1 files changed, 451 insertions, 62 deletions

diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c
index fcfe0233574c..82dbb97ad406 100644
--- a/security/apparmor/lib.c
+++ b/security/apparmor/lib.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * AppArmor security module
  *
@@ -5,13 +6,9 @@
  *
  * 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/ctype.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/string.h>
@@ -19,39 +16,197 @@
 
 #include "include/audit.h"
 #include "include/apparmor.h"
+#include "include/lib.h"
+#include "include/perms.h"
+#include "include/policy.h"
+
+struct aa_perms nullperms;
+struct aa_perms allperms = { .allow = ALL_PERMS_MASK,
+			     .quiet = ALL_PERMS_MASK,
+			     .hide = ALL_PERMS_MASK };
+
+struct val_table_ent {
+	const char *str;
+	int value;
+};
+
+static struct val_table_ent debug_values_table[] = {
+	{ "N", DEBUG_NONE },
+	{ "none", DEBUG_NONE },
+	{ "n", DEBUG_NONE },
+	{ "0", DEBUG_NONE },
+	{ "all", DEBUG_ALL },
+	{ "Y", DEBUG_ALL },
+	{ "y", DEBUG_ALL },
+	{ "1", DEBUG_ALL },
+	{ "abs_root", DEBUG_LABEL_ABS_ROOT },
+	{ "label", DEBUG_LABEL },
+	{ "domain", DEBUG_DOMAIN },
+	{ "policy", DEBUG_POLICY },
+	{ "interface", DEBUG_INTERFACE },
+	{ NULL, 0 }
+};
 
+static struct val_table_ent *val_table_find_ent(struct val_table_ent *table,
+						const char *name, size_t len)
+{
+	struct val_table_ent *entry;
+
+	for (entry = table; entry->str != NULL; entry++) {
+		if (strncmp(entry->str, name, len) == 0 &&
+		    strlen(entry->str) == len)
+			return entry;
+	}
+	return NULL;
+}
+
+int aa_parse_debug_params(const char *str)
+{
+	struct val_table_ent *ent;
+	const char *next;
+	int val = 0;
+
+	do {
+		size_t n = strcspn(str, "\r\n,");
+
+		next = str + n;
+		ent = val_table_find_ent(debug_values_table, str, next - str);
+		if (ent)
+			val |= ent->value;
+		else
+			AA_DEBUG(DEBUG_INTERFACE, "unknown debug type '%.*s'",
+				 (int)(next - str), str);
+		str = next + 1;
+	} while (*next != 0);
+	return val;
+}
 
 /**
- * aa_split_fqname - split a fqname into a profile and namespace name
- * @fqname: a full qualified name in namespace profile format (NOT NULL)
- * @ns_name: pointer to portion of the string containing the ns name (NOT NULL)
- *
- * Returns: profile name or NULL if one is not specified
- *
- * Split a namespace name from a profile name (see policy.c for naming
- * description).  If a portion of the name is missing it returns NULL for
- * that portion.
+ * val_mask_to_str - convert a perm mask to its short string
+ * @str: character buffer to store string in (at least 10 characters)
+ * @size: size of the @str buffer
+ * @table: NUL-terminated character buffer of permission characters (NOT NULL)
+ * @mask: permission mask to convert
+ */
+static int val_mask_to_str(char *str, size_t size,
+			   const struct val_table_ent *table, u32 mask)
+{
+	const struct val_table_ent *ent;
+	int total = 0;
+
+	for (ent = table; ent->str; ent++) {
+		if (ent->value && (ent->value & mask) == ent->value) {
+			int len = scnprintf(str, size, "%s%s", total ? "," : "",
+					    ent->str);
+			size -= len;
+			str += len;
+			total += len;
+			mask &= ~ent->value;
+		}
+	}
+
+	return total;
+}
+
+int aa_print_debug_params(char *buffer)
+{
+	if (!aa_g_debug)
+		return sprintf(buffer, "N");
+	return val_mask_to_str(buffer, PAGE_SIZE, debug_values_table,
+			       aa_g_debug);
+}
+
+bool aa_resize_str_table(struct aa_str_table *t, int newsize, gfp_t gfp)
+{
+	char **n;
+	int i;
+
+	if (t->size == newsize)
+		return true;
+	n = kcalloc(newsize, sizeof(*n), gfp);
+	if (!n)
+		return false;
+	for (i = 0; i < min(t->size, newsize); i++)
+		n[i] = t->table[i];
+	for (; i < t->size; i++)
+		kfree_sensitive(t->table[i]);
+	if (newsize > t->size)
+		memset(&n[t->size], 0, (newsize-t->size)*sizeof(*n));
+	kfree_sensitive(t->table);
+	t->table = n;
+	t->size = newsize;
+
+	return true;
+}
+
+/**
+ * aa_free_str_table - free entries str table
+ * @t: the string table to free  (MAYBE NULL)
+ */
+void aa_free_str_table(struct aa_str_table *t)
+{
+	int i;
+
+	if (t) {
+		if (!t->table)
+			return;
+
+		for (i = 0; i < t->size; i++)
+			kfree_sensitive(t->table[i]);
+		kfree_sensitive(t->table);
+		t->table = NULL;
+		t->size = 0;
+	}
+}
+
+/**
+ * skipn_spaces - Removes leading whitespace from @str.
+ * @str: The string to be stripped.
+ * @n: length of str to parse, will stop at \0 if encountered before n
  *
- * NOTE: may modify the @fqname string.  The pointers returned point
- *       into the @fqname string.
+ * Returns a pointer to the first non-whitespace character in @str.
+ * if all whitespace will return NULL
  */
-char *aa_split_fqname(char *fqname, char **ns_name)
+
+const char *skipn_spaces(const char *str, size_t n)
 {
-	char *name = strim(fqname);
+	for (; n && isspace(*str); --n)
+		++str;
+	if (n)
+		return (char *)str;
+	return NULL;
+}
+
+const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name,
+			     size_t *ns_len)
+{
+	const char *end = fqname + n;
+	const char *name = skipn_spaces(fqname, n);
 
