| Message ID | 22475.1509642717@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 2017-11-02 at 17:11 +0000, David Howells wrote: > I've made the revisions suggested. See the attached patch. It looks good, except for a mistake in the original I patch posted. > --- > commit 721c0994b824b91acd3c412abe55ae41287fc64d > Author: Mimi Zohar <zohar@linux.vnet.ibm.com> > Date: Mon Oct 23 11:59:47 2017 -0400 > > ima: require secure_boot rules in lockdown mode > > Require the "secure_boot" rules, whether or not it is specified > on the boot command line, for both the builtin and custom policies > in secure boot lockdown mode. > > Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> > Signed-off-by: David Howells <dhowells@redhat.com> > > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c > index 95209a5f8595..f64f2be2dc0c 100644 > --- a/security/integrity/ima/ima_policy.c > +++ b/security/integrity/ima/ima_policy.c > @@ -427,14 +427,21 @@ void ima_update_policy_flag(void) > */ > void __init ima_init_policy(void) > { > - int i, measure_entries, appraise_entries, secure_boot_entries; > + int i; > + int measure_entries = 0; > + int appraise_entries = 0; > + int secure_boot_entries = 0; > + bool kernel_locked_down = kernel_is_locked_down(); kernel_is_locked_down() requires a string. Mimi > > /* if !ima_policy set entries = 0 so we load NO default rules */ > - measure_entries = ima_policy ? ARRAY_SIZE(dont_measure_rules) : 0; > - appraise_entries = ima_use_appraise_tcb ? > - ARRAY_SIZE(default_appraise_rules) : 0; > - secure_boot_entries = ima_use_secure_boot ? > - ARRAY_SIZE(secure_boot_rules) : 0; > + if (ima_policy) > + measure_entries = ARRAY_SIZE(dont_measure_rules); > + > + if (ima_use_appraise_tcb) > + appraise_entries = ARRAY_SIZE(default_appraise_rules); > + > + if (ima_use_secure_boot || kernel_locked_down) > + secure_boot_entries = ARRAY_SIZE(secure_boot_rules); > > for (i = 0; i < measure_entries; i++) > list_add_tail(&dont_measure_rules[i].list, &ima_default_rules); > @@ -455,11 +462,23 @@ void __init ima_init_policy(void) > > /* > * Insert the appraise rules requiring file signatures, prior to > - * any other appraise rules. > + * any other appraise rules. In secure boot lock-down mode, also > + * require these appraise rules for custom policies. > */ > - for (i = 0; i < secure_boot_entries; i++) > - list_add_tail(&secure_boot_rules[i].list, > - &ima_default_rules); > + for (i = 0; i < secure_boot_entries; i++) { > + struct ima_rule_entry *entry; > + > + /* Include for builtin policies */ > + list_add_tail(&secure_boot_rules[i].list, &ima_default_rules); > + > + /* Include for custom policies */ > + if (kernel_locked_down) { > + entry = kmemdup(&secure_boot_rules[i], sizeof(*entry), > + GFP_KERNEL); > + if (entry) > + list_add_tail(&entry->list, &ima_policy_rules); > + } > + } > > for (i = 0; i < appraise_entries; i++) { > list_add_tail(&default_appraise_rules[i].list, > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
Mimi Zohar <zohar@linux.vnet.ibm.com> wrote: > > + bool kernel_locked_down = kernel_is_locked_down(); > > kernel_is_locked_down() requires a string. Hmmm... Probably don't want to call kernel_is_locked_down() here as that'll get a message printed saying that you tried to do something that's disallowed. Possibly: ... = __kernel_is_locked_down("", false); Though it might be better to provide a second vector. David
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 95209a5f8595..f64f2be2dc0c 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -427,14 +427,21 @@ void ima_update_policy_flag(void) */ void __init ima_init_policy(void) { - int i, measure_entries, appraise_entries, secure_boot_entries; + int i; + int measure_entries = 0; + int appraise_entries = 0; + int secure_boot_entries = 0; + bool kernel_locked_down = kernel_is_locked_down(); /* if !ima_policy set entries = 0 so we load NO default rules */ - measure_entries = ima_policy ? ARRAY_SIZE(dont_measure_rules) : 0; - appraise_entries = ima_use_appraise_tcb ? - ARRAY_SIZE(default_appraise_rules) : 0; - secure_boot_entries = ima_use_secure_boot ? - ARRAY_SIZE(secure_boot_rules) : 0; + if (ima_policy) + measure_entries = ARRAY_SIZE(dont_measure_rules); + + if (ima_use_appraise_tcb) + appraise_entries = ARRAY_SIZE(default_appraise_rules); + + if (ima_use_secure_boot || kernel_locked_down) + secure_boot_entries = ARRAY_SIZE(secure_boot_rules); for (i = 0; i < measure_entries; i++) list_add_tail(&dont_measure_rules[i].list, &ima_default_rules); @@ -455,11 +462,23 @@ void __init ima_init_policy(void) /* * Insert the appraise rules requiring file signatures, prior to - * any other appraise rules. + * any other appraise rules. In secure boot lock-down mode, also + * require these appraise rules for custom policies. */ - for (i = 0; i < secure_boot_entries; i++) - list_add_tail(&secure_boot_rules[i].list, - &ima_default_rules); + for (i = 0; i < secure_boot_entries; i++) { + struct ima_rule_entry *entry; + + /* Include for builtin policies */ + list_add_tail(&secure_boot_rules[i].list, &ima_default_rules); + + /* Include for custom policies */ + if (kernel_locked_down) { + entry = kmemdup(&secure_boot_rules[i], sizeof(*entry), + GFP_KERNEL); + if (entry) + list_add_tail(&entry->list, &ima_policy_rules); + } + } for (i = 0; i < appraise_entries; i++) { list_add_tail(&default_appraise_rules[i].list,
I've made the revisions suggested. See the attached patch. David --- commit 721c0994b824b91acd3c412abe55ae41287fc64d Author: Mimi Zohar <zohar@linux.vnet.ibm.com> Date: Mon Oct 23 11:59:47 2017 -0400 ima: require secure_boot rules in lockdown mode Require the "secure_boot" rules, whether or not it is specified on the boot command line, for both the builtin and custom policies in secure boot lockdown mode. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com>