Merge tag 'apparmor-pr-2018-06-13' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull AppArmor updates from John Johansen:
"Features
- add support for mapping secids and using secctxes
- add the ability to get a task's secid
- add support for audit rule filtering

Cleanups:
- multiple typo fixes
- Convert to use match_string() helper
- update git and wiki locations in AppArmor docs
- improve get_buffers macro by using get_cpu_ptr
- Use an IDR to allocate apparmor secids

Bug fixes:
- fix '*seclen' is never less than zero
- fix mediation of prlimit
- fix memory leak when deduping profile load
- fix ptrace read check
- fix memory leak of rule on error exit path"

* tag 'apparmor-pr-2018-06-13' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor: (21 commits)
apparmor: fix ptrace read check
apparmor: fix memory leak when deduping profile load
apparmor: fix mediation of prlimit
apparmor: fixup secid map conversion to using IDR
apparmor: Use an IDR to allocate apparmor secids
apparmor: Fix memory leak of rule on error exit path
apparmor: modify audit rule support to support profile stacks
apparmor: Add support for audit rule filtering
apparmor: update git and wiki locations in AppArmor docs
apparmor: Convert to use match_string() helper
apparmor: improve get_buffers macro by using get_cpu_ptr
apparmor: fix '*seclen' is never less than zero
apparmor: fix typo "preconfinement"
apparmor: fix typo "independent"
apparmor: fix typo "traverse"
apparmor: fix typo "type"
apparmor: fix typo "replace"
apparmor: fix typo "comparison"
apparmor: fix typo "loosen"
apparmor: add the ability to get a task's secid
...

Documentation/admin-guide/LSM/apparmor.rst

···
 
 Mailing List - [e-mail]
 
-Wiki - http://apparmor.wiki.kernel.org/
+Wiki - http://wiki.apparmor.net
 
-User space tools - https://launchpad.net/apparmor
+User space tools - https://gitlab.com/apparmor
 
-Kernel module - git://git.kernel.org/pub/scm/linux/kernel/git/jj/apparmor-dev.git
+Kernel module - git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

security/apparmor/audit.c

···
 #include "include/audit.h"
 #include "include/policy.h"
 #include "include/policy_ns.h"
-
+#include "include/secid.h"
 
 const char *const audit_mode_names[] = {
 	"normal",
···
 		return complain_error(aad(sa)->error);
 
 	return aad(sa)->error;
+}
+
+struct aa_audit_rule {
+	struct aa_label *label;
+};
+
+void aa_audit_rule_free(void *vrule)
+{
+	struct aa_audit_rule *rule = vrule;
+
+	if (rule) {
+		if (!IS_ERR(rule->label))
+			aa_put_label(rule->label);
+		kfree(rule);
+	}
+}
+
+int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
+{
+	struct aa_audit_rule *rule;
+
+	switch (field) {
+	case AUDIT_SUBJ_ROLE:
+		if (op != Audit_equal && op != Audit_not_equal)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	rule = kzalloc(sizeof(struct aa_audit_rule), GFP_KERNEL);
+
+	if (!rule)
+		return -ENOMEM;
+
+	/* Currently rules are treated as coming from the root ns */
+	rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
+				     GFP_KERNEL, true, false);
+	if (IS_ERR(rule->label)) {
+		aa_audit_rule_free(rule);
+		return PTR_ERR(rule->label);
+	}
+
+	*vrule = rule;
+	return 0;
+}
+
+int aa_audit_rule_known(struct audit_krule *rule)
+{
+	int i;
+
+	for (i = 0; i < rule->field_count; i++) {
+		struct audit_field *f = &rule->fields[i];
+
+		switch (f->type) {
+		case AUDIT_SUBJ_ROLE:
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
+			struct audit_context *actx)
+{
+	struct aa_audit_rule *rule = vrule;
+	struct aa_label *label;
+	int found = 0;
+
+	label = aa_secid_to_label(sid);
+
+	if (!label)
+		return -ENOENT;
+
+	if (aa_label_is_subset(label, rule->label))
+		found = 1;
+
+	switch (field) {
+	case AUDIT_SUBJ_ROLE:
+		switch (op) {
+		case Audit_equal:
+			return found;
+		case Audit_not_equal:
+			return !found;
+		}
+	}
+	return 0;
 }

security/apparmor/domain.c

···
 						   cond, unsafe));
 
