From b2d09ae449cedc6f276ac485c013d22a97d36992 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Fri, 9 Jun 2017 14:22:14 -0700 Subject: apparmor: move ptrace checks to using labels Signed-off-by: John Johansen --- 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(-) (limited to 'security') diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 8d6797c..fab8923 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 c4a9004..aaf893f 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 288ca76..fb3e751 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 7678d94..f816493 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 c3e98f7..bf28b48 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 */ -- cgit v1.1