ima: fix ima_d_path() possible race with rename
am: d9cc31683a
Change-Id: I1b44484dab9a62445e9da169e4b30e5f4a122ea6
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index db25f54..df7834a 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -173,7 +173,7 @@
struct inode *inode,
const unsigned char *filename, int pcr);
void ima_free_template_entry(struct ima_template_entry *entry);
-const char *ima_d_path(const struct path *path, char **pathbuf);
+const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
/* IMA policy related functions */
int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 9df26a2..d01a52f 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -318,7 +318,17 @@
iint->flags |= IMA_AUDITED;
}
-const char *ima_d_path(const struct path *path, char **pathbuf)
+/*
+ * ima_d_path - return a pointer to the full pathname
+ *
+ * Attempt to return a pointer to the full pathname for use in the
+ * IMA measurement list, IMA audit records, and auditing logs.
+ *
+ * On failure, return a pointer to a copy of the filename, not dname.
+ * Returning a pointer to dname, could result in using the pointer
+ * after the memory has been freed.
+ */
+const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf)
{
char *pathname = NULL;
@@ -331,5 +341,11 @@
pathname = NULL;
}
}
- return pathname ?: (const char *)path->dentry->d_name.name;
+
+ if (!pathname) {
+ strlcpy(namebuf, path->dentry->d_name.name, NAME_MAX);
+ pathname = namebuf;
+ }
+
+ return pathname;
}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 423d111..0e87629 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -83,6 +83,7 @@
const char **pathname)
{
struct inode *inode = file_inode(file);
+ char filename[NAME_MAX];
fmode_t mode = file->f_mode;
bool send_tomtou = false, send_writers = false;
@@ -102,7 +103,7 @@
if (!send_tomtou && !send_writers)
return;
- *pathname = ima_d_path(&file->f_path, pathbuf);
+ *pathname = ima_d_path(&file->f_path, pathbuf, filename);
if (send_tomtou)
ima_add_violation(file, *pathname, iint,
@@ -161,6 +162,7 @@
struct integrity_iint_cache *iint = NULL;
struct ima_template_desc *template_desc;
char *pathbuf = NULL;
+ char filename[NAME_MAX];
const char *pathname = NULL;
int rc = -ENOMEM, action, must_appraise;
int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
@@ -239,8 +241,8 @@
goto out_digsig;
}
- if (!pathname) /* ima_rdwr_violation possibly pre-fetched */
- pathname = ima_d_path(&file->f_path, &pathbuf);
+ if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */
+ pathname = ima_d_path(&file->f_path, &pathbuf, filename);
if (action & IMA_MEASURE)
ima_store_measurement(iint, file, pathname,