[Linux-ima-devel] [PATCH v6 03/10] ima: permit duplicate measurement list entries

Dmitry Kasatkin dmitry.kasatkin at gmail.com
Tue Nov 8 11:47:42 PST 2016


On Fri, Oct 21, 2016 at 5:44 AM, Thiago Jung Bauermann
<bauerman at linux.vnet.ibm.com> wrote:
> From: Mimi Zohar <zohar at linux.vnet.ibm.com>
>
> Measurements carried across kexec need to be added to the IMA
> measurement list, but should not prevent measurements of the newly
> booted kernel from being added to the measurement list. This patch
> adds support for allowing duplicate measurements.
>
> The "boot_aggregate" measurement entry is the delimiter between soft
> boots.
>
> Signed-off-by: Mimi Zohar <zohar at linux.vnet.ibm.com>
> ---
>  security/integrity/ima/ima_queue.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
> index 4b1bb7787839..12d1b040bca9 100644
> --- a/security/integrity/ima/ima_queue.c
> +++ b/security/integrity/ima/ima_queue.c
> @@ -65,11 +65,12 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value,
>  }
>
>  /* ima_add_template_entry helper function:
> - * - Add template entry to measurement list and hash table.
> + * - Add template entry to the measurement list and hash table, for
> + *   all entries except those carried across kexec.
>   *
>   * (Called with ima_extend_list_mutex held.)
>   */
> -static int ima_add_digest_entry(struct ima_template_entry *entry)
> +static int ima_add_digest_entry(struct ima_template_entry *entry, int flags)
>  {
>         struct ima_queue_entry *qe;
>         unsigned int key;
> @@ -85,8 +86,10 @@ static int ima_add_digest_entry(struct ima_template_entry *entry)
>         list_add_tail_rcu(&qe->later, &ima_measurements);
>
>         atomic_long_inc(&ima_htable.len);
> -       key = ima_hash_key(entry->digest);
> -       hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
> +       if (flags) {

It looks lile "bool", not flags in fact.


> +               key = ima_hash_key(entry->digest);
> +               hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
> +       }
>         return 0;
>  }
>
> @@ -126,7 +129,7 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
>                 }
>         }
>
> -       result = ima_add_digest_entry(entry);
> +       result = ima_add_digest_entry(entry, 1);
>         if (result < 0) {
>                 audit_cause = "ENOMEM";
>                 audit_info = 0;
> @@ -155,7 +158,7 @@ int ima_restore_measurement_entry(struct ima_template_entry *entry)
>         int result = 0;
>
>         mutex_lock(&ima_extend_list_mutex);
> -       result = ima_add_digest_entry(entry);
> +       result = ima_add_digest_entry(entry, 0);
>         mutex_unlock(&ima_extend_list_mutex);
>         return result;
>  }
> --
> 2.7.4
>
>
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-- 
Thanks,
Dmitry



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