ext4: apply umask if ACL support is disabled

commit 484fd6c1de13b336806a967908a927cc0356e312 upstream.

The function ext4_init_acl() calls posix_acl_create() which is
responsible for applying the umask.  But without
CONFIG_EXT4_FS_POSIX_ACL, ext4_init_acl() is an empty inline function,
and nobody applies the umask.

This fixes a bug which causes the umask to be ignored with O_TMPFILE
on ext4:

 https://github.com/MusicPlayerDaemon/MPD/issues/558
 https://bugs.gentoo.org/show_bug.cgi?id=686142#c3
 https://bugzilla.kernel.org/show_bug.cgi?id=203625

Reviewed-by: "J. Bruce Fields" <bfields@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Link: https://lore.kernel.org/r/20230919081824.1096619-1-max.kellermann@ionos.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index 0c5a79c..ef4c19e 100644 (file)
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -68,6 +68,11 @@ extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
 static inline int
 ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
 {
+       /* usually, the umask is applied by posix_acl_create(), but if
+          ext4 ACL support is disabled at compile time, we need to do
+          it here, because posix_acl_create() will never be called */
+       inode->i_mode &= ~current_umask();
+
        return 0;
 }
 #endif  /* CONFIG_EXT4_FS_POSIX_ACL */