Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 525 insertions, 0 deletions

diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c
new file mode 100644
index 000000000..fa49b81eb
--- /dev/null
+++ b/security/apparmor/lib.c
@@ -0,0 +1,525 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AppArmor security module
+ *
+ * This file contains basic common functions used in AppArmor
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ */
+
+#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+
+#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 };
+
+/**
+ * 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.
+ *
+ * NOTE: may modify the @fqname string.  The pointers returned point
+ *       into the @fqname string.
+ */
+char *aa_split_fqname(char *fqname, char **ns_name)
+{
+	char *name = strim(fqname);
+
+	*ns_name = NULL;
+	if (name[0] == ':') {
+		char *split = strchr(&name[1], ':');
+		*ns_name = skip_spaces(&name[1]);
+		if (split) {
+			/* overwrite ':' with \0 */
+			*split++ = 0;
+			if (strncmp(split, "//", 2) == 0)
+				split += 2;
+			name = skip_spaces(split);
+		} else
+			/* a ns name without a following profile is allowed */
+			name = NULL;
+	}
+	if (name && *name == 0)
+		name = NULL;
+
+	return name;
+}
+
+/**
+ * skipn_spaces - Removes leading whitespace from @str.
+ * @str: The string to be stripped.
+ *
+ * Returns a pointer to the first non-whitespace character in @str.
+ * if all whitespace will return NULL
+ */
+
+const char *skipn_spaces(const char *str, size_t n)
+{
+	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 = strnchr(&name[1], end - &name[1], ':');
+		*ns_name = skipn_spaces(&name[1], end - &name[1]);
+		if (!*ns_name)
+			return NULL;
+		if (split) {
+			*ns_len = split - *ns_name;
+			if (*ns_len == 0)
+				*ns_name = NULL;
+			split++;
+			if (end - split > 1 && strncmp(split, "//", 2) == 0)
+				split += 2;
+			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;
+
+	return name;
+}
+
+/**
+ * aa_info_message - log a none profile related status message
+ * @str: message to log
+ */
+void aa_info_message(const char *str)
+{
+	if (audit_enabled) {
+		DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL);
+
+		aad(&sa)->info = str;
+		aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
+	}
+	printk(KERN_INFO "AppArmor: %s\n", str);
+}
+
+__counted char *aa_str_alloc(int size, gfp_t gfp)
+{
+	struct counted_str *str;
+
+	str = kmalloc(sizeof(struct counted_str) + 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_audit_perms_cb - generic callback fn for auditing perms
+ * @ab: audit buffer (NOT NULL)
+ * @va: audit struct to audit values of (NOT NULL)
+ */
+static void aa_audit_perms_cb(struct audit_buffer *ab, void *va)
+{
+	struct common_audit_data *sa = va;
+
+	if (aad(sa)->request) {
+		audit_log_format(ab, " requested_mask=");
+		aa_audit_perm_mask(ab, aad(sa)->request, aa_file_perm_chrs,
+				   PERMS_CHRS_MASK, aa_file_perm_names,
+				   PERMS_NAMES_MASK);
+	}
+	if (aad(sa)->denied) {
+		audit_log_format(ab, "denied_mask=");
+		aa_audit_perm_mask(ab, aad(sa)->denied, aa_file_perm_chrs,
+				   PERMS_CHRS_MASK, aa_file_perm_names,
+				   PERMS_NAMES_MASK);
+	}
+	audit_log_format(ab, " peer=");
+	aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
+				      FLAGS_NONE, GFP_ATOMIC);
+}
+
+/**
+ * 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;
+/*
+ *  TODO:
+ *	else if (PROMPT_MODE(profile))
+ *		perms->prompt = ALL_PERMS_MASK;
+ */
+}
+
+static u32 map_other(u32 x)
+{
+	return ((x & 0x3) << 8) |	/* SETATTR/GETATTR */
+		((x & 0x1c) << 18) |	/* ACCEPT/BIND/LISTEN */
+		((x & 0x60) << 19);	/* SETOPT/GETOPT */
+}
+
+void aa_compute_perms(struct aa_dfa *dfa, unsigned int state,
+		      struct aa_perms *perms)
+{
+	*perms = (struct aa_perms) {
+		.allow = dfa_user_allow(dfa, state),
+		.audit = dfa_user_audit(dfa, state),
+		.quiet = dfa_user_quiet(dfa, state),
+	};
+
+	/* for v5 perm mapping in the policydb, the other set is used
+	 * to extend the general perm set
+	 */
+	perms->allow |= map_other(dfa_other_allow(dfa, state));
+	perms->audit |= map_other(dfa_other_audit(dfa, state));
+	perms->quiet |= map_other(dfa_other_quiet(dfa, state));
+//	perms->xindex = dfa_user_xindex(dfa, state);
