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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02248C433EF for ; Mon, 14 Mar 2022 17:03:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241476AbiCNREX (ORCPT ); Mon, 14 Mar 2022 13:04:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235231AbiCNREU (ORCPT ); Mon, 14 Mar 2022 13:04:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B922726C for ; Mon, 14 Mar 2022 10:03:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A97FE60C4C for ; Mon, 14 Mar 2022 17:03:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6DED2C340E9; Mon, 14 Mar 2022 17:03:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647277387; bh=pCwo8DVMuAXtLbgi4FppS9g1hfzWAu2PWvm7U+aZ9w8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=L3VB5nwgpzixKzFTEIUR35ZeWEwR86iqfrlxG4rWe2gYlDs7o65YNwNvTTkPZC4cQ Lhe9nAbR+GmBkjVrE+14GS5GW9w/jnfEhstEnttGgoPn/D6mlzPctqnp/YmrABsya2 mHHog/QafDJbYFpKZ6dMS1EhzWTYTpW99GSpGMoU= Date: Mon, 14 Mar 2022 18:03:03 +0100 From: Greg KH To: Tejun Heo Cc: syzbot , linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] KASAN: use-after-free Read in kernfs_get Message-ID: References: <0000000000006b04e005da2df2f3@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 14, 2022 at 06:05:32AM -1000, Tejun Heo wrote: > On Mon, Mar 14, 2022 at 06:49:19AM -0700, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 09688c0166e7 Linux 5.17-rc8 > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=11b42729700000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=6da459dcfde3b8d0 > > dashboard link: https://syzkaller.appspot.com/bug?extid=97a16334dbd58916f7fb > > compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+97a16334dbd58916f7fb@syzkaller.appspotmail.com > > > > usb 1-1: Direct firmware load for ueagle-atm/adi930.fw failed with error -2 > > usb 1-1: Falling back to sysfs fallback for: ueagle-atm/adi930.fw > > ================================================================== > > BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] > > BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] > > BUG: KASAN: use-after-free in kernfs_get+0x1c/0x90 fs/kernfs/dir.c:496 > > Read of size 4 at addr ffff88801ded39f8 by task kworker/1:2/2510 > > Looks like firmware loading and usb hub removal racing? I'm not sure there's > whole lot we can do from the kernfs side. Greg? Odd. Let me look at it. If syzbot is starting to poke at ATM drivers, wow, lots of issues are going to start falling out... thanks, greg k-h