linux-kernel - Re: [RFC PATCH v1] ima: verify mprotect change is consistent with mmap policy

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Tue, 5 May 2020 10:52:12 -0700
From:   Lakshmi Ramasubramanian <nramas@...ux.microsoft.com>
To:     Mimi Zohar <zohar@...ux.ibm.com>, linux-integrity@...r.kernel.org
Cc:     Casey Schaufler <casey@...aufler-ca.com>,
        Jann Horn <jannh@...gle.com>,
        Stephen Smalley <stephen.smalley.work@...il.com>,
        Eric Biggers <ebiggers@...nel.org>,
        linux-security-module@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH v1] ima: verify mprotect change is consistent with
 mmap policy

On 5/5/20 10:30 AM, Mimi Zohar wrote:

> Files can be mmap'ed read/write and later changed to execute to circumvent
> IMA's mmap appraise policy rules.  Due to locking issues (mmap semaphore
> would be taken prior to i_mutex), files can not be measured or appraised at
> this point.  Eliminate this integrity gap, by denying the mprotect
> PROT_EXECUTE change, if an mmap appraise policy rule exists.
> 
> On mprotect change success, return 0.  On failure, return -EACESS.
> 
> Signed-off-by: Mimi Zohar <zohar@...ux.ibm.com>
> ---
> Changelog v1:
> - Reverse tests to remove code indentation. (Lakshmi Ramasubramanian)
> - General code cleanup, including adding comments.
> 
>   include/linux/ima.h               |  7 ++++++
>   security/integrity/ima/ima_main.c | 51 +++++++++++++++++++++++++++++++++++++++
>   security/security.c               |  7 +++++-
>   3 files changed, 64 insertions(+), 1 deletion(-)

Reviewed-by: Lakshmi Ramasubramanian <nramas@...ux.microsoft.com>