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 EC885C678D5 for ; Tue, 7 Mar 2023 22:07:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230461AbjCGWH1 (ORCPT ); Tue, 7 Mar 2023 17:07:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231342AbjCGWHX (ORCPT ); Tue, 7 Mar 2023 17:07:23 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C56B2ADC35; Tue, 7 Mar 2023 14:07:14 -0800 (PST) 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 6AD4C6158C; Tue, 7 Mar 2023 22:07:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAA5EC433EF; Tue, 7 Mar 2023 22:07:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1678226833; bh=vTNT7wf34EPvbnBAgH6TGwQE2d0jRjnSE3JmNfcyQdA=; h=Date:To:From:Subject:From; b=tAsnrYFDcMV6o3Yb/5vhsQRiUehcgf5uIlgIa5nh8lPZKkEiPZZi74OHGIhjcFpLL pSwU+8lSRygSwSVIxATw4ksMpESK5HoD/naCosCyMPGPBCmgkaulc19G5AvZJgmImS EN6am8aEKVcL429qJU/V/TwkCYUuS8b1GqfgZnl0= Date: Tue, 07 Mar 2023 14:07:13 -0800 To: mm-commits@vger.kernel.org, stable@vger.kernel.org, konishi.ryusuke@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: + nilfs2-fix-kernel-infoleak-in-nilfs_ioctl_wrap_copy.patch added to mm-hotfixes-unstable branch Message-Id: <20230307220713.BAA5EC433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: nilfs2: fix kernel-infoleak in nilfs_ioctl_wrap_copy() has been added to the -mm mm-hotfixes-unstable branch. Its filename is nilfs2-fix-kernel-infoleak-in-nilfs_ioctl_wrap_copy.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/nilfs2-fix-kernel-infoleak-in-nilfs_ioctl_wrap_copy.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Ryusuke Konishi Subject: nilfs2: fix kernel-infoleak in nilfs_ioctl_wrap_copy() Date: Tue, 7 Mar 2023 17:55:48 +0900 The ioctl helper function nilfs_ioctl_wrap_copy(), which exchanges a metadata array to/from user space, may copy uninitialized buffer regions to user space memory for read-only ioctl commands NILFS_IOCTL_GET_SUINFO and NILFS_IOCTL_GET_CPINFO. This can occur when the element size of the user space metadata given by the v_size member of the argument nilfs_argv structure is larger than the size of the metadata element (nilfs_suinfo structure or nilfs_cpinfo structure) on the file system side. KMSAN-enabled kernels detect this issue as follows: BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xc0/0x100 lib/usercopy.c:33 instrument_copy_to_user include/linux/instrumented.h:121 [inline] _copy_to_user+0xc0/0x100 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:169 [inline] nilfs_ioctl_wrap_copy+0x6fa/0xc10 fs/nilfs2/ioctl.c:99 nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline] nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290 nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343 __do_compat_sys_ioctl fs/ioctl.c:968 [inline] __se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910 __ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Uninit was created at: __alloc_pages+0x9f6/0xe90 mm/page_alloc.c:5572 alloc_pages+0xab0/0xd80 mm/mempolicy.c:2287 __get_free_pages+0x34/0xc0 mm/page_alloc.c:5599 nilfs_ioctl_wrap_copy+0x223/0xc10 fs/nilfs2/ioctl.c:74 nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline] nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290 nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343 __do_compat_sys_ioctl fs/ioctl.c:968 [inline] __se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910 __ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Bytes 16-127 of 3968 are uninitialized ... This eliminates the leak issue by initializing the page allocated as buffer using get_zeroed_page(). Link: https://lkml.kernel.org/r/20230307085548.6290-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Reported-by: syzbot+132fdd2f1e1805fdc591@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/000000000000a5bd2d05f63f04ae@google.com Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton --- fs/nilfs2/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/nilfs2/ioctl.c~nilfs2-fix-kernel-infoleak-in-nilfs_ioctl_wrap_copy +++ a/fs/nilfs2/ioctl.c @@ -71,7 +71,7 @@ static int nilfs_ioctl_wrap_copy(struct if (argv->v_index > ~(__u64)0 - argv->v_nmembs) return -EINVAL; - buf = (void *)__get_free_pages(GFP_NOFS, 0); + buf = (void *)get_zeroed_page(GFP_NOFS); if (unlikely(!buf)) return -ENOMEM; maxmembs = PAGE_SIZE / argv->v_size; _ Patches currently in -mm which might be from konishi.ryusuke@gmail.com are nilfs2-fix-kernel-infoleak-in-nilfs_ioctl_wrap_copy.patch