// SPDX-License-Identifier: GPL-2.0-only/* * AppArmor security module * * This file contains AppArmor /proc/<pid>/attr/ interface functions * * Copyright (C) 1998-2008 Novell/SUSE * Copyright 2009-2010 Canonical Ltd. */ #include "include/apparmor.h"#include "include/cred.h"#include "include/policy.h"#include "include/policy_ns.h"#include "include/domain.h"#include "include/procattr.h"  /** * aa_getprocattr - Return the label information for @label * @label: the label to print label info about  (NOT NULL) * @string: Returns - string containing the label info (NOT NULL) * @newline: indicates that a newline should be added * * Requires: label != NULL && string != NULL * * Creates a string containing the label information for @label. * * Returns: size of string placed in @string else error code on failure */int aa_getprocattr(struct aa_label *label, char **string, bool newline){	struct aa_ns *ns = labels_ns(label);	struct aa_ns *current_ns = aa_get_current_ns();	int len; 	if (!aa_ns_visible(current_ns, ns, true)) {		aa_put_ns(current_ns);		return -EACCES;	} 	len = aa_label_snxprint(NULL, 0, current_ns, label,				FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |				FLAG_HIDDEN_UNCONFINED);	AA_BUG(len < 0); 	*string = kmalloc(len + 2, GFP_KERNEL);	if (!*string) {		aa_put_ns(current_ns);		return -ENOMEM;	} 	len = aa_label_snxprint(*string, len + 2, current_ns, label,				FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |				FLAG_HIDDEN_UNCONFINED);	if (len < 0) {		kfree(*string);		*string = NULL;		aa_put_ns(current_ns);		return len;	} 	if (newline)		(*string)[len++] = '\n';	(*string)[len] = 0; 	aa_put_ns(current_ns);	return len;} /** * split_token_from_name - separate a string of form  <token>^<name> * @op: operation being checked * @args: string to parse  (NOT NULL) * @token: stores returned parsed token value  (NOT NULL) * * Returns: start position of name after token else NULL on failure */static char *split_token_from_name(const char *op, char *args, u64 *token){	char *name; 	*token = simple_strtoull(args, &name, 16);	if ((name == args) || *name != '^') {		AA_ERROR("%s: Invalid input '%s'", op, args);		return ERR_PTR(-EINVAL);	} 	name++;			/* skip ^ */	if (!*name)		name = NULL;	return name;} /** * aa_setprocattr_changehat - handle procattr interface to change_hat * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL) * @size: size of the args * @flags: set of flags governing behavior * * Returns: %0 or error code if change_hat fails */int aa_setprocattr_changehat(char *args, size_t size, int flags){	char *hat;	u64 token;	const char *hats[16];		/* current hard limit on # of names */	int count = 0; 	hat = split_token_from_name(OP_CHANGE_HAT, args, &token);	if (IS_ERR(hat))		return PTR_ERR(hat); 	if (!hat && !token) {		AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");		return -EINVAL;	} 	if (hat) {		/* set up hat name vector, args guaranteed null terminated		 * at args[size] by setprocattr.		 *		 * If there are multiple hat names in the buffer each is		 * separated by a \0.  Ie. userspace writes them pre tokenized		 */		char *end = args + size;		for (count = 0; (hat < end) && count < 16; ++count) {			char *next = hat + strlen(hat) + 1;			hats[count] = hat;			AA_DEBUG(DEBUG_DOMAIN,				 "%s: (pid %d) Magic 0x%llx count %d hat '%s'\n"				 , __func__, current->pid, token, count, hat);			hat = next;		}	} else		AA_DEBUG(DEBUG_DOMAIN,			 "%s: (pid %d) Magic 0x%llx count %d Hat '%s'\n",			 __func__, current->pid, token, count, "<NULL>"); 	return aa_change_hat(hats, count, token, flags);}