auditsc.c

linux 2.6.19 kernel source code before patching

	rcu_read_lock();
	if (!list_empty(list)) {
		int word = AUDIT_WORD(ctx->major);
		int bit  = AUDIT_BIT(ctx->major);

		list_for_each_entry_rcu(e, list, list) {
			if ((e->rule.mask[word] & bit) == bit &&
			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
					       &state)) {
				rcu_read_unlock();
				return state;
			}
		}
	}
	rcu_read_unlock();
	return AUDIT_BUILD_CONTEXT;
}

/* At syscall exit time, this filter is called if any audit_names[] have been
 * collected during syscall processing.  We only check rules in sublists at hash
 * buckets applicable to the inode numbers in audit_names[].
 * Regarding audit_state, same rules apply as for audit_filter_syscall().
 */
enum audit_state audit_filter_inodes(struct task_struct *tsk,
				     struct audit_context *ctx)
{
	int i;
	struct audit_entry *e;
	enum audit_state state;

	if (audit_pid && tsk->tgid == audit_pid)
		return AUDIT_DISABLED;

	rcu_read_lock();
	for (i = 0; i < ctx->name_count; i++) {
		int word = AUDIT_WORD(ctx->major);
		int bit  = AUDIT_BIT(ctx->major);
		struct audit_names *n = &ctx->names[i];
		int h = audit_hash_ino((u32)n->ino);
		struct list_head *list = &audit_inode_hash[h];

		if (list_empty(list))
			continue;

		list_for_each_entry_rcu(e, list, list) {
			if ((e->rule.mask[word] & bit) == bit &&
			    audit_filter_rules(tsk, &e->rule, ctx, n, &state)) {
				rcu_read_unlock();
				return state;
			}
		}
	}
	rcu_read_unlock();
	return AUDIT_BUILD_CONTEXT;
}

void audit_set_auditable(struct audit_context *ctx)
{
	ctx->auditable = 1;
}

static inline struct audit_context *audit_get_context(struct task_struct *tsk,
						      int return_valid,
						      int return_code)
{
	struct audit_context *context = tsk->audit_context;

	if (likely(!context))
		return NULL;
	context->return_valid = return_valid;
	context->return_code  = return_code;

	if (context->in_syscall && !context->dummy && !context->auditable) {
		enum audit_state state;

		state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
		if (state == AUDIT_RECORD_CONTEXT) {
			context->auditable = 1;
			goto get_context;
		}

		state = audit_filter_inodes(tsk, context);
		if (state == AUDIT_RECORD_CONTEXT)
			context->auditable = 1;

	}

get_context:

	tsk->audit_context = NULL;
	return context;
}

static inline void audit_free_names(struct audit_context *context)
{
	int i;

#if AUDIT_DEBUG == 2
	if (context->auditable
	    ||context->put_count + context->ino_count != context->name_count) {
		printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d"
		       " name_count=%d put_count=%d"
		       " ino_count=%d [NOT freeing]\n",
		       __FILE__, __LINE__,
		       context->serial, context->major, context->in_syscall,
		       context->name_count, context->put_count,
		       context->ino_count);
		for (i = 0; i < context->name_count; i++) {
			printk(KERN_ERR "names[%d] = %p = %s\n", i,
			       context->names[i].name,
			       context->names[i].name ?: "(null)");
		}
		dump_stack();
		return;
	}
#endif
#if AUDIT_DEBUG
	context->put_count  = 0;
	context->ino_count  = 0;
#endif

	for (i = 0; i < context->name_count; i++) {
		if (context->names[i].name && context->names[i].name_put)
			__putname(context->names[i].name);
	}
	context->name_count = 0;
	if (context->pwd)
		dput(context->pwd);
	if (context->pwdmnt)
		mntput(context->pwdmnt);
	context->pwd = NULL;
	context->pwdmnt = NULL;
}

static inline void audit_free_aux(struct audit_context *context)
{
	struct audit_aux_data *aux;

	while ((aux = context->aux)) {
		if (aux->type == AUDIT_AVC_PATH) {
			struct audit_aux_data_path *axi = (void *)aux;
			dput(axi->dentry);
			mntput(axi->mnt);
		}

		context->aux = aux->next;
		kfree(aux);
	}
	while ((aux = context->aux_pids)) {
		context->aux_pids = aux->next;
		kfree(aux);
	}
}

static inline void audit_zero_context(struct audit_context *context,
				      enum audit_state state)
{
	uid_t loginuid = context->loginuid;

	memset(context, 0, sizeof(*context));
	context->state      = state;
	context->loginuid   = loginuid;
}

static inline struct audit_context *audit_alloc_context(enum audit_state state)
{
	struct audit_context *context;

	if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
		return NULL;
	audit_zero_context(context, state);
	return context;
}

/**
 * audit_alloc - allocate an audit context block for a task
 * @tsk: task
 *
 * Filter on the task information and allocate a per-task audit context
 * if necessary.  Doing so turns on system call auditing for the
 * specified task.  This is called from copy_process, so no lock is
 * needed.
 */
int audit_alloc(struct task_struct *tsk)
{
	struct audit_context *context;
	enum audit_state     state;

	if (likely(!audit_enabled))
		return 0; /* Return if not auditing. */

	state = audit_filter_task(tsk);
	if (likely(state == AUDIT_DISABLED))
		return 0;

	if (!(context = audit_alloc_context(state))) {
		audit_log_lost("out of memory in audit_alloc");
		return -ENOMEM;
	}

				/* Preserve login uid */
	context->loginuid = -1;
	if (current->audit_context)
		context->loginuid = current->audit_context->loginuid;

	tsk->audit_context  = context;
	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
	return 0;
}

static inline void audit_free_context(struct audit_context *context)
{
	struct audit_context *previous;
	int		     count = 0;

	do {
		previous = context->previous;
		if (previous || (count &&  count < 10)) {
			++count;
			printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
			       " freeing multiple contexts (%d)\n",
			       context->serial, context->major,
			       context->name_count, count);
		}
		audit_free_names(context);
		audit_free_aux(context);
		kfree(context->filterkey);
		kfree(context);
		context  = previous;
	} while (context);
	if (count >= 10)
		printk(KERN_ERR "audit: freed %d contexts\n", count);
}

void audit_log_task_context(struct audit_buffer *ab)
{
	char *ctx = NULL;
	unsigned len;
	int error;
	u32 sid;

	selinux_get_task_sid(current, &sid);
	if (!sid)
		return;

	error = selinux_sid_to_string(sid, &ctx, &len);
	if (error) {
		if (error != -EINVAL)
			goto error_path;
		return;
	}

	audit_log_format(ab, " subj=%s", ctx);
	kfree(ctx);
	return;

error_path:
	audit_panic("error in audit_log_task_context");
	return;
}

EXPORT_SYMBOL(audit_log_task_context);

static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
{
	char name[sizeof(tsk->comm)];
	struct mm_struct *mm = tsk->mm;
	struct vm_area_struct *vma;

	/* tsk == current */

	get_task_comm(name, tsk);
	audit_log_format(ab, " comm=");
	audit_log_untrustedstring(ab, name);

	if (mm) {
		down_read(&mm->mmap_sem);
		vma = mm->mmap;
		while (vma) {
			if ((vma->vm_flags & VM_EXECUTABLE) &&
			    vma->vm_file) {
				audit_log_d_path(ab, "exe=",
						 vma->vm_file->f_path.dentry,
						 vma->vm_file->f_path.mnt);
				break;
			}
			vma = vma->vm_next;
		}
		up_read(&mm->mmap_sem);
	}
	audit_log_task_context(ab);
}

static int audit_log_pid_context(struct audit_context *context, pid_t pid,
				 u32 sid)
{
	struct audit_buffer *ab;
	char *s = NULL;
	u32 len;
	int rc = 0;

	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
	if (!ab)
		return 1;

	if (selinux_sid_to_string(sid, &s, &len)) {
		audit_log_format(ab, "opid=%d obj=(none)", pid);
		rc = 1;
	} else
		audit_log_format(ab, "opid=%d  obj=%s", pid, s);
	audit_log_end(ab);
	kfree(s);

	return rc;
}

static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
{
	int i, call_panic = 0;
	struct audit_buffer *ab;
	struct audit_aux_data *aux;
	const char *tty;

	/* tsk == current */
	context->pid = tsk->pid;
	if (!context->ppid)
		context->ppid = sys_getppid();
	context->uid = tsk->uid;
	context->gid = tsk->gid;
	context->euid = tsk->euid;
	context->suid = tsk->suid;
	context->fsuid = tsk->fsuid;
	context->egid = tsk->egid;
	context->sgid = tsk->sgid;
	context->fsgid = tsk->fsgid;
	context->personality = tsk->personality;

