diff options
Diffstat (limited to 'security/apparmor/ipc.c')
| -rw-r--r-- | security/apparmor/ipc.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c new file mode 100644 index 000000000..fe36d112a --- /dev/null +++ b/security/apparmor/ipc.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AppArmor security module + * + * This file contains AppArmor ipc mediation + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2017 Canonical Ltd. + */ + +#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 + * @mask: permission mask to convert + * + * Returns: pointer to static string + */ +static const char *audit_ptrace_mask(u32 mask) +{ + switch (mask) { + case MAY_READ: + return "read"; + case MAY_WRITE: + return "trace"; + case AA_MAY_BE_READ: + return "readby"; + case AA_MAY_BE_TRACED: + return "tracedby"; + } + return ""; +} + +/* 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=\"%s\"", + audit_ptrace_mask(aad(sa)->request)); + + if (aad(sa)->denied & AA_PTRACE_PERM_MASK) { + audit_log_format(ab, " denied_mask=\"%s\"", + audit_ptrace_mask(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_signal_mask - convert mask to permission string + * @mask: permission mask to convert + * + * Returns: pointer to static string + */ +static const char *audit_signal_mask(u32 mask) +{ + if (mask & MAY_READ) + return "receive"; + if (mask & MAY_WRITE) + return "send"; + return ""; +} + +/** + * 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=\"%s\"", + audit_signal_mask(aad(sa)->request)); + if (aad(sa)->denied & AA_SIGNAL_PERM_MASK) { + audit_log_format(ab, " denied_mask=\"%s\"", + audit_signal_mask(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)); +} |