From: David Howells <dhowells@redhat.com>
To: torvalds@linux-foundation.org, viro@zeniv.linux.org.uk
Cc: Casey Schaufler <casey@schaufler-ca.com>,
Stephen Smalley <sds@tycho.nsa.gov>,
linux-security-module@vger.kernel.org,
dhowells@redhat.comdhowells@redhat.comcasey@schaufler-ca.comsds@tycho.nsa.gov,
nicolas.dichtel@6wind.com, raven@themaw.net,
christian@brauner.io, andres@anarazel.de, jlayton@redhat.com,
dray@redhat.com, kzak@redhat.com, keyrings@vger.kernel.org,
linux-api@vger.kernel.org,
linux-fsdevel@vger.kernel.orglinux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [RFC PATCH 03/17] security: Add a hook for the point of notification insertion [ver #4]
Date: Mon, 09 Mar 2020 12:17:41 +0000 [thread overview]
Message-ID: <158375626100.334846.3654197678658672620.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <158375623086.334846.16121725232323108842.stgit@warthog.procyon.org.uk>
Add a security hook that allows an LSM to rule on whether a notification
message is allowed to be inserted into a particular watch queue.
The hook is given the following information:
(1) The credentials of the triggerer (which may be init_cred for a system
notification, eg. a hardware error).
(2) The credentials of the whoever set the watch.
(3) The notification message.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Casey Schaufler <casey@schaufler-ca.com>
cc: Stephen Smalley <sds@tycho.nsa.gov>
cc: linux-security-module@vger.kernel.org
---
include/linux/lsm_hooks.h | 14 ++++++++++++++
include/linux/security.h | 14 ++++++++++++++
security/security.c | 9 +++++++++
3 files changed, 37 insertions(+)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 79d7c73676d7..16530255dc11 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1427,6 +1427,12 @@
* Check to see if a process is allowed to watch for event notifications
* from devices (as a global set).
*
+ * @post_notification:
+ * Check to see if a watch notification can be posted to a particular
+ * queue.
+ * @w_cred: The credentials of the whoever set the watch.
+ * @cred: The event-triggerer's credentials
+ * @n: The notification being posted
*
* Security hooks for using the eBPF maps and programs functionalities through
* eBPF syscalls.
@@ -1716,6 +1722,11 @@ union security_list_options {
#ifdef CONFIG_DEVICE_NOTIFICATIONS
int (*watch_devices)(void);
#endif
+#ifdef CONFIG_WATCH_QUEUE
+ int (*post_notification)(const struct cred *w_cred,
+ const struct cred *cred,
+ struct watch_notification *n);
+#endif
#ifdef CONFIG_SECURITY_NETWORK
int (*unix_stream_connect)(struct sock *sock, struct sock *other,
@@ -2009,6 +2020,9 @@ struct security_hook_heads {
#ifdef CONFIG_DEVICE_NOTIFICATIONS
struct hlist_head watch_devices;
#endif
+#ifdef CONFIG_WATCH_QUEUE
+ struct hlist_head post_notification;
+#endif /* CONFIG_WATCH_QUEUE */
#ifdef CONFIG_SECURITY_NETWORK
struct hlist_head unix_stream_connect;
struct hlist_head unix_may_send;
diff --git a/include/linux/security.h b/include/linux/security.h
index 7a36064a64ea..910a1efa9a79 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -57,6 +57,8 @@ struct mm_struct;
struct fs_context;
struct fs_parameter;
enum fs_value_type;
+struct watch;
+struct watch_notification;
/* Default (no) options for the capable function */
#define CAP_OPT_NONE 0x0
@@ -1292,6 +1294,18 @@ static inline int security_watch_devices(void)
return 0;
}
#endif
+#if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE)
+int security_post_notification(const struct cred *w_cred,
+ const struct cred *cred,
+ struct watch_notification *n);
+#else
+static inline int security_post_notification(const struct cred *w_cred,
+ const struct cred *cred,
+ struct watch_notification *n)
+{
+ return 0;
+}
+#endif
#ifdef CONFIG_SECURITY_NETWORK
diff --git a/security/security.c b/security/security.c
index 22877f47cf62..db7b574c9c70 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1988,6 +1988,15 @@ int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
}
EXPORT_SYMBOL(security_inode_getsecctx);
+#ifdef CONFIG_WATCH_QUEUE
+int security_post_notification(const struct cred *w_cred,
+ const struct cred *cred,
+ struct watch_notification *n)
+{
+ return call_int_hook(post_notification, 0, w_cred, cred, n);
+}
+#endif /* CONFIG_WATCH_QUEUE */
+
#ifdef CONFIG_KEY_NOTIFICATIONS
int security_watch_key(struct key *key)
{
next prev parent reply other threads:[~2020-03-09 12:17 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-09 12:17 [RFC PATCH 00/17] pipe: Keyrings, mount and superblock notifications [ver #4] David Howells
2020-03-09 12:17 ` [RFC PATCH 01/17] uapi: General notification queue definitions " David Howells
2020-03-09 12:17 ` [RFC PATCH 02/17] security: Add hooks to rule on setting a watch " David Howells
2020-03-09 12:17 ` David Howells [this message]
2020-03-09 12:17 ` [RFC PATCH 04/17] pipe: Add O_NOTIFICATION_PIPE " David Howells
2020-03-09 12:17 ` [RFC PATCH 05/17] pipe: Add general notification queue support " David Howells
2020-03-09 12:18 ` [RFC PATCH 06/17] watch_queue: Add a key/keyring notification facility " David Howells
2020-03-09 12:18 ` [RFC PATCH 07/17] Add sample notification program " David Howells
2020-03-09 12:18 ` [RFC PATCH 08/17] pipe: Allow buffers to be marked read-whole-or-error for notifications " David Howells
2020-03-09 12:18 ` [RFC PATCH 09/17] pipe: Add notification lossage handling " David Howells
2020-03-09 12:18 ` [RFC PATCH 10/17] selinux: Implement the watch_key security hook " David Howells
2020-03-09 12:18 ` [RFC PATCH 11/17] smack: Implement the watch_key and post_notification hooks " David Howells
2020-03-09 12:19 ` [RFC PATCH 12/17] watch_queue: Add security hooks to rule on setting mount and sb watches " David Howells
2020-03-09 12:19 ` [RFC PATCH 13/17] watch_queue: Implement mount topology and attribute change notifications " David Howells
2020-03-09 12:19 ` [RFC PATCH 14/17] watch_queue: sample: Display mount tree " David Howells
2020-03-09 12:19 ` [RFC PATCH 15/17] watch_queue: Introduce a non-repeating system-unique superblock ID " David Howells
2020-03-09 12:19 ` [RFC PATCH 16/17] watch_queue: Add superblock notifications " David Howells
2020-03-09 12:19 ` [RFC PATCH 17/17] watch_queue: sample: Display " David Howells
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