From ff0cdcc049c0c4b36a23eb6880a116d5f78e90e3 Mon Sep 17 00:00:00 2001
From: Konrad <32096130+ewentual@users.noreply.github.com>
Date: Sat, 9 Jun 2018 12:03:07 +0200
Subject: [PATCH] Update base.c

---
 fs/proc/base.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 64dd67f74cd..4484fa0a8ed 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1803,7 +1803,7 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
 			rcu_read_lock();
 			file = fcheck_files(files, fd);
 			if (file) {
-				unsigned i_mode, f_mode = file->f_mode;
+				unsigned f_mode = file->f_mode;
 
 				rcu_read_unlock();
 				put_files_struct(files);
@@ -1819,12 +1819,14 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
 					inode->i_gid = 0;
 				}
 
-				i_mode = S_IFLNK;
-				if (f_mode & FMODE_READ)
-					i_mode |= S_IRUSR | S_IXUSR;
-				if (f_mode & FMODE_WRITE)
-					i_mode |= S_IWUSR | S_IXUSR;
-				inode->i_mode = i_mode;
+				if (S_ISLNK(inode->i_mode)) {
+					unsigned i_mode = S_IFLNK;
+					if (f_mode & FMODE_READ)
+						i_mode |= S_IRUSR | S_IXUSR;
+					if (f_mode & FMODE_WRITE)
+						i_mode |= S_IWUSR | S_IXUSR;
+					inode->i_mode = i_mode;
+				}
 
 				security_task_to_inode(task, inode);
 				put_task_struct(task);
@@ -1859,6 +1861,7 @@ static struct dentry *proc_fd_instantiate(struct inode *dir,
 	ei = PROC_I(inode);
 	ei->fd = fd;
 
+	inode->i_mode = S_IFLNK;
 	inode->i_op = &proc_pid_link_inode_operations;
 	inode->i_size = 64;
 	ei->op.proc_get_link = proc_fd_link;
