From 218d19e4b976907ea7f1855fdcbf83a38b758225 Mon Sep 17 00:00:00 2001
From: John Johansen <john.johansen@canonical.com>
Date: Fri, 9 Jun 2017 14:22:14 -0700
Subject: [PATCH 50/65] apparmor: move ptrace checks to using labels
Git-commit: b2d09ae449cedc6f276ac485c013d22a97d36992
Patch-mainline: v4.13-rc1
References: FATE#323500
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
security/apparmor/domain.c | 17 ++++---
security/apparmor/include/apparmor.h | 1 +
security/apparmor/include/ipc.h | 10 ++---
security/apparmor/ipc.c | 87 +++++++++---------------------------
security/apparmor/lsm.c | 23 +++++++++-
5 files changed, 58 insertions(+), 80 deletions(-)
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 8d6797c849fe..fab8923ae38e 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -51,14 +51,16 @@ void aa_free_domain_entries(struct aa_domain *domain)
/**
* may_change_ptraced_domain - check if can change profile on ptraced task
- * @to_profile: profile to change to (NOT NULL)
+ * @to_label: profile to change to (NOT NULL)
+ * @info: message if there is an error
*
* Check if current is ptraced and if so if the tracing task is allowed
* to trace the new domain
*
* Returns: %0 or error if change not allowed
*/
-static int may_change_ptraced_domain(struct aa_profile *to_profile)
+static int may_change_ptraced_domain(struct aa_label *to_label,
+ const char **info)
{
struct task_struct *tracer;
struct aa_label *tracerl = NULL;
@@ -74,13 +76,14 @@ static int may_change_ptraced_domain(struct aa_profile *to_profile)
if (!tracer || unconfined(tracerl))
goto out;
- error = aa_may_ptrace(labels_profile(tracerl), to_profile,
- PTRACE_MODE_ATTACH);
+ error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
out:
rcu_read_unlock();
aa_put_label(tracerl);
+ if (error)
+ *info = "ptrace prevents transition";
return error;
}
@@ -477,7 +480,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
}
if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
- error = may_change_ptraced_domain(new_profile);
+ error = may_change_ptraced_domain(&new_profile->label, &info);
if (error)
goto audit;
}
@@ -661,7 +664,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, int flags)
}
}
- error = may_change_ptraced_domain(hat);
+ error = may_change_ptraced_domain(&hat->label, &info);
if (error) {
info = "ptraced";
error = -EPERM;
@@ -782,7 +785,7 @@ int aa_change_profile(const char *fqname, int flags)
}
/* check if tracing task is allowed to trace target domain */
- error = may_change_ptraced_domain(target);
+ error = may_change_ptraced_domain(&target->label, &info);
if (error) {
info = "ptrace prevents transition";
goto audit;
diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
index c4a900488e76..aaf893f4e4f5 100644
--- a/security/apparmor/include/apparmor.h
+++ b/security/apparmor/include/apparmor.h
@@ -27,6 +27,7 @@
#define AA_CLASS_NET 4
#define AA_CLASS_RLIMITS 5
#define AA_CLASS_DOMAIN 6
+#define AA_CLASS_PTRACE 9
#define AA_CLASS_LABEL 16
#define AA_CLASS_LAST AA_CLASS_LABEL
diff --git a/security/apparmor/include/ipc.h b/security/apparmor/include/ipc.h
index 288ca76e2fb1..fb3e751e6eed 100644
--- a/security/apparmor/include/ipc.h
+++ b/security/apparmor/include/ipc.h
@@ -4,7 +4,7 @@
* This file contains AppArmor ipc mediation function definitions.
*
* Copyright (C) 1998-2008 Novell/SUSE
- * Copyright 2009-2010 Canonical Ltd.
+ * 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
@@ -19,10 +19,10 @@
struct aa_profile;
-int aa_may_ptrace(struct aa_profile *tracer, struct aa_profile *tracee,
- unsigned int mode);
+#define AA_PTRACE_TRACE MAY_WRITE
+#define AA_PTRACE_READ MAY_READ
-int aa_ptrace(struct task_struct *tracer, struct task_struct *tracee,
- unsigned int mode);
+int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
+ u32 request);
#endif /* __AA_IPC_H */
diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c
index 7678d94c4002..f81649369f05 100644
--- a/security/apparmor/ipc.c
+++ b/security/apparmor/ipc.c
@@ -4,7 +4,7 @@
* This file contains AppArmor ipc mediation
*
* Copyright (C) 1998-2008 Novell/SUSE
- * Copyright 2009-2010 Canonical Ltd.
