From: David Howells <dhowells@redhat.com> To: keyrings@vger.kernel.org, linux-usb@vger.kernel.org, linux-block@vger.kernel.org Cc: dhowells@redhat.com, torvalds@linux-foundation.org, Casey Schaufler <casey@schaufler-ca.com>, Stephen Smalley <sds@tycho.nsa.gov>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, nicolas.dichtel@6wind.com, raven@themaw.net, Christian Brauner <christian@brauner.io>, dhowells@redhat.com, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 03/11] security: Add a hook for the point of notification insertion [ver #8] Date: Wed, 04 Sep 2019 23:16:12 +0100 Message-ID: <156763537237.18676.12991040129330701275.stgit@warthog.procyon.org.uk> (raw) In-Reply-To: <156763534546.18676.3530557439501101639.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 | 15 ++++++++++++++- security/security.c | 9 +++++++++ 3 files changed, 37 insertions(+), 1 deletion(-) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index b0cdefcda4e6..257d803dcf6f 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1424,6 +1424,12 @@ * 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. @@ -1706,6 +1712,11 @@ 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, @@ -1988,6 +1999,9 @@ 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 3be44354d308..24c54b9ff0a1 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 @@ -1222,6 +1224,18 @@ 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 @@ -1847,4 +1861,3 @@ static inline void security_bpf_prog_free(struct bpf_prog_aux *aux) #endif /* CONFIG_BPF_SYSCALL */ #endif /* ! __LINUX_SECURITY_H */ - diff --git a/security/security.c b/security/security.c index 007eb48bc848..b719c5a5b2ba 100644 --- a/security/security.c +++ b/security/security.c @@ -1916,6 +1916,15 @@ 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 index Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-09-04 22:15 [PATCH 00/11] Keyrings, Block and USB notifications " David Howells 2019-09-04 22:15 ` [PATCH 01/11] uapi: General notification ring definitions " David Howells 2019-09-04 22:16 ` [PATCH 02/11] security: Add hooks to rule on setting a watch " David Howells 2019-09-04 22:16 ` David Howells [this message] 2019-09-04 22:16 ` [PATCH 04/11] General notification queue with user mmap()'able ring buffer " David Howells 2019-09-04 22:16 ` [PATCH 05/11] keys: Add a notification facility " David Howells 2019-09-04 22:16 ` [PATCH 06/11] Add a general, global device notification watch list " David Howells 2019-09-04 22:16 ` [PATCH 07/11] block: Add block layer notifications " David Howells 2019-09-04 22:16 ` [PATCH 08/11] usb: Add USB subsystem " David Howells 2019-09-04 22:17 ` [PATCH 09/11] Add sample notification program " David Howells 2019-09-04 22:17 ` [PATCH 10/11] selinux: Implement the watch_key security hook " David Howells 2019-09-04 22:17 ` [PATCH 11/11] smack: Implement the watch_key and post_notification hooks " David Howells 2019-09-04 22:28 ` [PATCH 00/11] Keyrings, Block and USB notifications " Linus Torvalds 2019-09-05 17:01 ` Why add the general notification queue and its sources David Howells 2019-09-05 17:19 ` Linus Torvalds 2019-09-05 18:32 ` Ray Strode 2019-09-05 20:39 ` Linus Torvalds 2019-09-06 19:32 ` Ray Strode 2019-09-06 19:41 ` Ray Strode 2019-09-06 19:53 ` Robbie Harwood 2019-09-05 21:32 ` David Howells 2019-09-05 22:08 ` Linus Torvalds 2019-09-05 23:18 ` David Howells 2019-09-06 0:07 ` Linus Torvalds 2019-09-06 10:09 ` David Howells 2019-09-06 15:35 ` Linus Torvalds 2019-09-06 15:53 ` Linus Torvalds 2019-09-06 16:12 ` Steven Whitehouse 2019-09-06 17:07 ` Linus Torvalds 2019-09-06 17:14 ` Linus Torvalds 2019-09-06 21:19 ` David Howells 2019-09-06 17:14 ` Andy Lutomirski 2019-09-05 18:37 ` Steven Whitehouse 2019-09-05 18:51 ` Ray Strode 2019-09-05 20:09 ` David Lehman 2019-09-05 18:33 ` Greg Kroah-Hartman
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