Merge remote branch 'origin/x86/urgent' into x86/asm

5 files changed, 95 insertions, 12 deletions

diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index d61e3b2..36d961f 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -146,7 +146,7 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 		while (rdir->head < rdir->tail) {
 			p9stat_init(&st);
 			err = p9stat_read(rdir->buf + rdir->head,
-						buflen - rdir->head, &st,
+						rdir->tail - rdir->head, &st,
 						fid->clnt->proto_version);
 			if (err) {
 				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 484e52b..2cb1a70 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -923,7 +923,7 @@ init_cifs(void)
 		goto out_unregister_filesystem;
 #endif
 #ifdef CONFIG_CIFS_DFS_UPCALL
-	rc = register_key_type(&key_type_dns_resolver);
+	rc = cifs_init_dns_resolver();
 	if (rc)
 		goto out_unregister_key_type;
 #endif
@@ -935,7 +935,7 @@ init_cifs(void)
 
  out_unregister_resolver_key:
 #ifdef CONFIG_CIFS_DFS_UPCALL
-	unregister_key_type(&key_type_dns_resolver);
+	cifs_exit_dns_resolver();
  out_unregister_key_type:
 #endif
 #ifdef CONFIG_CIFS_UPCALL
@@ -961,7 +961,7 @@ exit_cifs(void)
 	cifs_proc_clean();
 #ifdef CONFIG_CIFS_DFS_UPCALL
 	cifs_dfs_release_automount_timer();
-	unregister_key_type(&key_type_dns_resolver);
+	cifs_exit_dns_resolver();
 #endif
 #ifdef CONFIG_CIFS_UPCALL
 	unregister_key_type(&cifs_spnego_key_type);
diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c
index 4db2c5e..49315cb 100644
--- a/fs/cifs/dns_resolve.c
+++ b/fs/cifs/dns_resolve.c
@@ -24,12 +24,16 @@
  */
 
 #include <linux/slab.h>
+#include <linux/keyctl.h>
+#include <linux/key-type.h>
 #include <keys/user-type.h>
 #include "dns_resolve.h"
 #include "cifsglob.h"
 #include "cifsproto.h"
 #include "cifs_debug.h"
 
+static const struct cred *dns_resolver_cache;
+
 /* Checks if supplied name is IP address
  * returns:
  * 		1 - name is IP
@@ -94,6 +98,7 @@ struct key_type key_type_dns_resolver = {
 int
 dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
 {
+	const struct cred *saved_cred;
 	int rc = -EAGAIN;
 	struct key *rkey = ERR_PTR(-EAGAIN);
 	char *name;
@@ -133,8 +138,15 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
 		goto skip_upcall;
 	}
 
+	saved_cred = override_creds(dns_resolver_cache);
 	rkey = request_key(&key_type_dns_resolver, name, "");
+	revert_creds(saved_cred);
 	if (!IS_ERR(rkey)) {
+		if (!(rkey->perm & KEY_USR_VIEW)) {
+			down_read(&rkey->sem);
+			rkey->perm |= KEY_USR_VIEW;
+			up_read(&rkey->sem);
+		}
 		len = rkey->type_data.x[0];
 		data = rkey->payload.data;
 	} else {
@@ -165,4 +177,61 @@ out:
 	return rc;
 }
 
