[PATCH AUTOSEL 4.19 5/8] nilfs2: fix incorrect masking of permission flags for symlinks

[Sasha Levin]

From: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>

[ Upstream commit 5924e6ec1585445f251ea92713eb15beb732622a ]

The permission flags of newly created symlinks are wrongly dropped on
nilfs2 with the current umask value even though symlinks should have 777
(rwxrwxrwx) permissions:

 $ umask
 0022
 $ touch file && ln -s file symlink; ls -l file symlink
 -rw-r--r--. 1 root root 0 Jun 23 16:29 file
 lrwxr-xr-x. 1 root root 4 Jun 23 16:29 symlink -> file

This fixes the bug by inserting a missing check that excludes
symlinks.

Link: https://lkml.kernel.org/r/1655974441-5612-1-git-send-email-konishi.ryusuke@xxxxxxxxx
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Reported-by: Tommy Pettersson <ptp@xxxxxxxxxxxxxx>
Reported-by: Ciprian Craciun <ciprian.craciun@xxxxxxxxx>
Tested-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/nilfs2/nilfs.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 8699bdc9e391..cca30f0f965c 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -198,6 +198,9 @@ static inline int nilfs_acl_chmod(struct inode *inode)
 
 static inline int nilfs_init_acl(struct inode *inode, struct inode *dir)
 {
+	if (S_ISLNK(inode->i_mode))
+		return 0;
+
 	inode->i_mode &= ~current_umask();
 	return 0;
 }
-- 
2.35.1