diff options
| -rw-r--r-- | fs/overlayfs/super.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index a64f0f4820e..508cf19a217 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -569,6 +569,12 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) goto out_put_upper_mnt; } + /* + * Make lower_mnt R/O. That way fchmod/fchown on lower file + * will fail instead of modifying lower fs. + */ + ufs->lower_mnt->mnt_flags |= MNT_READONLY; + /* If the upper fs is r/o, we mark overlayfs r/o too */ if (ufs->upper_mnt->mnt_sb->s_flags & MS_RDONLY) sb->s_flags |= MS_RDONLY; |