+int __init cifs_init_dns_resolver(void)
+{
+	struct cred *cred;
+	struct key *keyring;
+	int ret;
+
+	printk(KERN_NOTICE "Registering the %s key type\n",
+	       key_type_dns_resolver.name);
+
+	/* create an override credential set with a special thread keyring in
+	 * which DNS requests are cached
+	 *
+	 * this is used to prevent malicious redirections from being installed
+	 * with add_key().
+	 */
+	cred = prepare_kernel_cred(NULL);
+	if (!cred)
+		return -ENOMEM;
+
+	keyring = key_alloc(&key_type_keyring, ".dns_resolver", 0, 0, cred,
+			    (KEY_POS_ALL & ~KEY_POS_SETATTR) |
+			    KEY_USR_VIEW | KEY_USR_READ,
+			    KEY_ALLOC_NOT_IN_QUOTA);
+	if (IS_ERR(keyring)) {
+		ret = PTR_ERR(keyring);
+		goto failed_put_cred;
+	}
+
+	ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
+	if (ret < 0)
+		goto failed_put_key;
+
+	ret = register_key_type(&key_type_dns_resolver);
+	if (ret < 0)
+		goto failed_put_key;
+
+	/* instruct request_key() to use this special keyring as a cache for
+	 * the results it looks up */
+	cred->thread_keyring = keyring;
+	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
+	dns_resolver_cache = cred;
+	return 0;
+
+failed_put_key:
+	key_put(keyring);
+failed_put_cred:
+	put_cred(cred);
+	return ret;
+}
 
+void __exit cifs_exit_dns_resolver(void)
+{
+	key_revoke(dns_resolver_cache->thread_keyring);
+	unregister_key_type(&key_type_dns_resolver);
+	put_cred(dns_resolver_cache);
+	printk(KERN_NOTICE "Unregistered %s key type\n",
+	       key_type_dns_resolver.name);
+}
diff --git a/fs/cifs/dns_resolve.h b/fs/cifs/dns_resolve.h
index 966e928..26b9eaa 100644
--- a/fs/cifs/dns_resolve.h
+++ b/fs/cifs/dns_resolve.h
@@ -24,8 +24,8 @@
 #define _DNS_RESOLVE_H
 
 #ifdef __KERNEL__
-#include <linux/key-type.h>
-extern struct key_type key_type_dns_resolver;
+extern int __init cifs_init_dns_resolver(void);
+extern void __exit cifs_exit_dns_resolver(void);
 extern int dns_resolve_server_name_to_ip(const char *unc, char **ip_addr);
 #endif /* KERNEL */
 
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index f71246b..a7ac78f 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -28,6 +28,7 @@ static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
 	struct sysfs_dirent *target_sd = NULL;
 	struct sysfs_dirent *sd = NULL;
 	struct sysfs_addrm_cxt acxt;
+	enum kobj_ns_type ns_type;
 	int error;
 
 	BUG_ON(!name);
@@ -58,16 +59,29 @@ static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
 	if (!sd)
 		goto out_put;
 
-	if (sysfs_ns_type(parent_sd))
+	ns_type = sysfs_ns_type(parent_sd);
+	if (ns_type)
 		sd->s_ns = target->ktype->namespace(target);
 	sd->s_symlink.target_sd = target_sd;
 	target_sd = NULL;	/* reference is now owned by the symlink */
 
 	sysfs_addrm_start(&acxt, parent_sd);
-	if (warn)
-		error = sysfs_add_one(&acxt, sd);
-	else
-		error = __sysfs_add_one(&acxt, sd);
+	/* Symlinks must be between directories with the same ns_type */
+	if (!ns_type ||
+	    (ns_type == sysfs_ns_type(sd->s_symlink.target_sd->s_parent))) {
+		if (warn)
+			error = sysfs_add_one(&acxt, sd);
+		else
+			error = __sysfs_add_one(&acxt, sd);
+	} else {
+		error = -EINVAL;
+		WARN(1, KERN_WARNING
+			"sysfs: symlink across ns_types %s/%s -> %s/%s\n",
+			parent_sd->s_name,
+			sd->s_name,
+			sd->s_symlink.target_sd->s_parent->s_name,
+			sd->s_symlink.target_sd->s_name);
+	}
 	sysfs_addrm_finish(&acxt);
 
 	if (error)
@@ -122,7 +136,7 @@ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
 {
 	const void *ns = NULL;
 	spin_lock(&sysfs_assoc_lock);
-	if (targ->sd)
+	if (targ->sd && sysfs_ns_type(kobj->sd))
 		ns = targ->sd->s_ns;
 	spin_unlock(&sysfs_assoc_lock);
 	sysfs_hash_and_remove(kobj->sd, ns, name);