linux-kernel - Re: [RESEND][PATCH] ima: Set and clear FMODE_CAN_READ in ima_calc_file

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHk-=wjd0RNthZQTLVsnK_d9SFYH0rug2tkezLLB0J-YZzVC+Q@mail.gmail.com>
Date:   Mon, 16 Nov 2020 10:09:28 -0800
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     Mimi Zohar <zohar@...ux.ibm.com>,
        Roberto Sassu <roberto.sassu@...wei.com>,
        "linux-integrity@...r.kernel.org" <linux-integrity@...r.kernel.org>,
        "linux-security-module@...r.kernel.org" 
        <linux-security-module@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Silviu Vlasceanu <Silviu.Vlasceanu@...wei.com>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>,
        "viro@...iv.linux.org.uk" <viro@...iv.linux.org.uk>,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>
Subject: Re: [RESEND][PATCH] ima: Set and clear FMODE_CAN_READ in ima_calc_file_hash()

On Mon, Nov 16, 2020 at 9:41 AM Christoph Hellwig <hch@...radead.org> wrote:
>
> The "issue" with IMA is that it uses security hooks to hook into the
> VFS and then wants to read every file that gets opened on a real file
> system to "measure" the contents vs a hash stashed away somewhere.

Well, but that's easy enough to handle: if the open isn't a read open,
then the old contents don't matter, so you shouldn't bother to measure
the file.

So this literally sounds like a "doctor, doctor, it hurts when I hit
my head with a hammer" situation..

         Linus