From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61BBAC32751 for ; Sat, 10 Aug 2019 20:51:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40B1E208C3 for ; Sat, 10 Aug 2019 20:51:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727568AbfHJUvg (ORCPT ); Sat, 10 Aug 2019 16:51:36 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54306 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726670AbfHJUny (ORCPT ); Sat, 10 Aug 2019 16:43:54 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hwYDP-00053i-IA; Sat, 10 Aug 2019 21:43:51 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hwYDM-0003gp-RM; Sat, 10 Aug 2019 21:43:48 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Johannes Berg" , syzbot+4ece1a28b8f4730547c9@syzkaller.appspotmail.com Date: Sat, 10 Aug 2019 21:40:07 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 103/157] mac80211: don't attempt to rename ERR_PTR() debugfs dirs In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.72-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg commit 517879147493a5e1df6b89a50f708f1133fcaddb upstream. We need to dereference the directory to get its parent to be able to rename it, so it's clearly not safe to try to do this with ERR_PTR() pointers. Skip in this case. It seems that this is most likely what was causing the report by syzbot, but I'm not entirely sure as it didn't come with a reproducer this time. Reported-by: syzbot+4ece1a28b8f4730547c9@syzkaller.appspotmail.com Signed-off-by: Johannes Berg Signed-off-by: Ben Hutchings --- net/mac80211/debugfs_netdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/mac80211/debugfs_netdev.c +++ b/net/mac80211/debugfs_netdev.c @@ -735,7 +735,7 @@ void ieee80211_debugfs_rename_netdev(str dir = sdata->vif.debugfs_dir; - if (!dir) + if (IS_ERR_OR_NULL(dir)) return; sprintf(buf, "netdev:%s", sdata->name);