 	} else {
-		/* TODO: determine how much we want to losen this */
+		/* TODO: determine how much we want to loosen this */
 		error = fn_for_each_in_ns(label, profile,
 				profile_onexec(profile, onexec, stack, bprm,
 					       buffer, cond, unsafe));

security/apparmor/include/audit.h

···
 	return error;
 }
 
+void aa_audit_rule_free(void *vrule);
+int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule);
+int aa_audit_rule_known(struct audit_krule *rule);
+int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
+			struct audit_context *actx);
+
 #endif /* __AA_AUDIT_H */

security/apparmor/include/label.h

···
 
 void aa_label_free(struct aa_label *label);
 void aa_label_kref(struct kref *kref);
-bool aa_label_init(struct aa_label *label, int size);
+bool aa_label_init(struct aa_label *label, int size, gfp_t gfp);
 struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp);
 
 bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub);

security/apparmor/include/path.h

···
 
 DECLARE_PER_CPU(struct aa_buffers, aa_buffers);
 
-#define ASSIGN(FN, X, N) ((X) = FN(N))
-#define EVAL1(FN, X) ASSIGN(FN, X, 0) /*X = FN(0)*/
-#define EVAL2(FN, X, Y...) do { ASSIGN(FN, X, 1);  EVAL1(FN, Y); } while (0)
-#define EVAL(FN, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, X)
+#define ASSIGN(FN, A, X, N) ((X) = FN(A, N))
+#define EVAL1(FN, A, X) ASSIGN(FN, A, X, 0) /*X = FN(0)*/
+#define EVAL2(FN, A, X, Y...)	\
+	do { ASSIGN(FN, A, X, 1);  EVAL1(FN, A, Y); } while (0)
+#define EVAL(FN, A, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, A, X)
 
 #define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++)
 
···
 #define AA_BUG_PREEMPT_ENABLED(X) /* nop */
 #endif
 
-#define __get_buffer(N) ({					\
-	struct aa_buffers *__cpu_var; \
+#define __get_buffer(C, N) ({						\
 	AA_BUG_PREEMPT_ENABLED("__get_buffer without preempt disabled");  \
-	__cpu_var = this_cpu_ptr(&aa_buffers);			\
-	__cpu_var->buf[(N)]; })
+	(C)->buf[(N)]; })
 
-#define __get_buffers(X...)    EVAL(__get_buffer, X)
+#define __get_buffers(C, X...)    EVAL(__get_buffer, C, X)
 
 #define __put_buffers(X, Y...) ((void)&(X))
 
-#define get_buffers(X...)	\
-do {				\
-	preempt_disable();	\
-	__get_buffers(X);	\
+#define get_buffers(X...)						\
+do {									\
+	struct aa_buffers *__cpu_var = get_cpu_ptr(&aa_buffers);	\
+	__get_buffers(__cpu_var, X);					\
 } while (0)
 
-#define put_buffers(X, Y...)	\
-do {				\
-	__put_buffers(X, Y);	\
-	preempt_enable();	\
+#define put_buffers(X, Y...)		\
+do {					\
+	__put_buffers(X, Y);		\
+	put_cpu_ptr(&aa_buffers);	\
 } while (0)
 
 #endif /* __AA_PATH_H */

security/apparmor/include/secid.h

···
  *
  * This file contains AppArmor security identifier (secid) definitions
  *
- * Copyright 2009-2010 Canonical Ltd.
+ * Copyright 2009-2018 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
···
 #ifndef __AA_SECID_H
 #define __AA_SECID_H
 
+#include <linux/slab.h>
 #include <linux/types.h>
+
+struct aa_label;
 
 /* secid value that will not be allocated */
 #define AA_SECID_INVALID 0
-#define AA_SECID_ALLOC AA_SECID_INVALID
 
