Integrity: IMA file free imbalance
The number of calls to ima_path_check()/ima_file_free()
should be balanced. An extra call to fput(), indicates
the file could have been accessed without first being
measured.
Although f_count is incremented/decremented in places other
than fget/fput, like fget_light/fput_light and get_file, the
current task must already hold a file refcnt. The call to
__fput() is delayed until the refcnt becomes 0, resulting
in ima_file_free() flagging any changes.
- add hook to increment opencount for IPC shared memory(SYSV),
shmat files, and /dev/zero
- moved NULL iint test in opencount_get()
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/ipc/shm.c b/ipc/shm.c
index 38a0557..d39bd76 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -39,6 +39,7 @@
#include <linux/nsproxy.h>
#include <linux/mount.h>
#include <linux/ipc_namespace.h>
+#include <linux/ima.h>
#include <asm/uaccess.h>
@@ -381,6 +382,7 @@
error = PTR_ERR(file);
if (IS_ERR(file))
goto no_file;
+ ima_shm_check(file);
id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
if (id < 0) {
@@ -888,6 +890,7 @@
file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations);
if (!file)
goto out_free;
+ ima_shm_check(file);
file->private_data = sfd;
file->f_mapping = shp->shm_file->f_mapping;