1 files changed, 222 insertions, 0 deletions
diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c
new file mode 100644
index 000000000..aacd1e95c
--- /dev/null
+++ b/security/apparmor/ipc.c
@@ -0,0 +1,222 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor ipc mediation
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2017 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.
+ */
+
+#include <linux/gfp.h>
+#include <linux/ptrace.h>
+
+#include "include/audit.h"
+#include "include/capability.h"
+#include "include/cred.h"
+#include "include/policy.h"
+#include "include/ipc.h"
+#include "include/sig_names.h"
+
+/**
+ * audit_ptrace_mask - convert mask to permission string
+ * @buffer: buffer to write string to (NOT NULL)
+ * @mask: permission mask to convert
+ */
+static void audit_ptrace_mask(struct audit_buffer *ab, u32 mask)
+{
+	switch (mask) {
+	case MAY_READ:
+		audit_log_string(ab, "read");
+		break;
+	case MAY_WRITE:
+		audit_log_string(ab, "trace");
+		break;
+	case AA_MAY_BE_READ:
+		audit_log_string(ab, "readby");
+		break;
+	case AA_MAY_BE_TRACED:
+		audit_log_string(ab, "tracedby");
+		break;
+	}
+}
+
+/* call back to audit ptrace fields */
+static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
+{
+	struct common_audit_data *sa = va;
+
+	if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
+		audit_log_format(ab, " requested_mask=");
+		audit_ptrace_mask(ab, aad(sa)->request);
+
+		if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
+			audit_log_format(ab, " denied_mask=");
+			audit_ptrace_mask(ab, aad(sa)->denied);
+		}
+	}
+	audit_log_format(ab, " peer=");
+	aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
+			FLAGS_NONE, GFP_ATOMIC);
+}
+
+/* assumes check for PROFILE_MEDIATES is already done */
+/* TODO: conditionals */
+static int profile_ptrace_perm(struct aa_profile *profile,
+			     struct aa_label *peer, u32 request,
+			     struct common_audit_data *sa)
+{
+	struct aa_perms perms = { };
+
+	aad(sa)->peer = peer;
+	aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request,
+			       &perms);
+	aa_apply_modes_to_perms(profile, &perms);
+	return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb);
+}
+
+static int profile_tracee_perm(struct aa_profile *tracee,
+			       struct aa_label *tracer, u32 request,
+			       struct common_audit_data *sa)
+{
+	if (profile_unconfined(tracee) || unconfined(tracer) ||
+	    !PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE))
+		return 0;
+
+	return profile_ptrace_perm(tracee, tracer, request, sa);
+}
+
+static int profile_tracer_perm(struct aa_profile *tracer,
+			       struct aa_label *tracee, u32 request,
+			       struct common_audit_data *sa)
+{
+	if (profile_unconfined(tracer))
+		return 0;
+
+	if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE))
+		return profile_ptrace_perm(tracer, tracee, request, sa);
+
+	/* profile uses the old style capability check for ptrace */
+	if (&tracer->label == tracee)
+		return 0;
+
+	aad(sa)->label = &tracer->label;
+	aad(sa)->peer = tracee;
+	aad(sa)->request = 0;
+	aad(sa)->error = aa_capable(&tracer->label, CAP_SYS_PTRACE,
+				    CAP_OPT_NONE);
+
+	return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
+}
+
+/**
+ * aa_may_ptrace - test if tracer task can trace the tracee
+ * @tracer: label of the task doing the tracing  (NOT NULL)
+ * @tracee: task label to be traced
+ * @request: permission request
+ *
+ * Returns: %0 else error code if permission denied or error
+ */
+int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
+		  u32 request)
+{
+	struct aa_profile *profile;
+	u32 xrequest = request << PTRACE_PERM_SHIFT;
+	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
+
+	return xcheck_labels(tracer, tracee, profile,
+			profile_tracer_perm(profile, tracee, request, &sa),
+			profile_tracee_perm(profile, tracer, xrequest, &sa));
+}
+
+
+static inline int map_signal_num(int sig)
+{
+	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;
+}
+
+/**
+ * audit_file_mask - convert mask to permission string
+ * @buffer: buffer to write string to (NOT NULL)
+ * @mask: permission mask to convert
+ */
+static void audit_signal_mask(struct audit_buffer *ab, u32 mask)
+{
+	if (mask & MAY_READ)
+		audit_log_string(ab, "receive");
+	if (mask & MAY_WRITE)
+		audit_log_string(ab, "send");
+}
+
+/**
+ * audit_cb - call back for signal specific audit fields
+ * @ab: audit_buffer  (NOT NULL)
+ * @va: audit struct to audit values of  (NOT NULL)
+ */
+static void audit_signal_cb(struct audit_buffer *ab, void *va)
+{
+	struct common_audit_data *sa = va;
+
+	if (aad(sa)->request & AA_SIGNAL_PERM_MASK) {
+		audit_log_format(ab, " requested_mask=");
+		audit_signal_mask(ab, aad(sa)->request);
+		if (aad(sa)->denied & AA_SIGNAL_PERM_MASK) {
+			audit_log_format(ab, " denied_mask=");
+			audit_signal_mask(ab, aad(sa)->denied);
+		}
+	}
+	if (aad(sa)->signal == SIGUNKNOWN)
+		audit_log_format(ab, "signal=unknown(%d)",
+				 aad(sa)->unmappedsig);
+	else if (aad(sa)->signal < MAXMAPPED_SIGNAME)
+		audit_log_format(ab, " signal=%s", sig_names[aad(sa)->signal]);
+	else
+		audit_log_format(ab, " signal=rtmin+%d",
+				 aad(sa)->signal - SIGRT_BASE);
+	audit_log_format(ab, " peer=");
+	aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
+			FLAGS_NONE, GFP_ATOMIC);
+}
+
+static int profile_signal_perm(struct aa_profile *profile,
+			       struct aa_label *peer, u32 request,
+			       struct common_audit_data *sa)
+{
+	struct aa_perms perms;
+	unsigned int state;
+
+	if (profile_unconfined(profile) ||
+	    !PROFILE_MEDIATES(profile, AA_CLASS_SIGNAL))
+		return 0;
+
+	aad(sa)->peer = peer;
+	/* TODO: secondary cache check <profile, profile, perm> */
+	state = aa_dfa_next(profile->policy.dfa,
+			    profile->policy.start[AA_CLASS_SIGNAL],
+			    aad(sa)->signal);
+	aa_label_match(profile, peer, state, false, request, &perms);
+	aa_apply_modes_to_perms(profile, &perms);
+	return aa_check_perms(profile, &perms, request, sa, audit_signal_cb);
+}
+
+int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig)
+{
+	struct aa_profile *profile;
+	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SIGNAL);
+
+	aad(&sa)->signal = map_signal_num(sig);
+	aad(&sa)->unmappedsig = sig;
+	return xcheck_labels(sender, target, profile,
+			profile_signal_perm(profile, target, MAY_WRITE, &sa),
+			profile_signal_perm(profile, sender, MAY_READ, &sa));
+}