From 8f408ab64be6319cb7736cbc6982838dcc362306 Mon Sep 17 00:00:00 2001 From: Daniel Jurgens Date: Fri, 19 May 2017 15:48:53 +0300 Subject: [PATCH] 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 Acked-by: James Morris Acked-by: Doug Ledford Signed-off-by: Paul Moore --- drivers/infiniband/core/device.c | 53 ++++++++++++++++++++++++++++++++ include/linux/security.h | 23 ++++++++++++++ security/security.c | 20 ++++++++++++ security/selinux/hooks.c | 11 +++++++ security/selinux/selinuxfs.c | 2 ++ 5 files changed, 109 insertions(+) diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index 96e730cc9b81..631eaa9daf65 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -39,6 +39,8 @@ #include #include #include +#include +#include #include #include #include @@ -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(); diff --git a/include/linux/security.h b/include/linux/security.h index 8c73ee073bab..f96e333f6042 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -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) { } diff --git a/security/security.c b/security/security.c index 2a9d1a7fa1f8..b59be0d6535f 100644 --- a/security/security.c +++ b/security/security.c @@ -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. * diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index cfb7ce339adc..b005acbcc6e9 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -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 diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 82adb78a58f7..9010a3632d6f 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -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: -- 2.20.1