selinux lsm IB/core: Implement LSM notification system

Add a generic notificaiton mechanism in the LSM. Interested consumers
can register a callback with the LSM and security modules can produce
events.

Because access to Infiniband QPs are enforced in the setup phase of a
connection security should be enforced again if the policy changes.
Register infiniband devices for policy change notification and check all
QPs on that device when the notification is received.

Add a call to the notification mechanism from SELinux when the AVC
cache changes or setenforce is cleared.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Daniel Jurgens 2017-05-19 15:48:53 +03:00 committed by Paul Moore
parent d291f1a652
commit 8f408ab64b
5 changed files with 109 additions and 0 deletions

View File

@ -39,6 +39,8 @@
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/security.h>
#include <linux/notifier.h>
#include <rdma/rdma_netlink.h>
#include <rdma/ib_addr.h>
#include <rdma/ib_cache.h>
@ -82,6 +84,14 @@ static LIST_HEAD(client_list);
static DEFINE_MUTEX(device_mutex);
static DECLARE_RWSEM(lists_rwsem);
static int ib_security_change(struct notifier_block *nb, unsigned long event,
void *lsm_data);
static void ib_policy_change_task(struct work_struct *work);
static DECLARE_WORK(ib_policy_change_work, ib_policy_change_task);
static struct notifier_block ibdev_lsm_nb = {
.notifier_call = ib_security_change,
};
static int ib_device_check_mandatory(struct ib_device *device)
{
@ -349,6 +359,40 @@ static int setup_port_pkey_list(struct ib_device *device)
return 0;
}
static void ib_policy_change_task(struct work_struct *work)
{
struct ib_device *dev;
down_read(&lists_rwsem);
list_for_each_entry(dev, &device_list, core_list) {
int i;
for (i = rdma_start_port(dev); i <= rdma_end_port(dev); i++) {
u64 sp;
int ret = ib_get_cached_subnet_prefix(dev,
i,
&sp);
WARN_ONCE(ret,
"ib_get_cached_subnet_prefix err: %d, this should never happen here\n",
ret);
ib_security_cache_change(dev, i, sp);
}
}
up_read(&lists_rwsem);
}
static int ib_security_change(struct notifier_block *nb, unsigned long event,
void *lsm_data)
{
if (event != LSM_POLICY_CHANGE)
return NOTIFY_DONE;
schedule_work(&ib_policy_change_work);
return NOTIFY_OK;
}
/**
* ib_register_device - Register an IB device with IB core
* @device:Device to register
@ -1115,10 +1159,18 @@ static int __init ib_core_init(void)
goto err_sa;
}
ret = register_lsm_notifier(&ibdev_lsm_nb);
if (ret) {
pr_warn("Couldn't register LSM notifier. ret %d\n", ret);
goto err_ibnl_clients;
}
ib_cache_setup();
return 0;
err_ibnl_clients:
ib_remove_ibnl_clients();
err_sa:
ib_sa_cleanup();
err_mad:
@ -1138,6 +1190,7 @@ err:
static void __exit ib_core_cleanup(void)
{
unregister_lsm_notifier(&ibdev_lsm_nb);
ib_cache_cleanup();
ib_remove_ibnl_clients();
ib_sa_cleanup();

View File

@ -69,6 +69,10 @@ struct audit_krule;
struct user_namespace;
struct timezone;
enum lsm_event {
LSM_POLICY_CHANGE,
};
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, int audit);
@ -164,6 +168,10 @@ struct security_mnt_opts {
int num_mnt_opts;
};
int call_lsm_notifier(enum lsm_event event, void *data);
int register_lsm_notifier(struct notifier_block *nb);
int unregister_lsm_notifier(struct notifier_block *nb);
static inline void security_init_mnt_opts(struct security_mnt_opts *opts)
{
opts->mnt_opts = NULL;
@ -382,6 +390,21 @@ int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
struct security_mnt_opts {
};
static inline int call_lsm_notifier(enum lsm_event event, void *data)
{
return 0;
}
static inline int register_lsm_notifier(struct notifier_block *nb)
{
return 0;
}
static inline int unregister_lsm_notifier(struct notifier_block *nb)
{
return 0;
}
static inline void security_init_mnt_opts(struct security_mnt_opts *opts)
{
}

View File

@ -35,6 +35,8 @@
#define SECURITY_NAME_MAX 10
struct security_hook_heads security_hook_heads __lsm_ro_after_init;
static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain);
char *lsm_names;
/* Boot-time LSM user choice */
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] =
@ -166,6 +168,24 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
panic("%s - Cannot get early memory.\n", __func__);
}
int call_lsm_notifier(enum lsm_event event, void *data)
{
return atomic_notifier_call_chain(&lsm_notifier_chain, event, data);
}
EXPORT_SYMBOL(call_lsm_notifier);
int register_lsm_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&lsm_notifier_chain, nb);
}
EXPORT_SYMBOL(register_lsm_notifier);
int unregister_lsm_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&lsm_notifier_chain, nb);
}
EXPORT_SYMBOL(unregister_lsm_notifier);
/*
* Hook list operation macros.
*

View File

@ -171,6 +171,14 @@ static int selinux_netcache_avc_callback(u32 event)
return 0;
}
static int selinux_lsm_notifier_avc_callback(u32 event)
{
if (event == AVC_CALLBACK_RESET)
call_lsm_notifier(LSM_POLICY_CHANGE, NULL);
return 0;
}
/*
* initialise the security for the init task
*/
@ -6387,6 +6395,9 @@ static __init int selinux_init(void)
if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
panic("SELinux: Unable to register AVC netcache callback\n");
if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
panic("SELinux: Unable to register AVC LSM notifier callback\n");
if (selinux_enforcing)
printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n");
else

View File

@ -154,6 +154,8 @@ static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
avc_ss_reset(0);
selnl_notify_setenforce(selinux_enforcing);
selinux_status_update_setenforce(selinux_enforcing);
if (!selinux_enforcing)
call_lsm_notifier(LSM_POLICY_CHANGE, NULL);
}
length = count;
out: