ima: move full pathname resolution to separate function

Define a new function ima_d_path(), which returns the full pathname.
This function will be used further, for example, by the directory
verification code.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

3 files changed, 38 insertions, 31 deletions

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 1385c5c172f7..991844db98d9 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -119,6 +119,7 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
 int ima_store_template(struct ima_template_entry *entry, int violation,
                        struct inode *inode);
 void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show);
+const char *ima_d_path(struct path *path, char **pathbuf);
 
 /* rbtree tree calls to lookup, insert, delete
  * integrity data associated with an inode.
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index fc722b44c416..9382a4c568b2 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -237,3 +237,20 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
 
         iint->flags |= IMA_AUDITED;
 }
+
+const char *ima_d_path(struct path *path, char **pathbuf)
+{
+        char *pathname = NULL;
+
+        /* We will allow 11 spaces for ' (deleted)' to be appended */
+        *pathbuf = kmalloc(PATH_MAX + 11, GFP_KERNEL);
+        if (*pathbuf) {
+                pathname = d_path(path, *pathbuf, PATH_MAX + 11);
+                if (IS_ERR(pathname)) {
+                        kfree(*pathbuf);
+                        *pathbuf = NULL;
+                        pathname = NULL;
+                }
+        }
+        return pathname;
+}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 970693d1a320..d743c9a0a4b4 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -61,7 +61,8 @@ static void ima_rdwr_violation_check(struct file *file)
         fmode_t mode = file->f_mode;
         int must_measure;
         bool send_tomtou = false, send_writers = false;
-        unsigned char *pathname = NULL, *pathbuf = NULL;
+        char *pathbuf = NULL;
+        const char *pathname;
 
         if (!S_ISREG(inode->i_mode) || !ima_initialized)
                 return;
@@ -86,22 +87,15 @@ out:
         if (!send_tomtou && !send_writers)
                 return;
 
-        /* We will allow 11 spaces for ' (deleted)' to be appended */
-        pathbuf = kmalloc(PATH_MAX + 11, GFP_KERNEL);
-        if (pathbuf) {
-                pathname = d_path(&file->f_path, pathbuf, PATH_MAX + 11);
-                if (IS_ERR(pathname))
-                        pathname = NULL;
-                else if (strlen(pathname) > IMA_EVENT_NAME_LEN_MAX)
-                        pathname = NULL;
-        }
+        pathname = ima_d_path(&file->f_path, &pathbuf);
+        if (!pathname || strlen(pathname) > IMA_EVENT_NAME_LEN_MAX)
+                pathname = dentry->d_name.name;
+
         if (send_tomtou)
-                ima_add_violation(inode,
-                                  !pathname ? dentry->d_name.name : pathname,
+                ima_add_violation(inode, pathname,
                                   "invalid_pcr", "ToMToU");
         if (send_writers)
-                ima_add_violation(inode,
-                                  !pathname ? dentry->d_name.name : pathname,
+                ima_add_violation(inode, pathname,
                                   "invalid_pcr", "open_writers");
         kfree(pathbuf);
 }
@@ -145,12 +139,13 @@ void ima_file_free(struct file *file)
         ima_check_last_writer(iint, inode, file);
 }
 
-static int process_measurement(struct file *file, const unsigned char *filename,
+static int process_measurement(struct file *file, const char *filename,
                                int mask, int function)
 {
         struct inode *inode = file->f_dentry->d_inode;
         struct integrity_iint_cache *iint;
-        unsigned char *pathname = NULL, *pathbuf = NULL;
+        char *pathbuf = NULL;
+        const char *pathname = NULL;
         int rc = -ENOMEM, action, must_appraise;
 
         if (!ima_initialized || !S_ISREG(inode->i_mode))
@@ -187,24 +182,18 @@ static int process_measurement(struct file *file, const unsigned char *filename,
         if (rc != 0)
                 goto out;
 
-        if (function != BPRM_CHECK) {
-                /* We will allow 11 spaces for ' (deleted)' to be appended */
-                pathbuf = kmalloc(PATH_MAX + 11, GFP_KERNEL);
-                if (pathbuf) {
-                        pathname =
-                            d_path(&file->f_path, pathbuf, PATH_MAX + 11);
-                        if (IS_ERR(pathname))
-                                pathname = NULL;
-                }
-        }
+        if (function != BPRM_CHECK)
+                pathname = ima_d_path(&file->f_path, &pathbuf);
+
+        if (!pathname)
+                pathname = filename;
+
         if (action & IMA_MEASURE)
-                ima_store_measurement(iint, file,
-                                      !pathname ? filename : pathname);
+                ima_store_measurement(iint, file, pathname);
         if (action & IMA_APPRAISE)
-                rc = ima_appraise_measurement(iint, file,
-                                              !pathname ? filename : pathname);
+                rc = ima_appraise_measurement(iint, file, pathname);
         if (action & IMA_AUDIT)
-                ima_audit_measurement(iint, !pathname ? filename : pathname);
+                ima_audit_measurement(iint, pathname);
         kfree(pathbuf);
 out:
         mutex_unlock(&inode->i_mutex);