 	*ns_name = NULL;
+	*ns_len = 0;
+
+	if (!name)
+		return NULL;
+
 	if (name[0] == ':') {
-		char *split = strchr(&name[1], ':');
-		*ns_name = skip_spaces(&name[1]);
+		char *split = strnchr(&name[1], end - &name[1], ':');
+		*ns_name = skipn_spaces(&name[1], end - &name[1]);
+		if (!*ns_name)
+			return NULL;
 		if (split) {
-			/* overwrite ':' with \0 */
-			*split++ = 0;
-			if (strncmp(split, "//", 2) == 0)
+			*ns_len = split - *ns_name;
+			if (*ns_len == 0)
+				*ns_name = NULL;
+			split++;
+			if (end - split > 1 && strncmp(split, "//", 2) == 0)
 				split += 2;
-			name = skip_spaces(split);
-		} else
+			name = skipn_spaces(split, end - split);
+		} else {
 			/* a ns name without a following profile is allowed */
 			name = NULL;
+			*ns_len = end - *ns_name;
+		}
 	}
 	if (name && *name == 0)
 		name = NULL;
@@ -66,60 +221,294 @@ char *aa_split_fqname(char *fqname, char **ns_name)
 void aa_info_message(const char *str)
 {
 	if (audit_enabled) {
-		struct common_audit_data sa;
-		struct apparmor_audit_data aad = {0,};
-		sa.type = LSM_AUDIT_DATA_NONE;
-		sa.aad = &aad;
-		aad.info = str;
-		aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
+		DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE, NULL);
+
+		ad.info = str;
+		aa_audit_msg(AUDIT_APPARMOR_STATUS, &ad, NULL);
 	}
 	printk(KERN_INFO "AppArmor: %s\n", str);
 }
 
+__counted char *aa_str_alloc(int size, gfp_t gfp)
+{
+	struct counted_str *str;
+
+	str = kmalloc(struct_size(str, name, size), gfp);
+	if (!str)
+		return NULL;
+
+	kref_init(&str->count);
+	return str->name;
+}
+
+void aa_str_kref(struct kref *kref)
+{
+	kfree(container_of(kref, struct counted_str, count));
+}
+
+
+const char aa_file_perm_chrs[] = "xwracd         km l     ";
+const char *aa_file_perm_names[] = {
+	"exec",
+	"write",
+	"read",
+	"append",
+
+	"create",
+	"delete",
+	"open",
+	"rename",
+
+	"setattr",
+	"getattr",
+	"setcred",
+	"getcred",
+
+	"chmod",
+	"chown",
+	"chgrp",
+	"lock",
+
+	"mmap",
+	"mprot",
+	"link",
+	"snapshot",
+
+	"unknown",
+	"unknown",
+	"unknown",
+	"unknown",
+
+	"unknown",
+	"unknown",
+	"unknown",
+	"unknown",
+
+	"stack",
+	"change_onexec",
+	"change_profile",
+	"change_hat",
+};
+
+/**
+ * aa_perm_mask_to_str - convert a perm mask to its short string
+ * @str: character buffer to store string in (at least 10 characters)
+ * @str_size: size of the @str buffer
+ * @chrs: NUL-terminated character buffer of permission characters
+ * @mask: permission mask to convert
+ */
+void aa_perm_mask_to_str(char *str, size_t str_size, const char *chrs, u32 mask)
+{
+	unsigned int i, perm = 1;
+	size_t num_chrs = strlen(chrs);
+
+	for (i = 0; i < num_chrs; perm <<= 1, i++) {
+		if (mask & perm) {
+			/* Ensure that one byte is left for NUL-termination */
+			if (WARN_ON_ONCE(str_size <= 1))
+				break;
+
+			*str++ = chrs[i];
+			str_size--;
+		}
+	}
+	*str = '\0';
+}
+
+void aa_audit_perm_names(struct audit_buffer *ab, const char * const *names,
+			 u32 mask)
+{
+	const char *fmt = "%s";
+	unsigned int i, perm = 1;
+	bool prev = false;
+
+	for (i = 0; i < 32; perm <<= 1, i++) {
+		if (mask & perm) {
+			audit_log_format(ab, fmt, names[i]);
+			if (!prev) {
+				prev = true;
+				fmt = " %s";
+			}
+		}
+	}
+}
+
+void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs,
+			u32 chrsmask, const char * const *names, u32 namesmask)
+{
+	char str[33];
+
+	audit_log_format(ab, "\"");
+	if ((mask & chrsmask) && chrs) {
+		aa_perm_mask_to_str(str, sizeof(str), chrs, mask & chrsmask);
+		mask &= ~chrsmask;
+		audit_log_format(ab, "%s", str);
+		if (mask & namesmask)
+			audit_log_format(ab, " ");
+	}
+	if ((mask & namesmask) && names)
+		aa_audit_perm_names(ab, names, mask & namesmask);
+	audit_log_format(ab, "\"");
+}
+
+/**
+ * aa_apply_modes_to_perms - apply namespace and profile flags to perms
+ * @profile: that perms where computed from
+ * @perms: perms to apply mode modifiers to
+ *
+ * TODO: split into profile and ns based flags for when accumulating perms
+ */
+void aa_apply_modes_to_perms(struct aa_profile *profile, struct aa_perms *perms)
+{
+	switch (AUDIT_MODE(profile)) {
+	case AUDIT_ALL:
+		perms->audit = ALL_PERMS_MASK;
+		fallthrough;
+	case AUDIT_NOQUIET:
+		perms->quiet = 0;
+		break;
+	case AUDIT_QUIET:
+		perms->audit = 0;
+		fallthrough;
+	case AUDIT_QUIET_DENIED:
+		perms->quiet = ALL_PERMS_MASK;
+		break;
+	}
+
+	if (KILL_MODE(profile))
+		perms->kill = ALL_PERMS_MASK;
+	else if (COMPLAIN_MODE(profile))
+		perms->complain = ALL_PERMS_MASK;
+	else if (USER_MODE(profile))
+		perms->prompt = ALL_PERMS_MASK;
+}
+
+void aa_profile_match_label(struct aa_profile *profile,
+			    struct aa_ruleset *rules,
+			    struct aa_label *label,
+			    int type, u32 request, struct aa_perms *perms)
+{
+	/* TODO: doesn't yet handle extended types */
+	aa_state_t state;
+
+	state = aa_dfa_next(rules->policy->dfa,
+			    rules->policy->start[AA_CLASS_LABEL],
+			    type);
+	aa_label_match(profile, rules, label, state, false, request, perms);
+}
+
+
 /**
- * __aa_kvmalloc - do allocation preferring kmalloc but falling back to vmalloc
- * @size: how many bytes of memory are required
- * @flags: the type of memory to allocate (see kmalloc).
+ * aa_check_perms - do audit mode selection based on perms set
+ * @profile: profile being checked
+ * @perms: perms computed for the request
+ * @request: requested perms
+ * @ad: initialized audit structure (MAY BE NULL if not auditing)
+ * @cb: callback fn for type specific fields (MAY BE NULL)
+ *
+ * Returns: 0 if permission else error code
  *
- * Return: allocated buffer or NULL if failed
+ * Note: profile audit modes need to be set before calling by setting the
+ *       perm masks appropriately.
  *
- * It is possible that policy being loaded from the user is larger than
- * what can be allocated by kmalloc, in those cases fall back to vmalloc.
+ *       If not auditing then complain mode is not enabled and the
+ *       error code will indicate whether there was an explicit deny
+ *	 with a positive value.
  */
-void *__aa_kvmalloc(size_t size, gfp_t flags)
+int aa_check_perms(struct aa_profile *profile, struct aa_perms *perms,
+		   u32 request, struct apparmor_audit_data *ad,
+		   void (*cb)(struct audit_buffer *, void *))
 {
-	void *buffer = NULL;
+	int type, error;
+	u32 denied = request & (~perms->allow | perms->deny);
 
-	if (size == 0)
-		return NULL;
+	if (likely(!denied)) {
+		/* mask off perms that are not being force audited */
+		request &= perms->audit;
+		if (!request || !ad)
+			return 0;
+
+		type = AUDIT_APPARMOR_AUDIT;
+		error = 0;
+	} else {
+		error = -EACCES;
 
-	/* do not attempt kmalloc if we need more than 16 pages at once */
-	if (size <= (16*PAGE_SIZE))
-		buffer = kmalloc(size, flags | GFP_NOIO | __GFP_NOWARN);
-	if (!buffer) {
-		/* see kvfree for why size must be at least work_struct size
-		 * when allocated via vmalloc
-		 */
-		if (size < sizeof(struct work_struct))
-			size = sizeof(struct work_struct);
-		if (flags & __GFP_ZERO)
-			buffer = vzalloc(size);
+		if (denied & perms->kill)
+			type = AUDIT_APPARMOR_KILL;
+		else if (denied == (denied & perms->complain))
+			type = AUDIT_APPARMOR_ALLOWED;
 		else
-			buffer = vmalloc(size);
+			type = AUDIT_APPARMOR_DENIED;
+
+		if (denied == (denied & perms->hide))
+			error = -ENOENT;
+
+		denied &= ~perms->quiet;
+		if (!ad || !denied)
+			return error;
 	}
-	return buffer;
+
+	if (ad) {
+		ad->subj_label = &profile->label;
+		ad->request = request;
+		ad->denied = denied;
+		ad->error = error;
+		aa_audit_msg(type, ad, cb);
+	}
+
+	if (type == AUDIT_APPARMOR_ALLOWED)
+		error = 0;
+
+	return error;
 }
 
+
 /**
- * kvfree - free an allocation do by kvmalloc
- * @buffer: buffer to free (MAYBE_NULL)
+ * aa_policy_init - initialize a policy structure
+ * @policy: policy to initialize  (NOT NULL)
+ * @prefix: prefix name if any is required.  (MAYBE NULL)
+ * @name: name of the policy, init will make a copy of it  (NOT NULL)
+ * @gfp: allocation mode
  *
- * Free a buffer allocated by kvmalloc
+ * Note: this fn creates a copy of strings passed in
+ *
+ * Returns: true if policy init successful
+ */
+bool aa_policy_init(struct aa_policy *policy, const char *prefix,
+		    const char *name, gfp_t gfp)
+{
+	char *hname;
+
+	/* freed by policy_free */
+	if (prefix) {
+		hname = aa_str_alloc(strlen(prefix) + strlen(name) + 3, gfp);
+		if (hname)
+			sprintf(hname, "%s//%s", prefix, name);
+	} else {
+		hname = aa_str_alloc(strlen(name) + 1, gfp);
+		if (hname)
+			strcpy(hname, name);
+	}
+	if (!hname)
+		return false;
+	policy->hname = hname;
+	/* base.name is a substring of fqname */
+	policy->name = basename(policy->hname);
+	INIT_LIST_HEAD(&policy->list);
+	INIT_LIST_HEAD(&policy->profiles);
+
+	return true;
+}
+
+/**
+ * aa_policy_destroy - free the elements referenced by @policy
+ * @policy: policy that is to have its elements freed  (NOT NULL)
  */
-void kvfree(void *buffer)
+void aa_policy_destroy(struct aa_policy *policy)
 {
-	if (is_vmalloc_addr(buffer))
-		vfree(buffer);
-	else
-		kfree(buffer);
+	AA_BUG(on_list_rcu(&policy->profiles));
+	AA_BUG(on_list_rcu(&policy->list));
+
+	/* don't free name as its a subset of hname */
+	aa_put_str(policy->hname);
 }