Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Two small cifs fixes, including one spnego upcall cifs security fix
  for stable"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Remove some obsolete comments
  cifs: Create dedicated keyring for spnego operations

3 files changed, 72 insertions, 8 deletions

diff --git a/fs/cifs/cifs_spnego.c b/fs/cifs/cifs_spnego.c
index 6908080e9b6d..b611fc2e8984 100644
--- a/fs/cifs/cifs_spnego.c
+++ b/fs/cifs/cifs_spnego.c
@@ -24,10 +24,13 @@
 #include <linux/string.h>
 #include <keys/user-type.h>
 #include <linux/key-type.h>
+#include <linux/keyctl.h>
 #include <linux/inet.h>
 #include "cifsglob.h"
 #include "cifs_spnego.h"
 #include "cifs_debug.h"
+#include "cifsproto.h"
+static const struct cred *spnego_cred;
 
 /* create a new cifs key */
 static int
@@ -102,6 +105,7 @@ cifs_get_spnego_key(struct cifs_ses *sesInfo)
 	size_t desc_len;
 	struct key *spnego_key;
 	const char *hostname = server->hostname;
+	const struct cred *saved_cred;
 
 	/* length of fields (with semicolons): ver=0xyz ip4=ipaddress
 	   host=hostname sec=mechanism uid=0xFF user=username */
@@ -163,7 +167,9 @@ cifs_get_spnego_key(struct cifs_ses *sesInfo)
 	sprintf(dp, ";pid=0x%x", current->pid);
 
 	cifs_dbg(FYI, "key description = %s\n", description);
+	saved_cred = override_creds(spnego_cred);
 	spnego_key = request_key(&cifs_spnego_key_type, description, "");
+	revert_creds(saved_cred);
 
 #ifdef CONFIG_CIFS_DEBUG2
 	if (cifsFYI && !IS_ERR(spnego_key)) {
@@ -177,3 +183,64 @@ out:
 	kfree(description);
 	return spnego_key;
 }
+
+int
+init_cifs_spnego(void)
+{
+	struct cred *cred;
+	struct key *keyring;
+	int ret;
+
+	cifs_dbg(FYI, "Registering the %s key type\n",
+		 cifs_spnego_key_type.name);
+
+	/*
+	 * Create an override credential set with special thread keyring for
+	 * spnego upcalls.
+	 */
+
+	cred = prepare_kernel_cred(NULL);
+	if (!cred)
+		return -ENOMEM;
+
+	keyring = keyring_alloc(".cifs_spnego",
+				GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
+				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				KEY_USR_VIEW | KEY_USR_READ,
+				KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
+	if (IS_ERR(keyring)) {
+		ret = PTR_ERR(keyring);
+		goto failed_put_cred;
+	}
+
+	ret = register_key_type(&cifs_spnego_key_type);
+	if (ret < 0)
+		goto failed_put_key;
+
+	/*
+	 * instruct request_key() to use this special keyring as a cache for
+	 * the results it looks up
+	 */
+	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
+	cred->thread_keyring = keyring;
+	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
+	spnego_cred = cred;
+
+	cifs_dbg(FYI, "cifs spnego keyring: %d\n", key_serial(keyring));
+	return 0;
+
+failed_put_key:
+	key_put(keyring);
+failed_put_cred:
+	put_cred(cred);
+	return ret;
+}
+
+void
+exit_cifs_spnego(void)
+{
+	key_revoke(spnego_cred->thread_keyring);
+	unregister_key_type(&cifs_spnego_key_type);
+	put_cred(spnego_cred);
+	cifs_dbg(FYI, "Unregistered %s key type\n", cifs_spnego_key_type.name);
+}
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 08fa36e5b2bc..5d8b7edf8a8f 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -890,7 +890,6 @@ const struct inode_operations cifs_dir_inode_ops = {
 	.rmdir = cifs_rmdir,
 	.rename2 = cifs_rename2,
 	.permission = cifs_permission,
-/*	revalidate:cifs_revalidate,   */
 	.setattr = cifs_setattr,
 	.symlink = cifs_symlink,
 	.mknod   = cifs_mknod,
@@ -901,9 +900,8 @@ const struct inode_operations cifs_dir_inode_ops = {
 };
 
 const struct inode_operations cifs_file_inode_ops = {
-/*	revalidate:cifs_revalidate, */
 	.setattr = cifs_setattr,
-	.getattr = cifs_getattr, /* do we need this anymore? */
+	.getattr = cifs_getattr,
 	.permission = cifs_permission,
 	.setxattr = generic_setxattr,
 	.getxattr = generic_getxattr,
@@ -915,9 +913,6 @@ const struct inode_operations cifs_symlink_inode_ops = {
 	.readlink = generic_readlink,
 	.get_link = cifs_get_link,
 	.permission = cifs_permission,
-	/* BB add the following two eventually */
-	/* revalidate: cifs_revalidate,
-	   setattr:    cifs_notify_change, *//* BB do we need notify change */
 	.setxattr = generic_setxattr,
 	.getxattr = generic_getxattr,
 	.listxattr = cifs_listxattr,
@@ -1303,7 +1298,7 @@ init_cifs(void)
 		goto out_destroy_mids;
 
 #ifdef CONFIG_CIFS_UPCALL
-	rc = register_key_type(&cifs_spnego_key_type);
+	rc = init_cifs_spnego();
 	if (rc)
 		goto out_destroy_request_bufs;
 #endif /* CONFIG_CIFS_UPCALL */
@@ -1326,7 +1321,7 @@ out_init_cifs_idmap:
 out_register_key_type:
 #endif
 #ifdef CONFIG_CIFS_UPCALL
-	unregister_key_type(&cifs_spnego_key_type);
+	exit_cifs_spnego();
 out_destroy_request_bufs:
 #endif
 	cifs_destroy_request_bufs();
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 0f9a6bc4ba43..1243bd326591 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -58,6 +58,8 @@ do {								\
 } while (0)
 extern int init_cifs_idmap(void);
 extern void exit_cifs_idmap(void);
+extern int init_cifs_spnego(void);
+extern void exit_cifs_spnego(void);
 extern char *build_path_from_dentry(struct dentry *);
 extern char *cifs_build_path_to_root(struct smb_vol *vol,
 				     struct cifs_sb_info *cifs_sb,