From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from s3.sipsolutions.net ([144.76.63.242]:48742 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752597AbeENMNu (ORCPT ); Mon, 14 May 2018 08:13:50 -0400 Message-ID: <1526300027.8070.0.camel@sipsolutions.net> (sfid-20180514_141405_188345_F4F0EB32) Subject: Re: WARNING in dev_vprintk_emit From: Johannes Berg To: Eric Biggers , linux-wireless@vger.kernel.org Cc: syzbot , gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Date: Mon, 14 May 2018 14:13:47 +0200 In-Reply-To: <20180513184714.GA677@sol.localdomain> (sfid-20180513_204509_876004_C99B826F) References: <001a113a36724a053a0562f93c05@google.com> <20180513184714.GA677@sol.localdomain> (sfid-20180513_204509_876004_C99B826F) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Sun, 2018-05-13 at 11:47 -0700, Eric Biggers wrote: > The bug is that mac80211_hwsim allows creating device names that are too long, > via HWSIM_CMD_NEW_RADIO. Commit a7cfebcb7594a2 ("cfg80211: limit wiphy names to > 128 bytes") limited them to 128 bytes, but it's not enough because > dev_vprintk_emit() needs the device name plus some other stuff to not exceed 128 > bytes. Here's a reproducer that works on Linus' tree (commit ccda3c4b777), > provided that CONFIG_MAC80211_HWSIM=y. Note that you'll probably need to change > the hardcoded MAC80211_HWSIM generic netlink family ID for it to work. > Johannes, what would you say about limiting the name length to 64 bytes instead? Don't really have any objections - care to send a patch? johannes