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 X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38D01C433ED for ; Fri, 7 May 2021 06:26:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C08961154 for ; Fri, 7 May 2021 06:26:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234136AbhEGG1t (ORCPT ); Fri, 7 May 2021 02:27:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:43028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230380AbhEGG1s (ORCPT ); Fri, 7 May 2021 02:27:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1E20C610FA; Fri, 7 May 2021 06:26:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620368809; bh=26lW/SlE/3tJXeTGnqnhmb7qE4S+ECkvLL6V6VcGy/c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QY/O7ugwDFC6NdsFh2BVxwy0nlopRdBeqyFlCL9G4d5FMH1aoe3c5KPUbucOrobZX An4KwX3zBs3/9NYI9JlzJ8XF3s4jvqH3x4VBNEVdy1sGO9cH+M0J/p2AYfS3yzJ8mQ UE6ocjIkqyiBTw7N3+tIoK5VLMyipFy93ryG6QS3+heoKGeQ9KSV4jatwHFhz3elgm 5Ayat9Y0AaHu6aFQn7ctwKXdGnjgLl7Gqlv5burxcyd5/cJrFTFS5yUgsIRauOZYK/ HJuAwC1cuWCbHpI6D45phnn0k3NQdbY1mTEt98ajudqb88DYelL+RWOzWUxkOkPdG9 lS14JTBbedlNg== Date: Thu, 6 May 2021 23:26:47 -0700 From: Eric Biggers To: Jaegeuk Kim Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH] f2fs: return -EPERM given generic mask Message-ID: References: <20210506191347.1242802-1-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210506191347.1242802-1-jaegeuk@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 06, 2021 at 12:13:47PM -0700, Jaegeuk Kim wrote: > In f2fs_fileattr_set(), > > if (!fa->flags_valid) > mask &= FS_COMMON_FL; > > In this case, we should not allow to set FS_COMPR_FL, instead of BUG_ON. > > /* Flags shared betwen flags/xflags */ > (FS_SYNC_FL | FS_IMMUTABLE_FL | FS_APPEND_FL | \ > FS_NODUMP_FL | FS_NOATIME_FL | FS_DAX_FL | \ > FS_PROJINHERIT_FL) > > Fixes: 4c5b47997521 ("vfs: add fileattr ops") > Signed-off-by: Jaegeuk Kim > --- > fs/f2fs/file.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index e01ce802cf10..38015ef84893 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -1817,7 +1817,9 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask) > struct f2fs_inode_info *fi = F2FS_I(inode); > u32 masked_flags = fi->i_flags & mask; > > - f2fs_bug_on(F2FS_I_SB(inode), (iflags & ~mask)); > + /* mask can be shrunk by flags_valid selector */ > + if (iflags & ~mask) > + return -EPERM; > > /* Is it quota file? Do not allow user to mess with it */ > if (IS_NOQUOTA(inode)) > -- > 2.31.1.607.g51e8a6a459-goog This looks like the wrong fix. AFAICS, 'mask' is the set of inode flags that the specific ioctl (FS_IOC_SETFLAGS or FS_IOC_FSSETXATTR) can potentially modify, while 'iflags' is the new set of inode flags among the set that either ioctl can potentially modify. So this change will stop FS_IOC_FSSETXATTR from working on files that have already flags set which are only modifiable by FS_IOC_SETFLAGS, e.g. the compression flag. I think the correct fix would be to just do something like 'iflags &= mask'. - Eric