1 files changed, 123 insertions, 43 deletions

diff --git a/security/apparmor/capability.c b/security/apparmor/capability.c
index 887a5e948945..b9ea6bc45c1a 100644
--- a/security/apparmor/capability.c
+++ b/security/apparmor/capability.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * AppArmor security module
  *
@@ -5,20 +6,17 @@
  *
  * Copyright (C) 1998-2008 Novell/SUSE
  * Copyright 2009-2010 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/capability.h>
 #include <linux/errno.h>
 #include <linux/gfp.h>
+#include <linux/security.h>
+#include <linux/timekeeping.h>
 
 #include "include/apparmor.h"
 #include "include/capability.h"
-#include "include/context.h"
+#include "include/cred.h"
 #include "include/policy.h"
 #include "include/audit.h"
 
@@ -27,61 +25,66 @@
  */
 #include "capability_names.h"
 
+struct aa_sfs_entry aa_sfs_entry_caps[] = {
+	AA_SFS_FILE_STRING("mask", AA_SFS_CAPS_MASK),
+	AA_SFS_FILE_BOOLEAN("extended", 1),
+	{ }
+};
+
 struct audit_cache {
-	struct aa_profile *profile;
-	kernel_cap_t caps;
+	const struct cred *ad_subj_cred;
+	/* Capabilities go from 0 to CAP_LAST_CAP */
+	u64 ktime_ns_expiration[CAP_LAST_CAP+1];
 };
 
 static DEFINE_PER_CPU(struct audit_cache, audit_cache);
 
 /**
  * audit_cb - call back for capability components of audit struct
- * @ab - audit buffer   (NOT NULL)
- * @va - audit struct to audit data from  (NOT NULL)
+ * @ab: audit buffer   (NOT NULL)
+ * @va: audit struct to audit data from  (NOT NULL)
  */
 static void audit_cb(struct audit_buffer *ab, void *va)
 {
 	struct common_audit_data *sa = va;
+
 	audit_log_format(ab, " capname=");
 	audit_log_untrustedstring(ab, capability_names[sa->u.cap]);
 }
 
 /**
  * audit_caps - audit a capability
- * @profile: profile confining task (NOT NULL)
- * @task: task capability test was performed against (NOT NULL)
+ * @ad: audit data
+ * @profile: profile being tested for confinement (NOT NULL)
  * @cap: capability tested
  * @error: error code returned by test
  *
  * Do auditing of capability and handle, audit/complain/kill modes switching
  * and duplicate message elimination.
  *
- * Returns: 0 or sa->error on success,  error code on failure
+ * Returns: 0 or ad->error on success,  error code on failure
  */
-static int audit_caps(struct aa_profile *profile, struct task_struct *task,
+static int audit_caps(struct apparmor_audit_data *ad, struct aa_profile *profile,
 		      int cap, int error)
 {
+	const u64 AUDIT_CACHE_TIMEOUT_NS = 1000*1000*1000; /* 1 second */
+
+	struct aa_ruleset *rules = profile->label.rules[0];
 	struct audit_cache *ent;
 	int type = AUDIT_APPARMOR_AUTO;
-	struct common_audit_data sa;
-	struct apparmor_audit_data aad = {0,};
-	sa.type = LSM_AUDIT_DATA_CAP;
-	sa.aad = &aad;
-	sa.u.cap = cap;
-	sa.aad->tsk = task;
-	sa.aad->op = OP_CAPABLE;
-	sa.aad->error = error;
+
+	ad->error = error;
 
 	if (likely(!error)) {
 		/* test if auditing is being forced */
 		if (likely((AUDIT_MODE(profile) != AUDIT_ALL) &&
-			   !cap_raised(profile->caps.audit, cap)))
+			   !cap_raised(rules->caps.audit, cap)))
 			return 0;
 		type = AUDIT_APPARMOR_AUDIT;
 	} else if (KILL_MODE(profile) ||
-		   cap_raised(profile->caps.kill, cap)) {
+		   cap_raised(rules->caps.kill, cap)) {
 		type = AUDIT_APPARMOR_KILL;
-	} else if (cap_raised(profile->caps.quiet, cap) &&
+	} else if (cap_raised(rules->caps.quiet, cap) &&
 		   AUDIT_MODE(profile) != AUDIT_NOQUIET &&
 		   AUDIT_MODE(profile) != AUDIT_ALL) {
 		/* quiet auditing */
@@ -90,54 +93,131 @@ static int audit_caps(struct aa_profile *profile, struct task_struct *task,
 
 	/* Do simple duplicate message elimination */
 	ent = &get_cpu_var(audit_cache);
-	if (profile == ent->profile && cap_raised(ent->caps, cap)) {
+	/* If the capability was never raised the timestamp check would also catch that */
+	if (ad->subj_cred == ent->ad_subj_cred && ktime_get_ns() <= ent->ktime_ns_expiration[cap]) {
 		put_cpu_var(audit_cache);
 		if (COMPLAIN_MODE(profile))
 			return complain_error(error);
 		return error;
 	} else {
-		aa_put_profile(ent->profile);
-		ent->profile = aa_get_profile(profile);
-		cap_raise(ent->caps, cap);
+		put_cred(ent->ad_subj_cred);
+		ent->ad_subj_cred = get_cred(ad->subj_cred);
+		ent->ktime_ns_expiration[cap] = ktime_get_ns() + AUDIT_CACHE_TIMEOUT_NS;
 	}
 	put_cpu_var(audit_cache);
 
-	return aa_audit(type, profile, GFP_ATOMIC, &sa, audit_cb);
+	return aa_audit(type, profile, ad, audit_cb);
 }
 
 /**
  * profile_capable - test if profile allows use of capability @cap
  * @profile: profile being enforced    (NOT NULL, NOT unconfined)
  * @cap: capability to test if allowed
+ * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated
+ * @ad: audit data (NOT NULL)
  *
  * Returns: 0 if allowed else -EPERM
  */
-static int profile_capable(struct aa_profile *profile, int cap)
+static int profile_capable(struct aa_profile *profile, int cap,
+			   unsigned int opts, struct apparmor_audit_data *ad)
 {
-	return cap_raised(profile->caps.allow, cap) ? 0 : -EPERM;
+	struct aa_ruleset *rules = profile->label.rules[0];
+	aa_state_t state;
+	int error;
+
+	state = RULE_MEDIATES(rules, ad->class);
+	if (state) {
+		struct aa_perms perms = { };
+		u32 request;
+
+		/* caps broken into 256 x 32 bit permission chunks */
+		state = aa_dfa_next(rules->policy->dfa, state, cap >> 5);
+		request = 1 << (cap & 0x1f);
+		perms = *aa_lookup_perms(rules->policy, state);
+		aa_apply_modes_to_perms(profile, &perms);
+
+		if (opts & CAP_OPT_NOAUDIT) {
+			if (perms.complain & request)
+				ad->info = "optional: no audit";
+			else
+				ad = NULL;
+		}
+		return aa_check_perms(profile, &perms, request, ad,
+				      audit_cb);
+	}
+
+	/* fallback to old caps mediation that doesn't support conditionals */
+	if (cap_raised(rules->caps.allow, cap) &&
+	    !cap_raised(rules->caps.denied, cap))
+		error = 0;
+	else
+		error = -EPERM;
+
+	if (opts & CAP_OPT_NOAUDIT) {
+		if (!COMPLAIN_MODE(profile))
+			return error;
+		/* audit the cap request in complain mode but note that it
+		 * should be optional.
+		 */
+		ad->info = "optional: no audit";
+	}
+
+	return audit_caps(ad, profile, cap, error);
 }
 
 /**
  * aa_capable - test permission to use capability
- * @task: task doing capability test against (NOT NULL)
- * @profile: profile confining @task (NOT NULL)
+ * @subj_cred: cred we are testing capability against
+ * @label: label being tested for capability (NOT NULL)
  * @cap: capability to be tested
- * @audit: whether an audit record should be generated
+ * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated
  *
  * Look up capability in profile capability set.
  *
  * Returns: 0 on success, or else an error code.
  */
-int aa_capable(struct task_struct *task, struct aa_profile *profile, int cap,
-	       int audit)
+int aa_capable(const struct cred *subj_cred, struct aa_label *label,
+	       int cap, unsigned int opts)
 {
-	int error = profile_capable(profile, cap);
+	struct aa_profile *profile;
+	int error = 0;
+	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_CAP, AA_CLASS_CAP, OP_CAPABLE);
 
-	if (!audit) {
-		if (COMPLAIN_MODE(profile))
-			return complain_error(error);
-		return error;
+	ad.subj_cred = subj_cred;
+	ad.common.u.cap = cap;
+	error = fn_for_each_confined(label, profile,
+			profile_capable(profile, cap, opts, &ad));
+
+	return error;
+}
+
+kernel_cap_t aa_profile_capget(struct aa_profile *profile)
+{
+	struct aa_ruleset *rules = profile->label.rules[0];
+	aa_state_t state;
+
+	state = RULE_MEDIATES(rules, AA_CLASS_CAP);
+	if (state) {
+		kernel_cap_t caps = CAP_EMPTY_SET;
+		int i;
+
+		/* caps broken into up to 256, 32 bit permission chunks */
+		for (i = 0; i < (CAP_LAST_CAP >> 5); i++) {
+			struct aa_perms perms = { };
+			aa_state_t tmp;
+
+			tmp = aa_dfa_next(rules->policy->dfa, state, i);
+			perms = *aa_lookup_perms(rules->policy, tmp);
+			aa_apply_modes_to_perms(profile, &perms);
+			caps.val |= ((u64)(perms.allow)) << (i * 5);
+			caps.val |= ((u64)(perms.complain)) << (i * 5);
+		}
+		return caps;
 	}
 
-	return audit_caps(profile, task, cap, error);
+	/* fallback to old caps */
+	if (COMPLAIN_MODE(profile))
+		return CAP_FULL_SET;
+
+	return rules->caps.allow;
 }