-u32 aa_alloc_secid(void);
+struct aa_label *aa_secid_to_label(u32 secid);
+int apparmor_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
+int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
+void apparmor_release_secctx(char *secdata, u32 seclen);
+
+
+int aa_alloc_secid(struct aa_label *label, gfp_t gfp);
 void aa_free_secid(u32 secid);
+void aa_secid_update(u32 secid, struct aa_label *label);
+
+void aa_secids_init(void);
 
 #endif /* __AA_SECID_H */

security/apparmor/label.c

···
 }
 
 /**
- * profile_cmp - profile comparision for set ordering
+ * profile_cmp - profile comparison for set ordering
  * @a: profile to compare (NOT NULL)
  * @b: profile to compare (NOT NULL)
  *
···
 }
 
 /**
- * vec_cmp - label comparision for set ordering
+ * vec_cmp - label comparison for set ordering
  * @a: label to compare (NOT NULL)
  * @vec: vector of profiles to compare (NOT NULL)
  * @n: length of @vec
···
 		aa_put_label(new);
 }
 
-bool aa_label_init(struct aa_label *label, int size)
+bool aa_label_init(struct aa_label *label, int size, gfp_t gfp)
 {
 	AA_BUG(!label);
 	AA_BUG(size < 1);
 
-	label->secid = aa_alloc_secid();
-	if (label->secid == AA_SECID_INVALID)
+	if (aa_alloc_secid(label, gfp) < 0)
 		return false;
 
 	label->size = size;			/* doesn't include null */
···
 	if (!new)
 		goto fail;
 
-	if (!aa_label_init(new, size))
+	if (!aa_label_init(new, size, gfp))
 		goto fail;
 
 	if (!proxy) {
···
 
 
 /**
- * label_cmp - label comparision for set ordering
+ * label_cmp - label comparison for set ordering
  * @a: label to compare (NOT NULL)
  * @b: label to compare (NOT NULL)
  *
···
 
 /**
  * __label_update - insert updated version of @label into labelset
- * @label - the label to update/repace
+ * @label - the label to update/replace
  *
  * Returns: new label that is up to date
  *     else NULL on failure

security/apparmor/lib.c

···
  * @request: requested perms
  * @deny: Returns: explicit deny set
  * @sa: initialized audit structure (MAY BE NULL if not auditing)
- * @cb: callback fn for tpye specific fields (MAY BE NULL)
+ * @cb: callback fn for type specific fields (MAY BE NULL)
  *
  * Returns: 0 if permission else error code
  *

security/apparmor/lsm.c

···
 #include "include/policy_ns.h"
 #include "include/procattr.h"
 #include "include/mount.h"
+#include "include/secid.h"
 
 /* Flag indicating whether initialization completed */
 int apparmor_initialized;
···
 	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);
+			(mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
+						  : AA_PTRACE_TRACE);
 	aa_put_label(tracee);
 	end_current_label_crit_section(tracer);
 
···
 	return;
 }
 
+static void apparmor_task_getsecid(struct task_struct *p, u32 *secid)
+{
+	struct aa_label *label = aa_get_task_label(p);
+	*secid = label->secid;
+	aa_put_label(label);
+}
+
 static int apparmor_task_setrlimit(struct task_struct *task,
 		unsigned int resource, struct rlimit *new_rlim)
 {
···
 
 	LSM_HOOK_INIT(task_free, apparmor_task_free),
 	LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
+	LSM_HOOK_INIT(task_getsecid, apparmor_task_getsecid),
 	LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
 	LSM_HOOK_INIT(task_kill, apparmor_task_kill),
+
+#ifdef CONFIG_AUDIT
+	LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
+	LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
+	LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
+	LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
+#endif
+
+	LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
+	LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
+	LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
 };
 
 /*
···
 	if (apparmor_initialized && !policy_admin_capable(NULL))
 		return -EPERM;
 
-	for (i = 0; i < AUDIT_MAX_INDEX; i++) {
-		if (strcmp(val, audit_mode_names[i]) == 0) {
-			aa_g_audit = i;
-			return 0;
-		}
-	}
+	i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
+	if (i < 0)
+		return -EINVAL;
 