+}
+
+/**
+ * aa_perms_accum_raw - accumulate perms with out masking off overlapping perms
+ * @accum - perms struct to accumulate into
+ * @addend - perms struct to add to @accum
+ */
+void aa_perms_accum_raw(struct aa_perms *accum, struct aa_perms *addend)
+{
+	accum->deny |= addend->deny;
+	accum->allow &= addend->allow & ~addend->deny;
+	accum->audit |= addend->audit & addend->allow;
+	accum->quiet &= addend->quiet & ~addend->allow;
+	accum->kill |= addend->kill & ~addend->allow;
+	accum->stop |= addend->stop & ~addend->allow;
+	accum->complain |= addend->complain & ~addend->allow & ~addend->deny;
+	accum->cond |= addend->cond & ~addend->allow & ~addend->deny;
+	accum->hide &= addend->hide & ~addend->allow;
+	accum->prompt |= addend->prompt & ~addend->allow & ~addend->deny;
+}
+
+/**
+ * aa_perms_accum - accumulate perms, masking off overlapping perms
+ * @accum - perms struct to accumulate into
+ * @addend - perms struct to add to @accum
+ */
+void aa_perms_accum(struct aa_perms *accum, struct aa_perms *addend)
+{
+	accum->deny |= addend->deny;
+	accum->allow &= addend->allow & ~accum->deny;
+	accum->audit |= addend->audit & accum->allow;
+	accum->quiet &= addend->quiet & ~accum->allow;
+	accum->kill |= addend->kill & ~accum->allow;
+	accum->stop |= addend->stop & ~accum->allow;
+	accum->complain |= addend->complain & ~accum->allow & ~accum->deny;
+	accum->cond |= addend->cond & ~accum->allow & ~accum->deny;
+	accum->hide &= addend->hide & ~accum->allow;
+	accum->prompt |= addend->prompt & ~accum->allow & ~accum->deny;
+}
+
+void aa_profile_match_label(struct aa_profile *profile, struct aa_label *label,
+			    int type, u32 request, struct aa_perms *perms)
+{
+	/* TODO: doesn't yet handle extended types */
+	unsigned int state;
+
+	state = aa_dfa_next(profile->policy.dfa,
+			    profile->policy.start[AA_CLASS_LABEL],
+			    type);
+	aa_label_match(profile, label, state, false, request, perms);
+}
+
+
+/* currently unused */
+int aa_profile_label_perm(struct aa_profile *profile, struct aa_profile *target,
+			  u32 request, int type, u32 *deny,
+			  struct common_audit_data *sa)
+{
+	struct aa_perms perms;
+
+	aad(sa)->label = &profile->label;
+	aad(sa)->peer = &target->label;
+	aad(sa)->request = request;
+
+	aa_profile_match_label(profile, &target->label, type, request, &perms);
+	aa_apply_modes_to_perms(profile, &perms);
+	*deny |= request & perms.deny;
+	return aa_check_perms(profile, &perms, request, sa, aa_audit_perms_cb);
+}
+
+/**
+ * aa_check_perms - do audit mode selection based on perms set
+ * @profile: profile being checked
+ * @perms: perms computed for the request
+ * @request: requested perms
+ * @deny: Returns: explicit deny set
+ * @sa: 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
+ *
+ * Note: profile audit modes need to be set before calling by setting the
+ *       perm masks appropriately.
+ *
+ *       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.
+ */
+int aa_check_perms(struct aa_profile *profile, struct aa_perms *perms,
+		   u32 request, struct common_audit_data *sa,
+		   void (*cb)(struct audit_buffer *, void *))
+{
+	int type, error;
+	u32 denied = request & (~perms->allow | perms->deny);
+
+	if (likely(!denied)) {
+		/* mask off perms that are not being force audited */
+		request &= perms->audit;
+		if (!request || !sa)
+			return 0;
+
+		type = AUDIT_APPARMOR_AUDIT;
+		error = 0;
+	} else {
+		error = -EACCES;
+
+		if (denied & perms->kill)
+			type = AUDIT_APPARMOR_KILL;
+		else if (denied == (denied & perms->complain))
+			type = AUDIT_APPARMOR_ALLOWED;
+		else
+			type = AUDIT_APPARMOR_DENIED;
+
+		if (denied == (denied & perms->hide))
+			error = -ENOENT;
+
+		denied &= ~perms->quiet;
+		if (!sa || !denied)
+			return error;
+	}
+
+	if (sa) {
+		aad(sa)->label = &profile->label;
+		aad(sa)->request = request;
+		aad(sa)->denied = denied;
+		aad(sa)->error = error;
+		aa_audit_msg(type, sa, cb);
+	}
+
+	if (type == AUDIT_APPARMOR_ALLOWED)
+		error = 0;
+
+	return error;
+}
+
+
+/**
+ * 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
+ *
+ * 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 aa_policy_destroy(struct aa_policy *policy)
+{
+	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);
+}