ima: do not measure or appraise the NSFS filesystem

Include don't appraise or measure rules for the NSFS filesystem
in the builtin ima_tcb and ima_appraise_tcb policies.

Changelog:
- Update documentation

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 3.19

2 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index 232e174aa5de..8ae3f57090d4 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -65,6 +65,9 @@ Description:
                         # CGROUP_SUPER_MAGIC
                         dont_measure fsmagic=0x27e0eb
                         dont_appraise fsmagic=0x27e0eb
+                        # NSFS_MAGIC
+                        dont_measure fsmagic=0x6e736673
+                        dont_appraise fsmagic=0x6e736673
 
                         measure func=BPRM_CHECK
                         measure func=FILE_MMAP mask=MAY_EXEC
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index e4244fc43cf1..f2421f7fa3c8 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -81,6 +81,7 @@ static struct ima_rule_entry default_rules[] = {
         {.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
         {.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC,
          .flags = IMA_FSMAGIC},
+        {.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
         {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
          .flags = IMA_FUNC | IMA_MASK},
         {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
@@ -101,6 +102,7 @@ static struct ima_rule_entry default_appraise_rules[] = {
         {.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
         {.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
         {.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
+        {.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
         {.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 #ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT
         {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .flags = IMA_FOWNER},