lkml.org 
[lkml]   [2020]   [Nov]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v6 5/8] IMA: extend policy to add data sources as a critical data measurement constraint
    Date
    System administrators should be able to limit which kernel subsystems
    they want to measure the critical data for. To enable that, an IMA policy
    condition to choose specific kernel subsystems is needed. This policy
    condition would constrain the measurement of the critical data to the
    given kernel subsystems.

    Add a new IMA policy condition - "data_sources:=" to the IMA func
    CRITICAL_DATA to allow measurement of various kernel subsystems. This
    policy condition would enable the system administrators to restrict the
    measurement to the subsystems listed in "data_sources:=".

    Limit the measurement to the subsystems that are specified in the IMA
    policy - CRITICAL_DATA+"data_sources:=". If "data_sources:=" is not
    provided with the func CRITICAL_DATA, the data from all the
    supported kernel subsystems is measured.

    Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
    ---
    Documentation/ABI/testing/ima_policy | 4 ++++
    security/integrity/ima/ima_policy.c | 27 ++++++++++++++++++++++++++-
    2 files changed, 30 insertions(+), 1 deletion(-)

    diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
    index 6ec7daa87cba..ee60442a41cd 100644
    --- a/Documentation/ABI/testing/ima_policy
    +++ b/Documentation/ABI/testing/ima_policy
    @@ -52,6 +52,10 @@ Description:
    template:= name of a defined IMA template type
    (eg, ima-ng). Only valid when action is "measure".
    pcr:= decimal value
    + data_sources:= list of kernel subsystems that contain
    + kernel in-memory data critical to the integrity of the kernel.
    + Only valid when action is "measure" and func is
    + CRITICAL_DATA.

    default policy:
    # PROC_SUPER_MAGIC
    diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
    index 583be7674f3e..c9e52dab0638 100644
    --- a/security/integrity/ima/ima_policy.c
    +++ b/security/integrity/ima/ima_policy.c
    @@ -934,7 +934,7 @@ enum {
    Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
    Opt_appraise_type, Opt_appraise_flag,
    Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
    - Opt_err
    + Opt_data_sources, Opt_err
    };

    static const match_table_t policy_tokens = {
    @@ -971,6 +971,7 @@ static const match_table_t policy_tokens = {
    {Opt_pcr, "pcr=%s"},
    {Opt_template, "template=%s"},
    {Opt_keyrings, "keyrings=%s"},
    + {Opt_data_sources, "data_sources=%s"},
    {Opt_err, NULL}
    };

    @@ -1350,6 +1351,24 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)

    entry->flags |= IMA_KEYRINGS;
    break;
    + case Opt_data_sources:
    + ima_log_string(ab, "data_sources",
    + args[0].from);
    +
    + if (entry->data_sources) {
    + result = -EINVAL;
    + break;
    + }
    +
    + entry->data_sources = ima_alloc_rule_opt_list(args);
    + if (IS_ERR(entry->data_sources)) {
    + result = PTR_ERR(entry->data_sources);
    + entry->data_sources = NULL;
    + break;
    + }
    +
    + entry->flags |= IMA_DATA_SOURCES;
    + break;
    case Opt_fsuuid:
    ima_log_string(ab, "fsuuid", args[0].from);

    @@ -1730,6 +1749,12 @@ int ima_policy_show(struct seq_file *m, void *v)
    seq_puts(m, " ");
    }

    + if (entry->flags & IMA_DATA_SOURCES) {
    + seq_puts(m, "data_sources=");
    + ima_show_rule_opt_list(m, entry->data_sources);
    + seq_puts(m, " ");
    + }
    +
    if (entry->flags & IMA_PCR) {
    snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
    seq_printf(m, pt(Opt_pcr), tbuf);
    --
    2.17.1
    \
     
     \ /
      Last update: 2020-11-20 00:28    [W:2.793 / U:0.244 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site