From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout13.his.huawei.com (frasgout13.his.huawei.com [14.137.139.46]) (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 8CCC218EAB; Fri, 18 Oct 2024 11:57:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=14.137.139.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729252630; cv=none; b=gBliIS/F1v2VeCKilEameO6wzRXbViKIlfDteOV0mo88ujHlEKVTJEqsxQxV8RXSZI4rh1s+TWMuiieCk5JZ7QFh65aG/cFpGt7/EVA79J2FIfnc0dCIacjiF2hChqMn7pkW/DxiSAt2KIegIqyrMfAhvet4smJNmP6yWNmdAfE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729252630; c=relaxed/simple; bh=c6ynEdcht14MLuoCIgonB492xPIViEFqyDaGZ8gxT48=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=erQc8iZiVG9y4i72I1ITU2eqKswVvYmfIJFvieOirynZuQk5hYZ1K4kIw1kG1JoH0Qc6zKEMsivCpQsx3icbyjlvPTNeFEtUtB4jsNw2bCCg7MZ2X/GdK4G75d2LHHclfuAIp3+uVRsIpBIQzVKU/kFT8c+N5zelpE3gqh+UfJY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=14.137.139.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.18.186.51]) by frasgout13.his.huawei.com (SkyGuard) with ESMTP id 4XVN2p6hQ1z9v7J5; Fri, 18 Oct 2024 19:36:50 +0800 (CST) Received: from mail02.huawei.com (unknown [7.182.16.47]) by mail.maildlp.com (Postfix) with ESMTP id A83CB1404DA; Fri, 18 Oct 2024 19:56:55 +0800 (CST) Received: from [127.0.0.1] (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwCnNi77TBJngFAXAw--.53565S2; Fri, 18 Oct 2024 12:56:55 +0100 (CET) Message-ID: Subject: Re: [PATCH 1/3] ima: Remove inode lock From: Roberto Sassu To: "Kirill A. Shutemov" Cc: Lorenzo Stoakes , Paul Moore , ebpqwerty472123@gmail.com, kirill.shutemov@linux.intel.com, zohar@linux.ibm.com, dmitry.kasatkin@gmail.com, eric.snowberg@oracle.com, jmorris@namei.org, serge@hallyn.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Roberto Sassu , linux-mm@kvack.org, akpm@linux-foundation.org, vbabka@suse.cz, linux-fsdevel@vger.kernel.org, Liam Howlett , Jann Horn Date: Fri, 18 Oct 2024 13:56:39 +0200 In-Reply-To: References: <7358f12d852964d9209492e337d33b8880234b74.camel@huaweicloud.com> <593282dbc9f48673c8f3b8e0f28e100f34141115.camel@huaweicloud.com> <15bb94a306d3432de55c0a12f29e7ed2b5fa3ba1.camel@huaweicloud.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4-0ubuntu2 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID:LxC2BwCnNi77TBJngFAXAw--.53565S2 X-Coremail-Antispam: 1UD129KBjvJXoW7Cw4UCrykCr1xCrW8Gw47twb_yoW8CFy7pF y8J3WDCF4jvrnrJr1qgw13Krnxt3yUKF1UWryrXryjy3WqvF13Gr4rGFWUu3Z5Jr1kCryr Za1UJa9xCFy5JFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvjb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxV AFwI0_Gr0_Gr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2AF wI0_GFv_Wryl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4 xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5 MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I 0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWU JVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUIa 0PDUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQAABGcRw-kIdAACs3 On Fri, 2024-10-18 at 14:54 +0300, Kirill A. Shutemov wrote: > On Fri, Oct 18, 2024 at 01:22:35PM +0200, Roberto Sassu wrote: > > On Fri, 2024-10-18 at 14:05 +0300, Kirill A. Shutemov wrote: > > > On Fri, Oct 18, 2024 at 12:00:22PM +0100, Lorenzo Stoakes wrote: > > > > + Liam, Jann > > > >=20 > > > > On Fri, Oct 18, 2024 at 01:49:06PM +0300, Kirill A. Shutemov wrote: > > > > > On Fri, Oct 18, 2024 at 11:24:06AM +0200, Roberto Sassu wrote: > > > > > > Probably it is hard, @Kirill would there be any way to safely m= ove > > > > > > security_mmap_file() out of the mmap_lock lock? > > > > >=20 > > > > > What about something like this (untested): > > > > >=20 > > > > > diff --git a/mm/mmap.c b/mm/mmap.c > > > > > index dd4b35a25aeb..03473e77d356 100644 > > > > > --- a/mm/mmap.c > > > > > +++ b/mm/mmap.c > > > > > @@ -1646,6 +1646,26 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned= long, start, unsigned long, size, > > > > > if (pgoff + (size >> PAGE_SHIFT) < pgoff) > > > > > return ret; > > > > >=20 > > > > > + if (mmap_read_lock_killable(mm)) > > > > > + return -EINTR; > > > > > + > > > > > + vma =3D vma_lookup(mm, start); > > > > > + > > > > > + if (!vma || !(vma->vm_flags & VM_SHARED)) { > > > > > + mmap_read_unlock(mm); > > > > > + return -EINVAL; > > > > > + } > > > > > + > > > > > + file =3D get_file(vma->vm_file); > > > > > + > > > > > + mmap_read_unlock(mm); > > > > > + > > > > > + ret =3D security_mmap_file(vma->vm_file, prot, flags); > > > >=20 > > > > Accessing VMA fields without any kind of lock is... very much not a= dvised. > > > >=20 > > > > I'm guessing you meant to say: > > > >=20 > > > > ret =3D security_mmap_file(file, prot, flags); > > > >=20 > > > > Here? :) > > >=20 > > > Sure. My bad. > > >=20 > > > Patch with all fixups: > >=20 > > Thanks a lot! Let's wait a bit until the others have a chance to > > comment. Meanwhile, I will test it. > >=20 > > Do you want me to do the final patch, or will you be proposing it? >=20 > You can post it if it works: >=20 > Signed-off-by: Kirill A. Shutemov Thanks! Ok. Roberto