devpts: return NULL pts 'priv' entry for non-devpts nodes

In commit 8ead9dd ("devpts: more pty driver interface cleanups") I made devpts_get_priv() just return the dentry->fs_data directly. And because I thought it wouldn't happen, I added a warning if you ever saw a pts node that wasn't on devpts. And no, that warning never triggered under any actual real use, but you can trigger it by creating nonsensical pts nodes by hand. So just revert the warning, and make devpts_get_priv() return NULL for that case like it used to. Reported-by: Dmitry Vyukov <[email protected]> Cc: [email protected] # 4.6+ Cc: Eric W Biederman" <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
ambv · Sep 3, 2016 · 3e42394 · 3e42394
1 parent 0141af1
commit 3e42394
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
@@ -585,7 +585,8 @@ struct dentry *devpts_pty_new(struct pts_fs_info *fsi, int index, void *priv)
  */
 void *devpts_get_priv(struct dentry *dentry)
 {
-	WARN_ON_ONCE(dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC);
+	if (dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC)
+		return NULL;
 	return dentry->d_fsdata;
 }