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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EE69D2FFEC for ; Fri, 18 Oct 2024 11:23:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 78B916B0082; Fri, 18 Oct 2024 07:23:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 73B956B0083; Fri, 18 Oct 2024 07:23:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 602E96B0085; Fri, 18 Oct 2024 07:23:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 405AB6B0082 for ; Fri, 18 Oct 2024 07:23:09 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id BC8081406D4 for ; Fri, 18 Oct 2024 11:22:55 +0000 (UTC) X-FDA: 82686486330.14.B2C6996 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by imf29.hostedemail.com (Postfix) with ESMTP id 2C0B3120005 for ; Fri, 18 Oct 2024 11:22:47 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf29.hostedemail.com: domain of roberto.sassu@huaweicloud.com designates 14.137.139.23 as permitted sender) smtp.mailfrom=roberto.sassu@huaweicloud.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1729250467; a=rsa-sha256; cv=none; b=KwIdD6w0NIeUomiUqsvMXbnN8Orz1bZ1Qie95ZVqMXUG0iL2/dpP+3Mcx4mSF8BGW1lvGh 0SaU04fWbNR7xU4qrt15Nvkn1/JJxwzKMA2g79q9RB23ZXs+BgFJML6YxJJ1yrsUGtqnjl Tk7VVE/t/oQMShDp4Aii9B0W0kbFCWo= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf29.hostedemail.com: domain of roberto.sassu@huaweicloud.com designates 14.137.139.23 as permitted sender) smtp.mailfrom=roberto.sassu@huaweicloud.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1729250467; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QMwMSAj+++Ro1MxkiFVXVy3DO+rFL2/9uJK2LYLXFQg=; b=qQYhKThfDyK0axj+o6Q7MzsguQiX7W3rQuIX3rjj9u1xToZZkmafUHJnBluy6iYT4hMHHs dVMRuBdXhMwChSCaTQeUh/kGQ0Pl/K7wRyGiRiT1OvGriUUJ8TPQMIuihgvt+zE6bMCRDA KkPcQDHWEkMS8Xl4EX0NUecdRkkpN74= Received: from mail.maildlp.com (unknown [172.18.186.51]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4XVMHQ1C8pz9v7Hk for ; Fri, 18 Oct 2024 19:02:42 +0800 (CST) Received: from mail02.huawei.com (unknown [7.182.16.47]) by mail.maildlp.com (Postfix) with ESMTP id 284FF1404DA for ; Fri, 18 Oct 2024 19:22:51 +0800 (CST) Received: from [127.0.0.1] (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwDHWDD+RBJnJOwWAw--.51604S2; Fri, 18 Oct 2024 12:22:50 +0100 (CET) Message-ID: Subject: Re: [PATCH 1/3] ima: Remove inode lock From: Roberto Sassu To: "Kirill A. Shutemov" , Lorenzo Stoakes Cc: 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 13:22:35 +0200 In-Reply-To: References: <20241008165732.2603647-1-roberto.sassu@huaweicloud.com> <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 MIME-Version: 1.0 X-CM-TRANSID:LxC2BwDHWDD+RBJnJOwWAw--.51604S2 X-Coremail-Antispam: 1UD129KBjvJXoWxuF13JFWrJw1fuF43Jw4Utwb_yoW5CFyfpr yrJ3WqgFWYqF1xJrn2q3Z0gFn8t34UKFy7WrWrXry8AwnFqF13Cr4rGFy5urs8Ar1kAFyr ZF4UCFZIkay7JFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 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/1tbiAgAABGcRxH8HrQAEsl X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 2C0B3120005 X-Stat-Signature: 5pcmn3zmnhbfa7jmix5wwy41gcky1kb1 X-Rspam-User: X-HE-Tag: 1729250567-114410 X-HE-Meta: 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 Lwtt3VD9 UNVbm5DYtXvSWDvHM+REtE6u5VWyLWSueDBCib82PdLcY0IxxrsW6LJPmAKNHZin108g0GrFrgCKnhmFXH3kSlErqJz3alB9G/rg4IaWfjIwFMeCZwBbGcfbkZ4uC2j6LQ/rDkALZqup5LfPVDqCJTVs8OA33bme1Z7MR+doFfGjN4ezpKlvQHcgaCVH+KWS1IQhl X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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 move > > > > 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 lon= g, 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 advis= ed. > >=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: Thanks a lot! Let's wait a bit until the others have a chance to comment. Meanwhile, I will test it. Do you want me to do the final patch, or will you be proposing it? Roberto > diff --git a/mm/mmap.c b/mm/mmap.c > index dd4b35a25aeb..541787d526b6 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -1646,14 +1646,41 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, = start, unsigned long, size, > if (pgoff + (size >> PAGE_SHIFT) < pgoff) > return ret; > =20 > - if (mmap_write_lock_killable(mm)) > + if (mmap_read_lock_killable(mm)) > return -EINTR; > =20 > vma =3D vma_lookup(mm, start); > =20 > + 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(file, prot, flags); > + if (ret) { > + fput(file); > + return ret; > + } > + > + ret =3D -EINVAL; > + > + if (mmap_write_lock_killable(mm)) { > + fput(file); > + return -EINTR; > + } > + > + vma =3D vma_lookup(mm, start); > + > if (!vma || !(vma->vm_flags & VM_SHARED)) > goto out; > =20 > + if (vma->vm_file !=3D file) > + goto out; > + > if (start + size > vma->vm_end) { > VMA_ITERATOR(vmi, mm, vma->vm_end); > struct vm_area_struct *next, *prev =3D vma; > @@ -1688,16 +1715,11 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, = start, unsigned long, size, > if (vma->vm_flags & VM_LOCKED) > flags |=3D MAP_LOCKED; > =20 > - file =3D get_file(vma->vm_file); > - ret =3D security_mmap_file(vma->vm_file, prot, flags); > - if (ret) > - goto out_fput; > ret =3D do_mmap(vma->vm_file, start, size, > prot, flags, 0, pgoff, &populate, NULL); > -out_fput: > - fput(file); > out: > mmap_write_unlock(mm); > + fput(file); > if (populate) > mm_populate(ret, populate); > if (!IS_ERR_VALUE(ret))