security: make security_file_set_fowner, f_setown and __f_setown void return

security_file_set_fowner always returns 0, so make it f_setown and
__f_setown void return functions and fix up the error handling in the
callers.

Cc: linux-security-module@vger.kernel.org
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

drivers/net/tun.c

@@ -2152,9 +2152,7 @@ static int tun_chr_fasync(int fd, struct file *file, int on)
 		goto out;
 
 	if (on) {
-		ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
-		if (ret)
-			goto out;
+		__f_setown(file, task_pid(current), PIDTYPE_PID, 0);
 		tfile->flags |= TUN_FASYNC;
 	} else
 		tfile->flags &= ~TUN_FASYNC;

drivers/tty/tty_io.c

@@ -2163,8 +2163,9 @@ static int __tty_fasync(int fd, struct file *filp, int on)
 		}
 		get_pid(pid);
 		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-		retval = __f_setown(filp, pid, type, 0);
+		__f_setown(filp, pid, type, 0);
 		put_pid(pid);
+		retval = 0;
 	}
 out:
 	return retval;

fs/fcntl.c

@@ -98,26 +98,19 @@ static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
 	write_unlock_irq(&filp->f_owner.lock);
 }
 
-int __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
+void __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
 		int force)
 {
-	int err;
-
-	err = security_file_set_fowner(filp);
-	if (err)
-		return err;
-
+	security_file_set_fowner(filp);
 	f_modown(filp, pid, type, force);
-	return 0;
 }
 EXPORT_SYMBOL(__f_setown);
 
-int f_setown(struct file *filp, unsigned long arg, int force)
+void f_setown(struct file *filp, unsigned long arg, int force)
 {
 	enum pid_type type;
 	struct pid *pid;
 	int who = arg;
-	int result;
 	type = PIDTYPE_PID;
 	if (who < 0) {
 		type = PIDTYPE_PGID;
@@ -125,9 +118,8 @@ int f_setown(struct file *filp, unsigned long arg, int force)
 	}
 	rcu_read_lock();
 	pid = find_vpid(who);
-	result = __f_setown(filp, pid, type, force);
+	__f_setown(filp, pid, type, force);
 	rcu_read_unlock();
-	return result;
 }
 EXPORT_SYMBOL(f_setown);
 
@@ -181,7 +173,7 @@ static int f_setown_ex(struct file *filp, unsigned long arg)
 	if (owner.pid && !pid)
 		ret = -ESRCH;
 	else
-		ret = __f_setown(filp, pid, type, 1);
+		 __f_setown(filp, pid, type, 1);
 	rcu_read_unlock();
 
 	return ret;
@@ -302,7 +294,8 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
 		force_successful_syscall_return();
 		break;
 	case F_SETOWN:
-		err = f_setown(filp, arg, 1);
+		f_setown(filp, arg, 1);
+		err = 0;
 		break;
 	case F_GETOWN_EX:
 		err = f_getown_ex(filp, arg);

fs/locks.c

@@ -1776,7 +1776,7 @@ static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg)
 	if (!fasync_insert_entry(fd, filp, &ret->fl_fasync, new))
 		new = NULL;
 
-	error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
+	__f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
 out_unlock:
 	spin_unlock(&inode->i_lock);
 	if (fl)

fs/notify/dnotify/dnotify.c

@@ -346,13 +346,7 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
 		goto out;
 	}
 
-	error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
-	if (error) {
-		/* if we added, we must shoot */
-		if (dn_mark == new_dn_mark)
-			destroy = 1;
-		goto out;
-	}
+	__f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
 
 	error = attach_dn(dn, dn_mark, id, fd, filp, mask);
 	/* !error means that we attached the dn to the dn_mark, so don't free it */

include/linux/fs.h

@@ -1139,8 +1139,8 @@ extern void fasync_free(struct fasync_struct *);
 /* can be called from interrupts */
 extern void kill_fasync(struct fasync_struct **, int, int);
 
-extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
-extern int f_setown(struct file *filp, unsigned long arg, int force);
+extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
+extern void f_setown(struct file *filp, unsigned long arg, int force);
 extern void f_delown(struct file *filp);
 extern pid_t f_getown(struct file *filp);
 extern int send_sigurg(struct fown_struct *fown);

include/linux/security.h

@@ -1559,7 +1559,7 @@ struct security_operations {
 	int (*file_lock) (struct file *file, unsigned int cmd);
 	int (*file_fcntl) (struct file *file, unsigned int cmd,
 			   unsigned long arg);
-	int (*file_set_fowner) (struct file *file);
+	void (*file_set_fowner) (struct file *file);
 	int (*file_send_sigiotask) (struct task_struct *tsk,
 				    struct fown_struct *fown, int sig);
 	int (*file_receive) (struct file *file);
@@ -1834,7 +1834,7 @@ int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
 			   unsigned long prot);
 int security_file_lock(struct file *file, unsigned int cmd);
 int security_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg);
-int security_file_set_fowner(struct file *file);
+void security_file_set_fowner(struct file *file);
 int security_file_send_sigiotask(struct task_struct *tsk,
 				 struct fown_struct *fown, int sig);
 int security_file_receive(struct file *file);
@@ -2312,9 +2312,9 @@ static inline int security_file_fcntl(struct file *file, unsigned int cmd,
 	return 0;
 }
 
-static inline int security_file_set_fowner(struct file *file)
+static inline void security_file_set_fowner(struct file *file)
 {
-	return 0;
+	return;
 }
 
 static inline int security_file_send_sigiotask(struct task_struct *tsk,

net/socket.c

@@ -1069,7 +1069,8 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 			err = -EFAULT;
 			if (get_user(pid, (int __user *)argp))
 				break;
-			err = f_setown(sock->file, pid, 1);
+			f_setown(sock->file, pid, 1);
+			err = 0;
 			break;
 		case FIOGETOWN:
 		case SIOCGPGRP:

security/capability.c

@@ -343,9 +343,9 @@ static int cap_file_fcntl(struct file *file, unsigned int cmd,
 	return 0;
 }
 
-static int cap_file_set_fowner(struct file *file)
+static void cap_file_set_fowner(struct file *file)
 {
-	return 0;
+	return;
 }
 
 static int cap_file_send_sigiotask(struct task_struct *tsk,

security/security.c

@@ -775,9 +775,9 @@ int security_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
 	return security_ops->file_fcntl(file, cmd, arg);
 }
 
-int security_file_set_fowner(struct file *file)
+void security_file_set_fowner(struct file *file)
 {
-	return security_ops->file_set_fowner(file);
+	security_ops->file_set_fowner(file);
 }
 
 int security_file_send_sigiotask(struct task_struct *tsk,

security/selinux/hooks.c

@@ -3346,14 +3346,12 @@ static int selinux_file_fcntl(struct file *file, unsigned int cmd,
 	return err;
 }
 
-static int selinux_file_set_fowner(struct file *file)
+static void selinux_file_set_fowner(struct file *file)
 {
 	struct file_security_struct *fsec;
 
 	fsec = file->f_security;
 	fsec->fown_sid = current_sid();
-
-	return 0;
 }
 
 static int selinux_file_send_sigiotask(struct task_struct *tsk,

security/smack/smack_lsm.c

@@ -1390,12 +1390,11 @@ static int smack_mmap_file(struct file *file,
  * Returns 0
  * Further research may be required on this one.
  */
-static int smack_file_set_fowner(struct file *file)
+static void smack_file_set_fowner(struct file *file)
 {
 	struct smack_known *skp = smk_of_current();
 
 	file->f_security = skp->smk_known;
-	return 0;
 }
 
 /**