From: Jiri Slaby <jslaby@suse.cz>
Date: Tue, 13 Jun 2017 13:35:50 +0200
Subject: fs/fcntl: f_setown, allow returning error
Patch-mainline: v4.13-rc1
Git-commit: 393cc3f51135ea2520521f776ef3afdf3395c797
References: bnc#1006180

Allow f_setown to return an error value. We will fail in the next patch
with EINVAL for bad input to f_setown, so tile the path for the later
patch.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/fcntl.c         |    7 ++++---
 include/linux/fs.h |    2 +-
 net/socket.c       |    3 +--
 3 files changed, 6 insertions(+), 6 deletions(-)

--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -109,7 +109,7 @@ void __f_setown(struct file *filp, struc
 }
 EXPORT_SYMBOL(__f_setown);
 
-void f_setown(struct file *filp, unsigned long arg, int force)
+int f_setown(struct file *filp, unsigned long arg, int force)
 {
 	enum pid_type type;
 	struct pid *pid;
@@ -123,6 +123,8 @@ void f_setown(struct file *filp, unsigne
 	pid = find_vpid(who);
 	__f_setown(filp, pid, type, force);
 	rcu_read_unlock();
+
+	return 0;
 }
 EXPORT_SYMBOL(f_setown);
 
@@ -297,8 +299,7 @@ static long do_fcntl(int fd, unsigned in
 		force_successful_syscall_return();
 		break;
 	case F_SETOWN:
-		f_setown(filp, arg, 1);
-		err = 0;
+		err = f_setown(filp, arg, 1);
 		break;
 	case F_GETOWN_EX:
 		err = f_getown_ex(filp, arg);
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1249,7 +1249,7 @@ extern void fasync_free(struct fasync_st
 extern void kill_fasync(struct fasync_struct **, int, int);
 
 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 int 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);
--- a/net/socket.c
+++ b/net/socket.c
@@ -950,8 +950,7 @@ static long sock_ioctl(struct file *file
 			err = -EFAULT;
 			if (get_user(pid, (int __user *)argp))
 				break;
-			f_setown(sock->file, pid, 1);
-			err = 0;
+			err = f_setown(sock->file, pid, 1);
 			break;
 		case FIOGETOWN:
 		case SIOCGPGRP: