1 files changed, 80 insertions, 76 deletions

diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c
index c51d2266587e..df5712cea685 100644
--- a/security/apparmor/ipc.c
+++ b/security/apparmor/ipc.c
@@ -1,112 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * AppArmor security module
  *
  * This file contains AppArmor ipc mediation
  *
  * Copyright (C) 1998-2008 Novell/SUSE
- * Copyright 2009-2010 Canonical Ltd.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation, version 2 of the
- * License.
+ * Copyright 2009-2017 Canonical Ltd.
  */
 
 #include <linux/gfp.h>
-#include <linux/ptrace.h>
 
 #include "include/audit.h"
 #include "include/capability.h"
-#include "include/context.h"
+#include "include/cred.h"
 #include "include/policy.h"
 #include "include/ipc.h"
+#include "include/sig_names.h"
+
 
-/* call back to audit ptrace fields */
-static void audit_cb(struct audit_buffer *ab, void *va)
+static inline int map_signal_num(int sig)
 {
-	struct common_audit_data *sa = va;
-	audit_log_format(ab, " target=");
-	audit_log_untrustedstring(ab, sa->aad->target);
+	if (sig > SIGRTMAX)
+		return SIGUNKNOWN;
+	else if (sig >= SIGRTMIN)
+		return sig - SIGRTMIN + SIGRT_BASE;
+	else if (sig < MAXMAPPED_SIG)
+		return sig_map[sig];
+	return SIGUNKNOWN;
 }
 
 /**
- * aa_audit_ptrace - do auditing for ptrace
- * @profile: profile being enforced  (NOT NULL)
- * @target: profile being traced (NOT NULL)
- * @error: error condition
+ * audit_signal_mask - convert mask to permission string
+ * @mask: permission mask to convert
  *
- * Returns: %0 or error code
+ * Returns: pointer to static string
  */
-static int aa_audit_ptrace(struct aa_profile *profile,
-			   struct aa_profile *target, int error)
+static const char *audit_signal_mask(u32 mask)
 {
-	struct common_audit_data sa;
-	struct apparmor_audit_data aad = {0,};
-	sa.type = LSM_AUDIT_DATA_NONE;
-	sa.aad = &aad;
-	aad.op = OP_PTRACE;
-	aad.target = target;
-	aad.error = error;
-
-	return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_ATOMIC, &sa,
-			audit_cb);
+	if (mask & MAY_READ)
+		return "receive";
+	if (mask & MAY_WRITE)
+		return "send";
+	return "";
 }
 
 /**
- * aa_may_ptrace - test if tracer task can trace the tracee
- * @tracer_task: task who will do the tracing  (NOT NULL)
- * @tracer: profile of the task doing the tracing  (NOT NULL)
- * @tracee: task to be traced
- * @mode: whether PTRACE_MODE_READ || PTRACE_MODE_ATTACH
- *
- * Returns: %0 else error code if permission denied or error
+ * audit_signal_cb() - call back for signal specific audit fields
+ * @ab: audit_buffer  (NOT NULL)
+ * @va: audit struct to audit values of  (NOT NULL)
  */
-int aa_may_ptrace(struct task_struct *tracer_task, struct aa_profile *tracer,
-		  struct aa_profile *tracee, unsigned int mode)
+static void audit_signal_cb(struct audit_buffer *ab, void *va)
 {
-	/* TODO: currently only based on capability, not extended ptrace
-	 *       rules,
-	 *       Test mode for PTRACE_MODE_READ || PTRACE_MODE_ATTACH
-	 */
+	struct common_audit_data *sa = va;
+	struct apparmor_audit_data *ad = aad(sa);
 
-	if (unconfined(tracer) || tracer == tracee)
-		return 0;
-	/* log this capability request */
-	return aa_capable(tracer_task, tracer, CAP_SYS_PTRACE, 1);
+	if (ad->request & AA_SIGNAL_PERM_MASK) {
+		audit_log_format(ab, " requested_mask=\"%s\"",
+				 audit_signal_mask(ad->request));
+		if (ad->denied & AA_SIGNAL_PERM_MASK) {
+			audit_log_format(ab, " denied_mask=\"%s\"",
+					 audit_signal_mask(ad->denied));
+		}
+	}
+	if (ad->signal == SIGUNKNOWN)
+		audit_log_format(ab, "signal=unknown(%d)",
+				 ad->unmappedsig);
+	else if (ad->signal < MAXMAPPED_SIGNAME)
+		audit_log_format(ab, " signal=%s", sig_names[ad->signal]);
+	else
+		audit_log_format(ab, " signal=rtmin+%d",
+				 ad->signal - SIGRT_BASE);
+	audit_log_format(ab, " peer=");
+	aa_label_xaudit(ab, labels_ns(ad->subj_label), ad->peer,
+			FLAGS_NONE, GFP_ATOMIC);
 }
 
-/**
- * aa_ptrace - do ptrace permission check and auditing
- * @tracer: task doing the tracing (NOT NULL)
- * @tracee: task being traced (NOT NULL)
- * @mode: ptrace mode either PTRACE_MODE_READ || PTRACE_MODE_ATTACH
- *
- * Returns: %0 else error code if permission denied or error
- */
-int aa_ptrace(struct task_struct *tracer, struct task_struct *tracee,
-	      unsigned int mode)
+static int profile_signal_perm(const struct cred *cred,
+			       struct aa_profile *profile,
+			       struct aa_label *peer, u32 request,
+			       struct apparmor_audit_data *ad)
 {
-	/*
-	 * tracer can ptrace tracee when
-	 * - tracer is unconfined ||
-	 *   - tracer is in complain mode
-	 *   - tracer has rules allowing it to trace tracee currently this is:
-	 *       - confined by the same profile ||
-	 *       - tracer profile has CAP_SYS_PTRACE
-	 */
+	struct aa_ruleset *rules = profile->label.rules[0];
+	struct aa_perms perms;
+	aa_state_t state;
 
-	struct aa_profile *tracer_p = aa_get_task_profile(tracer);
-	int error = 0;
-
-	if (!unconfined(tracer_p)) {
-		struct aa_profile *tracee_p = aa_get_task_profile(tracee);
+	if (profile_unconfined(profile))
+		return 0;
 
-		error = aa_may_ptrace(tracer, tracer_p, tracee_p, mode);
-		error = aa_audit_ptrace(tracer_p, tracee_p, error);
+	ad->subj_cred = cred;
+	ad->peer = peer;
+	/* TODO: secondary cache check <profile, profile, perm> */
+	state = RULE_MEDIATES(rules, AA_CLASS_SIGNAL);
+	if (!state)
+		return 0;
+	state = aa_dfa_next(rules->policy->dfa, state, ad->signal);
+	aa_label_match(profile, rules, peer, state, false, request, &perms);
+	aa_apply_modes_to_perms(profile, &perms);
+	return aa_check_perms(profile, &perms, request, ad, audit_signal_cb);
+}
 
-		aa_put_profile(tracee_p);
-	}
-	aa_put_profile(tracer_p);
+int aa_may_signal(const struct cred *subj_cred, struct aa_label *sender,
+		  const struct cred *target_cred, struct aa_label *target,
+		  int sig)
+{
+	struct aa_profile *profile;
+	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_SIGNAL, OP_SIGNAL);
 
-	return error;
+	ad.signal = map_signal_num(sig);
+	ad.unmappedsig = sig;
+	return xcheck_labels(sender, target, profile,
+			     profile_signal_perm(subj_cred, profile, target,
+						 MAY_WRITE, &ad),
+			     profile_signal_perm(target_cred, profile, sender,
+						 MAY_READ, &ad));
 }