From: "Luis R. Rodriguez" <mcgrof@kernel.org>
To: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
"Luis R . Rodriguez" <mcgrof@kernel.org>,
Eric Biederman <ebiederm@xmission.com>,
kexec@lists.infradead.org, Andres Rodriguez <andresx7@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Matthew Garrett <mjg59@google.com>
Subject: Re: [PATCH v4 5/8] ima: based on policy require signed firmware (sysfs fallback)
Date: Fri, 1 Jun 2018 20:21:07 +0200 [thread overview]
Message-ID: <20180601182107.GO4511@wotan.suse.de> (raw)
In-Reply-To: <1527616920-5415-6-git-send-email-zohar@linux.vnet.ibm.com>
On Tue, May 29, 2018 at 02:01:57PM -0400, Mimi Zohar wrote:
> Luis, is the security_kernel_post_read_file LSM hook in
> firmware_loading_store() still needed after this patch? Should it be
> calling security_kernel_load_data() instead?
That's up to Kees to decide as he added that hook, and knows
what LSMs may be doing with it. From my perspective it is confusing
to have that hook there so I think it could be removed now.
Kees?
Luis
>
> ---
>
> With an IMA policy requiring signed firmware, this patch prevents
> the sysfs fallback method of loading firmware.
>
> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
> Cc: Luis R. Rodriguez <mcgrof@suse.com>
> Cc: David Howells <dhowells@redhat.com>
> Cc: Matthew Garrett <mjg59@google.com>
> ---
> security/integrity/ima/ima_main.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index a565d46084c2..4a87f78098c8 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -475,8 +475,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>
> if (!file && read_id == READING_FIRMWARE) {
> if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
> - (ima_appraise & IMA_APPRAISE_ENFORCE))
> + (ima_appraise & IMA_APPRAISE_ENFORCE)) {
> + pr_err("Prevent firmware loading_store.\n");
> return -EACCES; /* INTEGRITY_UNKNOWN */
> + }
> return 0;
> }
>
> @@ -520,6 +522,12 @@ int ima_load_data(enum kernel_load_data_id id)
> pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
> return -EACCES; /* INTEGRITY_UNKNOWN */
> }
> + break;
> + case LOADING_FIRMWARE:
> + if (ima_appraise & IMA_APPRAISE_FIRMWARE) {
> + pr_err("Prevent firmware sysfs fallback loading.\n");
> + return -EACCES; /* INTEGRITY_UNKNOWN */
> + }
> default:
> break;
> }
> --
> 2.7.5
>
>
--
Do not panic
next prev parent reply other threads:[~2018-06-01 18:21 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-29 18:01 [PATCH v4 0/8] kexec/firmware: support system wide policy requiring signatures Mimi Zohar
2018-05-29 18:01 ` [PATCH v4 1/8] security: define new LSM hook named security_kernel_load_data Mimi Zohar
2018-06-04 19:59 ` Serge E. Hallyn
2018-05-29 18:01 ` [PATCH v4 2/8] kexec: add call to LSM hook in original kexec_load syscall Mimi Zohar
2018-06-04 20:00 ` Serge E. Hallyn
2018-05-29 18:01 ` [PATCH v4 3/8] ima: based on policy require signed kexec kernel images Mimi Zohar
2018-05-29 18:01 ` [PATCH v4 4/8] firmware: add call to LSM hook before firmware sysfs fallback Mimi Zohar
2018-06-01 18:19 ` Luis R. Rodriguez
2018-05-29 18:01 ` [PATCH v4 5/8] ima: based on policy require signed firmware (sysfs fallback) Mimi Zohar
2018-06-01 18:21 ` Luis R. Rodriguez [this message]
2018-06-01 22:39 ` Mimi Zohar
2018-06-01 22:46 ` Luis R. Rodriguez
2018-06-01 23:04 ` Mimi Zohar
2018-05-29 18:01 ` [PATCH v4 6/8] ima: add build time policy Mimi Zohar
2018-05-29 18:01 ` [RFC PATCH v4 7/8] ima: based on policy prevent loading firmware (pre-allocated buffer) Mimi Zohar
2018-06-01 19:15 ` Luis R. Rodriguez
2018-06-01 19:25 ` Luis R. Rodriguez
2018-06-05 22:37 ` Kees Cook
2018-06-06 6:20 ` Ard Biesheuvel
2018-06-06 22:06 ` Luis R. Rodriguez
2018-05-29 18:02 ` [PATCH v4 8/8] module: replace the existing LSM hook in init_module Mimi Zohar
2018-05-29 22:39 ` Paul Moore
2018-05-29 23:14 ` Mimi Zohar
2018-05-30 21:00 ` Paul Moore
2018-05-31 15:23 ` [PATCH v4a " Mimi Zohar
2018-06-01 22:28 ` Paul Moore
2018-06-04 9:19 ` Jessica Yu
2018-06-05 19:45 ` Kees Cook
2018-06-05 21:35 ` Mimi Zohar
2018-06-05 22:26 ` Kees Cook
2018-06-05 22:40 ` Mimi Zohar
2018-05-29 23:25 ` [PATCH v4 " Mimi Zohar
2018-05-30 2:25 ` Eric W. Biederman
2018-05-30 21:09 ` Paul Moore
2018-06-04 14:03 ` [PATCH v4 0/8] kexec/firmware: support system wide policy requiring signatures Mimi Zohar
2018-06-04 19:32 ` Serge E. Hallyn
2018-06-04 19:53 ` Mimi Zohar
2018-06-04 22:03 ` Kees Cook
2018-06-05 4:09 ` Serge E. Hallyn
2018-06-05 12:19 ` Kees Cook
2018-06-05 13:25 ` Serge E. Hallyn
2018-06-05 13:43 ` Kees Cook
2018-06-05 14:05 ` Mimi Zohar
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