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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 0020FC3815B for ; Wed, 15 Apr 2020 15:16:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D03232078B for ; Wed, 15 Apr 2020 15:16:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="PQEZoTss" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393368AbgDOPQq (ORCPT ); Wed, 15 Apr 2020 11:16:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S2393356AbgDOPQm (ORCPT ); Wed, 15 Apr 2020 11:16:42 -0400 Received: from mail-qk1-x742.google.com (mail-qk1-x742.google.com [IPv6:2607:f8b0:4864:20::742]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40C0AC061A0F for ; Wed, 15 Apr 2020 08:16:42 -0700 (PDT) Received: by mail-qk1-x742.google.com with SMTP id j4so17521300qkc.11 for ; Wed, 15 Apr 2020 08:16:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2qQPAGL2IMZ0eMjrwtJCIRCLqfeX6RhiXaeITvmueB4=; b=PQEZoTsslxtO2VG1gZ9IEXJ+x1EGsPSa5w+d4wjTJVgOduX5sEJ6HZoJfJRBbXRsU9 EXHzIHgdRzFaKGGE+fT3peXwkYEIAHFi3cdXG68+ylSdKhZL8gWe9zBXPqhUeWc2cNdF gsEt61yr3z2YAwQghdQbDx6ZcQjhSEnozaayKcy7LJF75jqkrlpPlsnvR009mnmOtVmq rjYjjR2c7Z1XHNg9dZbS7hATI88O0Qk6m97LJX9sd2Ky24Y2RfKkcTujsfHYrgtSzudc op08cFDcPhGoabbs8CyIn+yDkK6oWBZ58w+VvEJ/gPs6yUnaHhv7LTvRu4+UHccln//R Fm6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=2qQPAGL2IMZ0eMjrwtJCIRCLqfeX6RhiXaeITvmueB4=; b=Au2IgUCszhwPR/ABUV6bVa8tDjt8aRnyurs9TF5JqYtHdTCDOptRyzbdQIJcyvNHHm bNLj/VxtW0tcInCVfDt0rPCDzF2cSblv5RbcnOchmcrWnL4oC+/sf5clhsz+t/L0MMJy pj6YPs0Dig1pxUJ0UYgSGt1ANIMJYJ+K44Cbu4ZEbR7Bp5LGq1evGrYRkzI5/BUwZtwq fY9BH5oHdtPQ8o4oxSmwKt/wQeH+ak8acryifhRM4m9ahe8ewyr0YU9zfgU8sGKdtukM MHyxB+pzI8R5nwDpJbBuddHK5SD2eXkjbVtmCLxlhKZSBxRfFkqQZ8Aq59bIxYKZPZGs dUPw== X-Gm-Message-State: AGi0PuZAsMwQkT2Rk9wq5Qj9pxbAshLR+EgDCiBH0X+Kn+QNCbaYgLTw GdUvrEInEz+jCO6Bh7SYlXOinz0XO14Aejltg4U+bw== X-Google-Smtp-Source: APiQypJF3rrWtTJifwbFr2yPhwI9Guj+09QRJ+ZSsnlVpgr82MOSMQpPk7+ZCYHIQZ3xMrt25PXwdxnh13N+LBZi64Q= X-Received: by 2002:a37:8d86:: with SMTP id p128mr27408591qkd.250.1586963800654; Wed, 15 Apr 2020 08:16:40 -0700 (PDT) MIME-Version: 1.0 References: <000000000000cb517b05a32c917b@google.com> In-Reply-To: From: Dmitry Vyukov Date: Wed, 15 Apr 2020 17:16:28 +0200 Message-ID: Subject: Re: WARNING in hwsim_new_radio_nl To: Johannes Berg , syzkaller Cc: syzbot , David Miller , Kalle Valo , LKML , linux-wireless@vger.kernel.org, mathew.j.martineau@linux.intel.com, matthieu.baerts@tessares.net, netdev , Paolo Abeni , syzkaller-bugs Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 14, 2020 at 12:41 PM Johannes Berg wrote: > > Hi syzbot keepers, > > On Mon, 2020-04-13 at 07:05 -0700, syzbot wrote: > > syzbot has bisected this bug to: > > > > commit 01cacb00b35cb62b139f07d5f84bcf0eeda8eff6 > > Author: Paolo Abeni > > Date: Fri Mar 27 21:48:51 2020 +0000 > > > > mptcp: add netlink-based PM > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10225bb3e00000 > > This is, fairly obviously, incorrect. Same with the bisection for > 6693adf1698864d21734, which is really the same underlying problem as > this one (though at a different code site). > > However, it stands out that this was bisected to a commit that adds a > new generic netlink family in both cases. > > This makes sense - the reproducer identifies the family by *number*, but > that number isn't stable, generic netlink families should be identified > by *name*. > > Perhaps somehow syzbot could be taught that, so that the bisection is > stable across kernels with different generic netlink families > registered? > > Alternatively, we _could_ add some kind of stable ID mode, but I'm not > sure we really want to ... since that would mean people start hardcoding > IDs? +syzkaller mailing list Hi Johannes, syzkaller has a pseudo-syscall to map string genetlink family ID to int ID. If that syscall would have been used, then I assume it should have worked. However in this case, it managed to trigger the bug with a plain opaque blob with no knowledge about the blob contents whatsoever. I don't see any realistic way to preserve family ID in this case.