ima: forbid write access to files with digital signatures
This patch forbids write access to files with digital signatures, as they
are considered immutable.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.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 d743c9a..cd00ba3 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -175,12 +175,12 @@
if (!action) {
if (iint->flags & IMA_APPRAISED)
rc = iint->ima_status;
- goto out;
+ goto out_digsig;
}
rc = ima_collect_measurement(iint, file);
if (rc != 0)
- goto out;
+ goto out_digsig;
if (function != BPRM_CHECK)
pathname = ima_d_path(&file->f_path, &pathbuf);
@@ -195,6 +195,9 @@
if (action & IMA_AUDIT)
ima_audit_measurement(iint, pathname);
kfree(pathbuf);
+out_digsig:
+ if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
+ rc = -EACCES;
out:
mutex_unlock(&inode->i_mutex);
if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE))
