[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <6a98beea4607a9684789e862b4182dfdf3bec8de.camel@linux.ibm.com>
Date: Tue, 31 Jan 2023 19:00:09 -0500
From: Mimi Zohar <zohar@...ux.ibm.com>
To: Roberto Sassu <roberto.sassu@...weicloud.com>,
dmitry.kasatkin@...il.com, jmorris@...ei.org, serge@...lyn.com
Cc: linux-integrity@...r.kernel.org,
linux-security-module@...r.kernel.org,
linux-kernel@...r.kernel.org, stefanb@...ux.ibm.com,
viro@...iv.linux.org.uk, pvorel@...e.cz,
Roberto Sassu <roberto.sassu@...wei.com>
Subject: Re: [PATCH ima-evm-utils v2] Add tests for MMAP_CHECK and
MMAP_CHECK_REQPROT hooks
On Tue, 2023-01-31 at 18:42 +0100, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@...wei.com>
>
> Add tests to ensure that, after applying the kernel patch 'ima: Align
> ima_file_mmap() parameters with mmap_file LSM hook', the MMAP_CHECK hook
> checks the protections applied by the kernel and not those requested by the
> application.
>
> Also ensure that after applying 'ima: Introduce MMAP_CHECK_REQPROT hook',
> the MMAP_CHECK_REQPROT hook checks the protections requested by the
> application.
>
> Test both with the test_mmap application that by default requests the
> PROT_READ protection flag. Its syntax is:
>
> test_mmap <file> <mode>
>
> where mode can be:
> - exec: adds the PROT_EXEC protection flag to mmap()
> - read_implies_exec: calls the personality() system call with
> READ_IMPLIES_EXEC as the first argument before mmap()
> - mprotect: adds the PROT_EXEC protection flag to a memory area in addition
> to PROT_READ
> - exec_on_writable: calls mmap() with PROT_EXEC on a file which has a
> writable mapping
>
> Check the different combinations of hooks/modes and ensure that a
> measurement entry is found in the IMA measurement list only when it is
> expected. No measurement entry should be found when only the PROT_READ
> protection flag is requested or the matching policy rule has the
> MMAP_CHECK_REQPROT hook and the personality() system call was called with
> READ_IMPLIES_EXEC.
>
> mprotect() with PROT_EXEC on an existing memory area protected with
> PROT_READ should be denied (with an appraisal rule), regardless of the MMAP
> hook specified in the policy. The same applies for mmap() with PROT_EXEC on
> a file with a writable mapping.
>
> Signed-off-by: Roberto Sassu <roberto.sassu@...wei.com>
Nice! Including some comments, or at least the test assumption, would
help simplify reviewing the code.
Reviewed-by: Mimi Zohar <zohar@...ux.ibm.com>
Powered by blists - more mailing lists