diff options
| -rw-r--r-- | fs/overlayfs/file.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 1860e220c82d..0f83c8dfec46 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -40,10 +40,22 @@ static struct file *ovl_open_realfile(const struct file *file, struct file *realfile; const struct cred *old_cred; int flags = file->f_flags | O_NOATIME | FMODE_NONOTIFY; + int acc_mode = ACC_MODE(flags); + int err; + + if (flags & O_APPEND) + acc_mode |= MAY_APPEND; old_cred = ovl_override_creds(inode->i_sb); - realfile = open_with_fake_path(&file->f_path, flags, realinode, - current_cred()); + err = inode_permission(realinode, MAY_OPEN | acc_mode); + if (err) { + realfile = ERR_PTR(err); + } else if (!inode_owner_or_capable(realinode)) { + realfile = ERR_PTR(-EPERM); + } else { + realfile = open_with_fake_path(&file->f_path, flags, realinode, + current_cred()); + } revert_creds(old_cred); pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n", |