ima: prevent unnecessary policy checking
ima_rdwr_violation_check is called for every file openning.
The function checks the policy even when violation condition
is not met. It causes unnecessary policy checking.
This patch does policy checking only if violation condition is met.
Changelog:
- check writecount is greater than zero (Mimi)
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index dcc98cf..7689c1e 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -81,7 +81,6 @@
{
struct inode *inode = file_inode(file);
fmode_t mode = file->f_mode;
- int must_measure;
bool send_tomtou = false, send_writers = false;
char *pathbuf = NULL;
const char *pathname;
@@ -94,16 +93,12 @@
if (mode & FMODE_WRITE) {
if (atomic_read(&inode->i_readcount) && IS_IMA(inode))
send_tomtou = true;
- goto out;
+ } else {
+ if ((atomic_read(&inode->i_writecount) > 0) &&
+ ima_must_measure(inode, MAY_READ, FILE_CHECK))
+ send_writers = true;
}
- must_measure = ima_must_measure(inode, MAY_READ, FILE_CHECK);
- if (!must_measure)
- goto out;
-
- if (atomic_read(&inode->i_writecount) > 0)
- send_writers = true;
-out:
mutex_unlock(&inode->i_mutex);
if (!send_tomtou && !send_writers)