Messages in this thread Patch in this message |  | | | Subject | [PATCH] sunrpc: cache_register can use wrong module reference | | From | Bruce Allan <> | | Date | Tue, 02 Aug 2005 14:29:36 -0700 |
| |
[resending to Neil, Trond and linux-nfs list; initial copy to lkml]
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 fixes this by passing the address of the owning struct module to cache_register(). In addition, printk's were added to functions calling cache_unregister() to dump an error message on failure.
Signed-off-by: Bruce Allan <bwa@us.ibm.com>
diff -uprN -X linux-2.6.13-rc5/Documentation/dontdiff linux-2.6.13-rc5/fs/nfsd/export.c linux-2.6.13-rc5-rpc_cache_register/fs/nfsd/export.c --- linux-2.6.13-rc5/fs/nfsd/export.c 2005-08-01 21:45:48.000000000 -0700 +++ linux-2.6.13-rc5-rpc_cache_register/fs/nfsd/export.c 2005-08-02 13:20:50.000000000 -0700 @@ -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> @@ -1161,9 +1162,8 @@ nfsd_export_init(void) { dprintk("nfsd: initializing export module.\n"); - cache_register(&svc_export_cache); - cache_register(&svc_expkey_cache); - + cache_register(&svc_export_cache, THIS_MODULE); + cache_register(&svc_expkey_cache, THIS_MODULE); } /* diff -uprN -X linux-2.6.13-rc5/Documentation/dontdiff linux-2.6.13-rc5/fs/nfsd/nfs4idmap.c linux-2.6.13-rc5-rpc_cache_register/fs/nfsd/nfs4idmap.c --- linux-2.6.13-rc5/fs/nfsd/nfs4idmap.c 2005-08-01 21:45:48.000000000 -0700 +++ linux-2.6.13-rc5-rpc_cache_register/fs/nfsd/nfs4idmap.c 2005-08-02 13:20:50.000000000 -0700 @@ -397,15 +397,17 @@ static DefineSimpleCacheLookupMap(ent, n void nfsd_idmap_init(void) { - cache_register(&idtoname_cache); - cache_register(&nametoid_cache); + cache_register(&idtoname_cache, THIS_MODULE); + cache_register(&nametoid_cache, THIS_MODULE); } 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 -uprN -X linux-2.6.13-rc5/Documentation/dontdiff linux-2.6.13-rc5/include/linux/sunrpc/cache.h linux-2.6.13-rc5-rpc_cache_register/include/linux/sunrpc/cache.h --- linux-2.6.13-rc5/include/linux/sunrpc/cache.h 2005-08-01 21:45:48.000000000 -0700 +++ linux-2.6.13-rc5-rpc_cache_register/include/linux/sunrpc/cache.h 2005-08-02 13:20:50.000000000 -0700 @@ -278,7 +278,7 @@ extern int cache_check(struct cache_deta extern void cache_flush(void); extern void cache_purge(struct cache_detail *detail); #define NEVER (0x7FFFFFFF) -extern void cache_register(struct cache_detail *cd); +extern void cache_register(struct cache_detail *cd, struct module *owner); extern int cache_unregister(struct cache_detail *cd); extern void qword_add(char **bpp, int *lp, char *str); diff -uprN -X linux-2.6.13-rc5/Documentation/dontdiff linux-2.6.13-rc5/net/sunrpc/auth_gss/svcauth_gss.c linux-2.6.13-rc5-rpc_cache_register/net/sunrpc/auth_gss/svcauth_gss.c --- linux-2.6.13-rc5/net/sunrpc/auth_gss/svcauth_gss.c 2005-08-01 21:45:48.000000000 -0700 +++ linux-2.6.13-rc5-rpc_cache_register/net/sunrpc/auth_gss/svcauth_gss.c 2005-08-02 13:20:50.000000000 -0700 @@ -1065,8 +1065,8 @@ gss_svc_init(void) { int rv = svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss); if (rv == 0) { - cache_register(&rsc_cache); - cache_register(&rsi_cache); + cache_register(&rsc_cache, THIS_MODULE); + cache_register(&rsi_cache, THIS_MODULE); } return rv; } @@ -1074,7 +1074,9 @@ 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 "sunrpc: failed to unregister rsc cache\n"); + if (cache_unregister(&rsi_cache)) + printk(KERN_ERR "sunrpc: failed to unregister rsi cache\n"); svc_auth_unregister(RPC_AUTH_GSS); } diff -uprN -X linux-2.6.13-rc5/Documentation/dontdiff linux-2.6.13-rc5/net/sunrpc/cache.c linux-2.6.13-rc5-rpc_cache_register/net/sunrpc/cache.c --- linux-2.6.13-rc5/net/sunrpc/cache.c 2005-08-01 21:45:48.000000000 -0700 +++ linux-2.6.13-rc5-rpc_cache_register/net/sunrpc/cache.c 2005-08-02 13:20:50.000000000 -0700 @@ -172,12 +172,12 @@ static struct file_operations cache_flus static void do_cache_clean(void *data); static DECLARE_WORK(cache_cleaner, do_cache_clean, NULL); -void cache_register(struct cache_detail *cd) +void cache_register(struct cache_detail *cd, struct module *owner) { 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 = 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 = 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 = 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 = owner; p->data = cd; } } diff -uprN -X linux-2.6.13-rc5/Documentation/dontdiff linux-2.6.13-rc5/net/sunrpc/sunrpc_syms.c linux-2.6.13-rc5-rpc_cache_register/net/sunrpc/sunrpc_syms.c --- linux-2.6.13-rc5/net/sunrpc/sunrpc_syms.c 2005-08-01 21:45:48.000000000 -0700 +++ linux-2.6.13-rc5-rpc_cache_register/net/sunrpc/sunrpc_syms.c 2005-08-02 13:20:50.000000000 -0700 @@ -165,8 +165,8 @@ init_sunrpc(void) #ifdef CONFIG_PROC_FS rpc_proc_init(); #endif - cache_register(&auth_domain_cache); - cache_register(&ip_map_cache); + cache_register(&auth_domain_cache, THIS_MODULE); + cache_register(&ip_map_cache, THIS_MODULE); out: return err; } @@ -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
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |