct cache_detail *cd) 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) 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) 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) 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 index 62a073495276..ed48ff022d35 100644 --- 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 index bde8147ef2db..dda4f0c63511 100644 --- a/net/sunrpc/svcauth.c +++ b/net/sunrpc/svcauth.c @@ -143,6 +143,7 @@ static void auth_domain_drop(struct cache_head *item, struct cache_detail *cd) 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 index d6baf6fdf8a9..cac2e774dd81 100644 --- a/net/sunrpc/svcauth_unix.c +++ b/net/sunrpc/svcauth_unix.c @@ -242,6 +242,7 @@ static int ip_map_show(struct seq_file *m, struct cache_detail ip_map_cache = { + .owner = THIS_MODULE, .hash_size = IP_HASHMAX, .hash_table = ip_table, .name = "auth.unix.ip",