-	return -EINVAL;
+	aa_g_audit = i;
+	return 0;
 }
 
 static int param_get_mode(char *buffer, const struct kernel_param *kp)
···
 	if (apparmor_initialized && !policy_admin_capable(NULL))
 		return -EPERM;
 
-	for (i = 0; i < APPARMOR_MODE_NAMES_MAX_INDEX; i++) {
-		if (strcmp(val, aa_profile_mode_names[i]) == 0) {
-			aa_g_profile_mode = i;
-			return 0;
-		}
-	}
+	i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
+			 val);
+	if (i < 0)
+		return -EINVAL;
 
-	return -EINVAL;
+	aa_g_profile_mode = i;
+	return 0;
 }
 
 /*
···
 		apparmor_enabled = false;
 		return 0;
 	}
+
+	aa_secids_init();
 
 	error = aa_setup_dfa_engine();
 	if (error) {

security/apparmor/match.c

···
 
 /**
  * aa_dfa_next - step one character to the next state in the dfa
- * @dfa: the dfa to tranverse (NOT NULL)
+ * @dfa: the dfa to traverse (NOT NULL)
  * @state: the state to start in
  * @c: the input character to transition on
  *

security/apparmor/mount.c

···
  * @src_name: src_name of object being mediated (MAYBE_NULL)
  * @type: type of filesystem (MAYBE_NULL)
  * @trans: name of trans (MAYBE NULL)
- * @flags: filesystem idependent mount flags
+ * @flags: filesystem independent mount flags
  * @data: filesystem mount flags
  * @request: permissions requested
  * @perms: the permissions computed for the request (NOT NULL)

security/apparmor/policy.c

···
 
 	if (!aa_policy_init(&profile->base, NULL, hname, gfp))
 		goto fail;
-	if (!aa_label_init(&profile->label, 1))
+	if (!aa_label_init(&profile->label, 1, gfp))
 		goto fail;
 
 	/* update being set needed by fs interface */
···
 			audit_policy(label, op, ns_name, ent->new->base.hname,
 				     "same as current profile, skipping",
 				     error);
+			/* break refcount cycle with proxy. */
+			aa_put_proxy(ent->new->label.proxy);
+			ent->new->label.proxy = NULL;
 			goto skip;
 		}
 
···
  * Remove a profile or sub namespace from the current namespace, so that
  * they can not be found anymore and mark them as replaced by unconfined
  *
- * NOTE: removing confinement does not restore rlimits to preconfinemnet values
+ * NOTE: removing confinement does not restore rlimits to preconfinement values
  *
  * Returns: size of data consume else error code if fails
  */

security/apparmor/resource.c

···
 	 */
 
 	if (label != peer &&
-	    !aa_capable(label, CAP_SYS_RESOURCE, SECURITY_CAP_NOAUDIT))
+	    aa_capable(label, CAP_SYS_RESOURCE, SECURITY_CAP_NOAUDIT) != 0)
 		error = fn_for_each(label, profile,
 				audit_resource(profile, resource,
 					       new_rlim->rlim_max, peer,

security/apparmor/secid.c

···
  *
  * This file contains AppArmor security identifier (secid) manipulation fns
  *
- * 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
···
  * License.
  *
  *
- * AppArmor allocates a unique secid for every profile loaded.  If a profile
- * is replaced it receives the secid of the profile it is replacing.
- *
- * The secid value of 0 is invalid.
+ * AppArmor allocates a unique secid for every label used. If a label
+ * is replaced it receives the secid of the label it is replacing.
  */
 
-#include <linux/spinlock.h>
 #include <linux/errno.h>
 #include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
 
+#include "include/cred.h"
+#include "include/lib.h"
 #include "include/secid.h"
+#include "include/label.h"
+#include "include/policy_ns.h"
 
-/* global counter from which secids are allocated */
-static u32 global_secid;
+/*
+ * secids - do not pin labels with a refcount. They rely on the label
+ * properly updating/freeing them
+ */
+
+#define AA_FIRST_SECID 1
+
+static DEFINE_IDR(aa_secids);
 static DEFINE_SPINLOCK(secid_lock);
 
