Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next

7 files changed, 95 insertions, 48 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 0cd50491c0a4..802a3fd9e485 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1292,7 +1292,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         Set number of hash buckets for inode cache.
 
         ima_appraise=   [IMA] appraise integrity measurements
-                        Format: { "off" | "enforce" | "fix" }
+                        Format: { "off" | "enforce" | "fix" | "log" }
                         default: "enforce"
 
         ima_appraise_tcb [IMA]
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 8e4bb883fc13..8ee997dff139 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -43,6 +43,9 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
 #define IMA_TEMPLATE_IMA_NAME "ima"
 #define IMA_TEMPLATE_IMA_FMT "d|n"
 
+/* current content of the policy */
+extern int ima_policy_flag;
+
 /* set during initialization */
 extern int ima_initialized;
 extern int ima_used_chip;
@@ -153,14 +156,16 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
                      int flags);
 void ima_init_policy(void);
 void ima_update_policy(void);
+void ima_update_policy_flag(void);
 ssize_t ima_parse_add_rule(char *);
 void ima_delete_rules(void);
 
 /* Appraise integrity measurements */
 #define IMA_APPRAISE_ENFORCE    0x01
 #define IMA_APPRAISE_FIX        0x02
-#define IMA_APPRAISE_MODULES    0x04
-#define IMA_APPRAISE_FIRMWARE   0x08
+#define IMA_APPRAISE_LOG        0x04
+#define IMA_APPRAISE_MODULES    0x08
+#define IMA_APPRAISE_FIRMWARE   0x10
 
 #ifdef CONFIG_IMA_APPRAISE
 int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 65c41a968cc1..86885979918c 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -179,11 +179,6 @@ int ima_get_action(struct inode *inode, int mask, int function)
         return ima_match_policy(inode, function, mask, flags);
 }
 
-int ima_must_measure(struct inode *inode, int mask, int function)
-{
-        return ima_match_policy(inode, function, mask, IMA_MEASURE);
-}
-
 /*
  * ima_collect_measurement - collect file measurement
  *
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 013ec3f0e42d..922685483bd3 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -23,6 +23,8 @@ static int __init default_appraise_setup(char *str)
 {
         if (strncmp(str, "off", 3) == 0)
                 ima_appraise = 0;
+        else if (strncmp(str, "log", 3) == 0)
+                ima_appraise = IMA_APPRAISE_LOG;
         else if (strncmp(str, "fix", 3) == 0)
                 ima_appraise = IMA_APPRAISE_FIX;
         return 1;
@@ -316,7 +318,7 @@ void ima_inode_post_setattr(struct dentry *dentry)
         struct integrity_iint_cache *iint;
         int must_appraise, rc;
 
-        if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode)
+        if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode)
             || !inode->i_op->removexattr)
                 return;
 
@@ -354,7 +356,7 @@ static void ima_reset_appraise_flags(struct inode *inode, int digsig)
 {
         struct integrity_iint_cache *iint;
 
-        if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode))
+        if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode))
                 return;
 
         iint = integrity_iint_find(inode);
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index e8f9d70a465d..9164fc8cac84 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -43,7 +43,7 @@ int ima_used_chip;
  * a different value.) Violations add a zero entry to the measurement
  * list and extend the aggregate PCR value with ff...ff's.
  */
-static void __init ima_add_boot_aggregate(void)
+static int __init ima_add_boot_aggregate(void)
 {
         static const char op[] = "add_boot_aggregate";
         const char *audit_cause = "ENOMEM";
@@ -72,17 +72,23 @@ static void __init ima_add_boot_aggregate(void)
 
         result = ima_alloc_init_template(iint, NULL, boot_aggregate_name,
                                          NULL, 0, &entry);
-        if (result < 0)
-                return;
+        if (result < 0) {
+                audit_cause = "alloc_entry";
+                goto err_out;
+        }
 
         result = ima_store_template(entry, violation, NULL,
                                     boot_aggregate_name);
-        if (result < 0)
+        if (result < 0) {
                 ima_free_template_entry(entry);
-        return;
+                audit_cause = "store_entry";
+                goto err_out;
+        }
+        return 0;
 err_out:
         integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
                             audit_cause, result, 0);
+        return result;
 }
 
 int __init ima_init(void)
@@ -98,6 +104,10 @@ int __init ima_init(void)
         if (!ima_used_chip)
                 pr_info("No TPM chip found, activating TPM-bypass!\n");
 