+ * 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
@@ -25,88 +25,43 @@
static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
+
audit_log_format(ab, " peer=");
aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
FLAGS_NONE, GFP_ATOMIC);
}
-/**
- * aa_audit_ptrace - do auditing for ptrace
- * @profile: profile being enforced (NOT NULL)
- * @target: profile being traced (NOT NULL)
- * @error: error condition
- *
- * Returns: %0 or error code
- */
-static int aa_audit_ptrace(struct aa_profile *profile,
- struct aa_profile *target, int error)
+static int cross_ptrace_perm(struct aa_profile *tracer,
+ struct aa_profile *tracee, u32 request,
+ struct common_audit_data *sa)
{
- DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
+ /* policy uses the old style capability check for ptrace */
+ if (profile_unconfined(tracer) || tracer == tracee)
+ return 0;
- aad(&sa)->peer = &target->label;
- aad(&sa)->error = error;
+ aad(sa)->label = &tracer->label;
+ aad(sa)->peer = &tracee->label;
+ aad(sa)->request = 0;
+ aad(sa)->error = aa_capable(&tracer->label, CAP_SYS_PTRACE, 1);
- return aa_audit(AUDIT_APPARMOR_AUTO, profile, &sa, audit_ptrace_cb);
+ return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
}
/**
* aa_may_ptrace - test if tracer task can trace the tracee
- * @tracer: profile of the task doing the tracing (NOT NULL)
- * @tracee: task to be traced
- * @mode: whether PTRACE_MODE_READ || PTRACE_MODE_ATTACH
+ * @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_profile *tracer, struct aa_profile *tracee,
- unsigned int mode)
+int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
+ u32 request)
{
- /* TODO: currently only based on capability, not extended ptrace
- * rules,
- * Test mode for PTRACE_MODE_READ || PTRACE_MODE_ATTACH
- */
+ DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
- if (profile_unconfined(tracer) || tracer == tracee)
- return 0;
- /* log this capability request */
- return aa_capable(&tracer->label, CAP_SYS_PTRACE, 1);
+ return xcheck_labels_profiles(tracer, tracee, cross_ptrace_perm,
+ request, &sa);
}
-/**
- * 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)
-{
- /*
- * 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_label *tracer_l = aa_get_task_label(tracer);
- int error = 0;
-
- if (!unconfined(tracer_l)) {
- struct aa_label *tracee_l = aa_get_task_label(tracee);
-
- error = aa_may_ptrace(labels_profile(tracer_l),
- labels_profile(tracee_l),
- mode);
- error = aa_audit_ptrace(labels_profile(tracer_l),
- labels_profile(tracee_l),
- error);
-
- aa_put_label(tracee_l);
- }
- aa_put_label(tracer_l);
-
- return error;
-}
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index c3e98f74268f..bf28b48bf6dd 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -104,12 +104,31 @@ static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
static int apparmor_ptrace_access_check(struct task_struct *child,
unsigned int mode)
{
- return aa_ptrace(current, child, mode);
+ struct aa_label *tracer, *tracee;
+ int error;
+
+ tracer = begin_current_label_crit_section();
+ tracee = aa_get_task_label(child);
+ error = aa_may_ptrace(tracer, tracee,
+ mode == PTRACE_MODE_READ ? AA_PTRACE_READ : AA_PTRACE_TRACE);
+ aa_put_label(tracee);
+ end_current_label_crit_section(tracer);
+
+ return error;
}
static int apparmor_ptrace_traceme(struct task_struct *parent)
{
- return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
+ struct aa_label *tracer, *tracee;
+ int error;
+
+ tracee = begin_current_label_crit_section();
+ tracer = aa_get_task_label(parent);
+ error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE);
+ aa_put_label(tracer);
+ end_current_label_crit_section(tracee);
+
+ return error;
}
/* Derived from security/commoncap.c:cap_capget */
--
2.12.3