This cosmetic change that is needed for audit support, specifically to
be able to filter according to cross-execution boundaries.
Replace hardcoded LANDLOCK_SCOPE_SIGNAL with the signal_scope.scope
variable.
Use scoped guards for RCU read-side critical sections.
Cc: Günther Noack <gno...@google.com>
Signed-off-by: Mickaël Salaün <m...@digikod.net>
---
Changes since v6:
- Rebase on the signal scoping fix.
Changes since v4:
- New patch.
---
security/landlock/task.c | 49 +++++++++++++++++++++-------------------
1 file changed, 26 insertions(+), 23 deletions(-)
diff --git a/security/landlock/task.c b/security/landlock/task.c
index e04646d80e78..a44b8e4a6ea6 100644
--- a/security/landlock/task.c
+++ b/security/landlock/task.c
@@ -7,6 +7,7 @@
*/
#include <asm/current.h>
+#include <linux/cleanup.h>
#include <linux/cred.h>
#include <linux/errno.h>
#include <linux/kernel.h>
@@ -214,15 +215,15 @@ static int hook_unix_stream_connect(struct sock *const
sock,
struct sock *const other,
struct sock *const newsk)
{
- const struct landlock_ruleset *const dom =
- landlock_get_applicable_domain(landlock_get_current_domain(),
- unix_scope);
+ const struct landlock_cred_security *const subject =
+ landlock_get_applicable_subject(current_cred(), unix_scope,
+ NULL);
/* Quick return for non-landlocked tasks. */
- if (!dom)
+ if (!subject)
return 0;
- if (is_abstract_socket(other) && sock_is_scoped(other, dom))
+ if (is_abstract_socket(other) && sock_is_scoped(other, subject->domain))
return -EPERM;
return 0;
@@ -231,11 +232,11 @@ static int hook_unix_stream_connect(struct sock *const
sock,
static int hook_unix_may_send(struct socket *const sock,
struct socket *const other)
{
- const struct landlock_ruleset *const dom =
- landlock_get_applicable_domain(landlock_get_current_domain(),
- unix_scope);
+ const struct landlock_cred_security *const subject =
+ landlock_get_applicable_subject(current_cred(), unix_scope,
+ NULL);
- if (!dom)
+ if (!subject)
return 0;
/*
@@ -245,7 +246,8 @@ static int hook_unix_may_send(struct socket *const sock,
if (unix_peer(sock->sk) == other->sk)
return 0;
- if (is_abstract_socket(other->sk) && sock_is_scoped(other->sk, dom))
+ if (is_abstract_socket(other->sk) &&
+ sock_is_scoped(other->sk, subject->domain))
return -EPERM;
return 0;
@@ -257,15 +259,12 @@ static const struct access_masks signal_scope = {
static int hook_task_kill(struct task_struct *const p,
struct kernel_siginfo *const info, const int sig,
- const struct cred *const cred)
+ const struct cred *cred)
{
bool is_scoped;
- const struct landlock_ruleset *dom;
+ const struct landlock_cred_security *subject;
- if (cred) {
- /* Dealing with USB IO. */
- dom = landlock_cred(cred)->domain;
- } else {
+ if (!cred) {
/*
* Always allow sending signals between threads of the same
process.
* This is required for process credential changes by the
Native POSIX
@@ -277,18 +276,22 @@ static int hook_task_kill(struct task_struct *const p,
if (same_thread_group(p, current))
return 0;
- dom = landlock_get_current_domain();
+ /* Not dealing with USB IO. */
+ cred = current_cred();
}
- dom = landlock_get_applicable_domain(dom, signal_scope);
+
+ subject = landlock_get_applicable_subject(cred, signal_scope, NULL);
/* Quick return for non-landlocked tasks. */
- if (!dom)
+ if (!subject)
return 0;
- rcu_read_lock();
- is_scoped = domain_is_scoped(dom, landlock_get_task_domain(p),
- LANDLOCK_SCOPE_SIGNAL);
- rcu_read_unlock();
+ scoped_guard(rcu)
+ {
+ is_scoped = domain_is_scoped(subject->domain,
+ landlock_get_task_domain(p),
+ signal_scope.scope);
+ }
if (is_scoped)
return -EPERM;
--
2.49.0
