From: Linus Torvalds <torvalds@linux-foundation.org>
To: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-fsdevel@vger.kernel.org, jmorris@namei.org,
akpm@linux-foundation.org, eparis@redhat.com,
viro@zeniv.linux.org.uk, Dave Chinner <david@fromorbit.com>,
David Safford <safford@watson.ibm.com>
Subject: Re: [PATCH v1.2 0/5] IMA: making i_readcount a first class inode citizen (reposting)
Date: Sun, 21 Nov 2010 09:56:17 -0800 [thread overview]
Message-ID: <AANLkTikjz3j4j-zLSzagF=wnVE1ROZBGsjtuhGEvB9=n@mail.gmail.com> (raw)
In-Reply-To: <1290345498.2412.38.camel@localhost.localdomain>
On Sun, Nov 21, 2010 at 5:18 AM, Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
>
> IMA (and the proposed EVM/IMA-appraisal patches) detects file change
> based on i_version. When the file is closed, if the file has changed,
> IMA marks the file as needing to be re-measured. Of course this requires
> the filesystem to be mounted with iversion. Don't know if this helps.
If you only do this at close time, I see a _major_ security hole.
The attacker can just write to the file, and keep it open. Ta-daa,
everybody who reads it sees the new contents, but your IMA logic is
oblivious and thinks it doesn't need to be re-measured.
Linus
next prev parent reply other threads:[~2010-11-21 17:56 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-18 23:02 [PATCH v1.2 0/5] IMA: making i_readcount a first class inode citizen (reposting) Mimi Zohar
2010-11-18 23:02 ` [PATCH v1.2 1/5] IMA: convert i_readcount to atomic Mimi Zohar
2010-11-18 23:02 ` [PATCH v1.2 2/5] IMA: define readcount functions Mimi Zohar
2010-11-18 23:03 ` [PATCH v1.2 3/5] IMA: maintain i_readcount in the VFS layer Mimi Zohar
2010-11-18 23:03 ` [PATCH v1.2 4/5] IMA: remove IMA imbalance checking Mimi Zohar
2010-11-18 23:03 ` [PATCH v1.2 5/5] IMA: making i_readcount a first class inode citizen Mimi Zohar
2010-11-18 23:31 ` [PATCH v1.2 0/5] IMA: making i_readcount a first class inode citizen (reposting) Linus Torvalds
2010-11-19 17:50 ` J. Bruce Fields
2010-11-19 17:56 ` J. Bruce Fields
2010-11-21 13:18 ` Mimi Zohar
2010-11-21 17:56 ` Linus Torvalds [this message]
2010-11-21 21:33 ` Mimi Zohar
2010-11-22 13:33 ` David Safford
2010-11-21 21:37 ` J. Bruce Fields
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