-/* TODO FIXME: add secid to profile mapping, and secid recycling */
+/*
+ * TODO: allow policy to reserve a secid range?
+ * TODO: add secid pinning
+ * TODO: use secid_update in label replace
+ */
+
+/**
+ * aa_secid_update - update a secid mapping to a new label
+ * @secid: secid to update
+ * @label: label the secid will now map to
+ */
+void aa_secid_update(u32 secid, struct aa_label *label)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&secid_lock, flags);
+	idr_replace(&aa_secids, label, secid);
+	spin_unlock_irqrestore(&secid_lock, flags);
+}
+
+/**
+ *
+ * see label for inverse aa_label_to_secid
+ */
+struct aa_label *aa_secid_to_label(u32 secid)
+{
+	struct aa_label *label;
+
+	rcu_read_lock();
+	label = idr_find(&aa_secids, secid);
+	rcu_read_unlock();
+
+	return label;
+}
+
+int apparmor_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+{
+	/* TODO: cache secctx and ref count so we don't have to recreate */
+	struct aa_label *label = aa_secid_to_label(secid);
+	int len;
+
+	AA_BUG(!secdata);
+	AA_BUG(!seclen);
+
+	if (!label)
+		return -EINVAL;
+
+	if (secdata)
+		len = aa_label_asxprint(secdata, root_ns, label,
+					FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
+					FLAG_HIDDEN_UNCONFINED | FLAG_ABS_ROOT,
+					GFP_ATOMIC);
+	else
+		len = aa_label_snxprint(NULL, 0, root_ns, label,
+					FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
+					FLAG_HIDDEN_UNCONFINED | FLAG_ABS_ROOT);
+	if (len < 0)
+		return -ENOMEM;
+
+	*seclen = len;
+
+	return 0;
+}
+
+int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
+{
+	struct aa_label *label;
+
+	label = aa_label_strn_parse(&root_ns->unconfined->label, secdata,
+				    seclen, GFP_KERNEL, false, false);
+	if (IS_ERR(label))
+		return PTR_ERR(label);
+	*secid = label->secid;
+
+	return 0;
+}
+
+void apparmor_release_secctx(char *secdata, u32 seclen)
+{
+	kfree(secdata);
+}
 
 /**
  * aa_alloc_secid - allocate a new secid for a profile
+ * @label: the label to allocate a secid for
+ * @gfp: memory allocation flags
+ *
+ * Returns: 0 with @label->secid initialized
+ *          <0 returns error with @label->secid set to AA_SECID_INVALID
  */
-u32 aa_alloc_secid(void)
+int aa_alloc_secid(struct aa_label *label, gfp_t gfp)
 {
-	u32 secid;
+	unsigned long flags;
+	int ret;
 
-	/*
-	 * TODO FIXME: secid recycling - part of profile mapping table
-	 */
-	spin_lock(&secid_lock);
-	secid = (++global_secid);
-	spin_unlock(&secid_lock);
-	return secid;
+	idr_preload(gfp);
+	spin_lock_irqsave(&secid_lock, flags);
+	ret = idr_alloc(&aa_secids, label, AA_FIRST_SECID, 0, GFP_ATOMIC);
+	spin_unlock_irqrestore(&secid_lock, flags);
+	idr_preload_end();
+
+	if (ret < 0) {
+		label->secid = AA_SECID_INVALID;
+		return ret;
+	}
+
+	AA_BUG(ret == AA_SECID_INVALID);
+	label->secid = ret;
+	return 0;
 }
 
 /**
···
  */
 void aa_free_secid(u32 secid)
 {
-	;			/* NOP ATM */
+	unsigned long flags;
+
+	spin_lock_irqsave(&secid_lock, flags);
+	idr_remove(&aa_secids, secid);
+	spin_unlock_irqrestore(&secid_lock, flags);
+}
+
+void aa_secids_init(void)
+{
+	idr_init_base(&aa_secids, AA_FIRST_SECID);
 }