+        rc = ima_init_keyring(INTEGRITY_KEYRING_IMA);
+        if (rc)
+                return rc;
+
         rc = ima_init_crypto();
         if (rc)
                 return rc;
@@ -105,7 +115,10 @@ int __init ima_init(void)
         if (rc != 0)
                 return rc;
 
-        ima_add_boot_aggregate();       /* boot aggregate must be first entry */
+        rc = ima_add_boot_aggregate();  /* boot aggregate must be first entry */
+        if (rc != 0)
+                return rc;
+
         ima_init_policy();
 
         return ima_fs_init();
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 673a37e92ba3..62f59eca32d3 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -77,42 +77,39 @@ __setup("ima_hash=", hash_setup);
  *        could result in a file measurement error.
  *
  */
-static void ima_rdwr_violation_check(struct file *file)
+static void ima_rdwr_violation_check(struct file *file,
+                                     struct integrity_iint_cache *iint,
+                                     int must_measure,
+                                     char **pathbuf,
+                                     const char **pathname)
 {
         struct inode *inode = file_inode(file);
         fmode_t mode = file->f_mode;
         bool send_tomtou = false, send_writers = false;
-        char *pathbuf = NULL;
-        const char *pathname;
-
-        if (!S_ISREG(inode->i_mode) || !ima_initialized)
-                return;
 
         if (mode & FMODE_WRITE) {
                 if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
-                        struct integrity_iint_cache *iint;
-                        iint = integrity_iint_find(inode);
+                        if (!iint)
+                                iint = integrity_iint_find(inode);
                         /* IMA_MEASURE is set from reader side */
                         if (iint && (iint->flags & IMA_MEASURE))
                                 send_tomtou = true;
                 }
         } else {
-                if ((atomic_read(&inode->i_writecount) > 0) &&
-                    ima_must_measure(inode, MAY_READ, FILE_CHECK))
+                if ((atomic_read(&inode->i_writecount) > 0) && must_measure)
                         send_writers = true;
         }
 
         if (!send_tomtou && !send_writers)
                 return;
 
-        pathname = ima_d_path(&file->f_path, &pathbuf);
+        *pathname = ima_d_path(&file->f_path, pathbuf);
 
         if (send_tomtou)
-                ima_add_violation(file, pathname, "invalid_pcr", "ToMToU");
+                ima_add_violation(file, *pathname, "invalid_pcr", "ToMToU");
         if (send_writers)
-                ima_add_violation(file, pathname,
+                ima_add_violation(file, *pathname,
                                   "invalid_pcr", "open_writers");
-        kfree(pathbuf);
 }
 
 static void ima_check_last_writer(struct integrity_iint_cache *iint,
@@ -160,15 +157,16 @@ static int process_measurement(struct file *file, int mask, int function,
                                int opened)
 {
         struct inode *inode = file_inode(file);
-        struct integrity_iint_cache *iint;
+        struct integrity_iint_cache *iint = NULL;
         struct ima_template_desc *template_desc;
         char *pathbuf = NULL;
         const char *pathname = NULL;
         int rc = -ENOMEM, action, must_appraise;
         struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL;
         int xattr_len = 0;
+        bool violation_check;
 
-        if (!ima_initialized || !S_ISREG(inode->i_mode))
+        if (!ima_policy_flag || !S_ISREG(inode->i_mode))
                 return 0;
 
