Re: [RFC][PATCH 8/9] ima: include tmpfs in ima_appraise_tcb policy

Josh Boyer
2015-01-08T13:53:46Z

On Wed, Jan 7, 2015 at 3:52 PM, Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
> Now that the rootfs includes extended attributes, don't
> automatically exclude tmpfs file systems from being appraised.
>
> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
> ---
> security/integrity/evm/evm_main.c | 1 +
> security/integrity/ima/ima_policy.c | 2 ++
> 2 files changed, 3 insertions(+)
>
> diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
> index 9c71af7..e942e63 100644
> --- a/security/integrity/evm/evm_main.c
> +++ b/security/integrity/evm/evm_main.c
> @@ -19,6 +19,7 @@
> #include <linux/module.h>
> #include <linux/crypto.h>
> #include <linux/audit.h>
> +#include <linux/magic.h>
> #include <linux/xattr.h>
> #include <linux/integrity.h>
> #include <linux/evm.h>
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index d1eefb9..7267eac 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -93,7 +93,9 @@ static struct ima_rule_entry default_appraise_rules[] = {
> {.action = DONT_APPRAISE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
> {.action = DONT_APPRAISE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
> {.action = DONT_APPRAISE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
> +#ifndef CONFIG_IMA_LOAD_X509
> {.action = DONT_APPRAISE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
> +#endif

The commit log makes it sound like tmpfs should be appraised
unconditionally, but you only have it being appraised if IMA_LOAD_X509
is set. Which is correct (and why isn't it based on whether
CONFIG_IMA_APPRAISE is set)?

Also, what happens if someone creates an initramfs that doesn't
include xattrs and has this option set?

Slightly confusing.

josh