From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0EE08145A1D for ; Thu, 16 May 2024 13:58:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=18.9.28.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715867910; cv=none; b=lUt+sCvfXnLUcgFI78AITiJf31RUnnIRAcQEyG1ibaPLtPuTtE2/9UQJhIHAXSdfd3g3K1/AUG4AWDnbk3O9HcD+S1S2Sw1nQD2bHM+TTXVe3w2dJSzvY35iegPLTzHpax8kXtUqd+onayGA+HYgrd9kCsmRRviaGxWpzKbq/UY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715867910; c=relaxed/simple; bh=iWsDHgqNQ8pgweObYMjLBbN2LKY9Gg1S0d0qZ2RPGF0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pIB6RfC/f0khATTGDFbCI9bEC0Au6zq9blWARyxxdxYvOEsbr+iu2cBhr70txyVrB3iCy+nCdSUx6kqw94zT0cCrtX4h4asJgdM9YgCesylAjcT47DTBW1wbpHllTRgROgAZ0FL+7BXtMQmgpA8iFPyx25n69YuqOZxUqOzf7G8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu; spf=pass smtp.mailfrom=mit.edu; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b=bDAflBKR; arc=none smtp.client-ip=18.9.28.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mit.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b="bDAflBKR" Received: from macsyma.thunk.org ([50.204.89.32]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 44GDwLJd030699 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 May 2024 09:58:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1715867903; bh=xJIoxjlC8jU+siHznDQ1IUuhqn4B1CX0fXIalXOZzeA=; h=Date:From:Subject:Message-ID:MIME-Version:Content-Type; b=bDAflBKR43ruQP4gVpuCQKJ71lKCvrUcjJuwDIGCknOThKSdRgqcnqjgK1xtbG6Ju egnhhWjSMmAWEfzBLgyh5cPfz3LqmvMNunCBVjA7o29uwntU1JPKwYP8JEPNi4f9bx tqqdd7VP8hXK9LnGhVJbv5CguWr16izbc0QRzzjz5l90ZMS41nONTPdjzaB0ad6kgM 7BgTjr07c8kG49LKmtG2RQLlSxCOnYwdZ47nQ0a6bzzV1HY/2ABXxd6OjdOwc69POi QIvc4SQyndJcbCXLvgLb9Kwmep6baOi5G4ml6BUhDO7bvnKehqKVpfCPmJSvkeh0Do 0kjTsD79zupgA== Received: by macsyma.thunk.org (Postfix, from userid 15806) id 29E1E3407A1; Thu, 16 May 2024 07:58:21 -0600 (MDT) Date: Thu, 16 May 2024 07:58:21 -0600 From: "Theodore Ts'o" To: Shuangpeng Bai Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller@googlegroups.com Subject: Re: KASAN: use-after-free in ext4_find_extent in v6.9 Message-ID: <20240516135821.GA272071@mit.edu> References: <5B9F0C1F-C804-4A9C-8597-4E1A7D16B983@gmail.com> <20240515224932.GA202157@mit.edu> <2184C9DB-DDC2-484B-A1B2-A1E312B62D54@gmail.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2184C9DB-DDC2-484B-A1B2-A1E312B62D54@gmail.com> On Wed, May 15, 2024 at 08:33:33PM -0400, Shuangpeng Bai wrote: > > You are right. I disabled CONFIG_BLK_DEV_WRITE_MOUNTED and found > this bug can not be triggered anymore. > > I am wondering if there is any suggested way for me to check whether > a bug is reproduced under a reasonable environment (such as > compiling config) or not? If so, that would be very helpful. As I mentioned, the upstream syzkaller always forces the CONFIG_BLK_DEV_WRITE_MOUNTED to be disabled. That's the best way to check whether the bug is reproducible under a reasonable environment, and to do it in an automated way. Cheers, - Ted