         /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
@@ -176,7 +174,9 @@ static int process_measurement(struct file *file, int mask, int function,
          * Included is the appraise submask.
          */
         action = ima_get_action(inode, mask, function);
-        if (!action)
+        violation_check = ((function == FILE_CHECK || function == MMAP_CHECK) &&
+                           (ima_policy_flag & IMA_MEASURE));
+        if (!action && !violation_check)
                 return 0;
 
         must_appraise = action & IMA_APPRAISE;
@@ -187,9 +187,20 @@ static int process_measurement(struct file *file, int mask, int function,
 
         mutex_lock(&inode->i_mutex);
 
-        iint = integrity_inode_get(inode);
-        if (!iint)
-                goto out;
+        if (action) {
+                iint = integrity_inode_get(inode);
+                if (!iint)
+                        goto out;
+        }
+
+        if (violation_check) {
+                ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
+                                         &pathbuf, &pathname);
+                if (!action) {
+                        rc = 0;
+                        goto out_free;
+                }
+        }
 
         /* Determine if already appraised/measured based on bitmask
          * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
@@ -218,7 +229,8 @@ static int process_measurement(struct file *file, int mask, int function,
                 goto out_digsig;
         }
 
-        pathname = ima_d_path(&file->f_path, &pathbuf);
+        if (!pathname)  /* ima_rdwr_violation possibly pre-fetched */
+                pathname = ima_d_path(&file->f_path, &pathbuf);
 
         if (action & IMA_MEASURE)
                 ima_store_measurement(iint, file, pathname,
@@ -228,13 +240,15 @@ static int process_measurement(struct file *file, int mask, int function,
                                               xattr_value, xattr_len, opened);
         if (action & IMA_AUDIT)
                 ima_audit_measurement(iint, pathname);
-        kfree(pathbuf);
+
 out_digsig:
         if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
                 rc = -EACCES;
+        kfree(xattr_value);
+out_free:
+        kfree(pathbuf);
 out:
         mutex_unlock(&inode->i_mutex);
-        kfree(xattr_value);
         if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE))
                 return -EACCES;
         return 0;
@@ -288,7 +302,6 @@ int ima_bprm_check(struct linux_binprm *bprm)
  */
 int ima_file_check(struct file *file, int mask, int opened)
 {
-        ima_rdwr_violation_check(file);
         return process_measurement(file,
                                    mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
                                    FILE_CHECK, opened);
@@ -334,14 +347,10 @@ static int __init init_ima(void)
 
         hash_setup(CONFIG_IMA_DEFAULT_HASH);
         error = ima_init();
-        if (error)
-                goto out;
-
-        error = ima_init_keyring(INTEGRITY_KEYRING_IMA);
-        if (error)
-                goto out;
-        ima_initialized = 1;
-out:
+        if (!error) {
+                ima_initialized = 1;
+                ima_update_policy_flag();
+        }
         return error;
 }
 
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 07099a8bc283..cdc620b2152f 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -35,6 +35,8 @@
 #define DONT_APPRAISE   0x0008
 #define AUDIT           0x0040
 
+int ima_policy_flag;
+
 #define MAX_LSM_RULES 6
 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
         LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
@@ -295,6 +297,26 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
         return action;
 }
 
+/*
+ * Initialize the ima_policy_flag variable based on the currently
+ * loaded policy.  Based on this flag, the decision to short circuit
+ * out of a function or not call the function in the first place
+ * can be made earlier.
+ */
+void ima_update_policy_flag(void)
+{
+        struct ima_rule_entry *entry;
+
+        ima_policy_flag = 0;
+        list_for_each_entry(entry, ima_rules, list) {
+                if (entry->action & IMA_DO_MASK)
+                        ima_policy_flag |= entry->action;
+        }
+
+        if (!ima_appraise)
+                ima_policy_flag &= ~IMA_APPRAISE;
+}
+
 /**
  * ima_init_policy - initialize the default measure rules.
  *
@@ -341,6 +363,7 @@ void ima_update_policy(void)
 
         if (ima_rules == &ima_default_rules) {
                 ima_rules = &ima_policy_rules;
+                ima_update_policy_flag();
                 cause = "complete";
                 result = 0;
         }