apparmor: move ptrace checks to using labels (b2d09ae4) · Commits · e / devices / android_kernel_oneplus_sm7250

security/apparmor/domain.c

+10 −7

Original line number	Diff line number	Diff line
		@@ -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;

security/apparmor/include/apparmor.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

security/apparmor/include/ipc.h

+5 −5

Original line number	Diff line number	Diff line
		@@ -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 */

security/apparmor/ipc.c

+21 −66

Original line number	Diff line number	Diff line
		@@ -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;
		}

security/apparmor/lsm.c

+21 −2

Original line number	Diff line number	Diff line
		@@ -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 */