	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
	if (!ab)
		return;		/* audit_panic has been called */
	audit_log_format(ab, "arch=%x syscall=%d",
			 context->arch, context->major);
	if (context->personality != PER_LINUX)
		audit_log_format(ab, " per=%lx", context->personality);
	if (context->return_valid)
		audit_log_format(ab, " success=%s exit=%ld", 
				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
				 context->return_code);

	mutex_lock(&tty_mutex);
	read_lock(&tasklist_lock);
	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
		tty = tsk->signal->tty->name;
	else
		tty = "(none)";
	read_unlock(&tasklist_lock);
	audit_log_format(ab,
		  " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
		  " ppid=%d pid=%d auid=%u uid=%u gid=%u"
		  " euid=%u suid=%u fsuid=%u"
		  " egid=%u sgid=%u fsgid=%u tty=%s",
		  context->argv[0],
		  context->argv[1],
		  context->argv[2],
		  context->argv[3],
		  context->name_count,
		  context->ppid,
		  context->pid,
		  context->loginuid,
		  context->uid,
		  context->gid,
		  context->euid, context->suid, context->fsuid,
		  context->egid, context->sgid, context->fsgid, tty);

	mutex_unlock(&tty_mutex);

	audit_log_task_info(ab, tsk);
	if (context->filterkey) {
		audit_log_format(ab, " key=");
		audit_log_untrustedstring(ab, context->filterkey);
	} else
		audit_log_format(ab, " key=(null)");
	audit_log_end(ab);

	for (aux = context->aux; aux; aux = aux->next) {

		ab = audit_log_start(context, GFP_KERNEL, aux->type);
		if (!ab)
			continue; /* audit_panic has been called */

		switch (aux->type) {
		case AUDIT_MQ_OPEN: {
			struct audit_aux_data_mq_open *axi = (void *)aux;
			audit_log_format(ab,
				"oflag=0x%x mode=%#o mq_flags=0x%lx mq_maxmsg=%ld "
				"mq_msgsize=%ld mq_curmsgs=%ld",
				axi->oflag, axi->mode, axi->attr.mq_flags,
				axi->attr.mq_maxmsg, axi->attr.mq_msgsize,
				axi->attr.mq_curmsgs);
			break; }

		case AUDIT_MQ_SENDRECV: {
			struct audit_aux_data_mq_sendrecv *axi = (void *)aux;
			audit_log_format(ab,
				"mqdes=%d msg_len=%zd msg_prio=%u "
				"abs_timeout_sec=%ld abs_timeout_nsec=%ld",
				axi->mqdes, axi->msg_len, axi->msg_prio,
				axi->abs_timeout.tv_sec, axi->abs_timeout.tv_nsec);
			break; }

		case AUDIT_MQ_NOTIFY: {
			struct audit_aux_data_mq_notify *axi = (void *)aux;
			audit_log_format(ab,
				"mqdes=%d sigev_signo=%d",
				axi->mqdes,
				axi->notification.sigev_signo);
			break; }

		case AUDIT_MQ_GETSETATTR: {
			struct audit_aux_data_mq_getsetattr *axi = (void *)aux;
			audit_log_format(ab,
				"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
				"mq_curmsgs=%ld ",
				axi->mqdes,
				axi->mqstat.mq_flags, axi->mqstat.mq_maxmsg,
				axi->mqstat.mq_msgsize, axi->mqstat.mq_curmsgs);
			break; }

		case AUDIT_IPC: {
			struct audit_aux_data_ipcctl *axi = (void *)aux;
			audit_log_format(ab, 
				 "ouid=%u ogid=%u mode=%x",
				 axi->uid, axi->gid, axi->mode);
			if (axi->osid != 0) {
				char *ctx = NULL;
				u32 len;
				if (selinux_sid_to_string(
						axi->osid, &ctx, &len)) {
					audit_log_format(ab, " osid=%u",
							axi->osid);
					call_panic = 1;
				} else
					audit_log_format(ab, " obj=%s", ctx);
				kfree(ctx);
			}
			break; }

		case AUDIT_IPC_SET_PERM: {
			struct audit_aux_data_ipcctl *axi = (void *)aux;
			audit_log_format(ab,
				"qbytes=%lx ouid=%u ogid=%u mode=%x",
				axi->qbytes, axi->uid, axi->gid, axi->mode);
			break; }

		case AUDIT_EXECVE: {
			struct audit_aux_data_execve *axi = (void *)aux;
			int i;
			const char *p;
			for (i = 0, p = axi->mem; i < axi->argc; i++) {
				audit_log_format(ab, "a%d=", i);
				p = audit_log_untrustedstring(ab, p);
				audit_log_format(ab, "\n");
			}
			break; }

		case AUDIT_SOCKETCALL: {
			int i;
			struct audit_aux_data_socketcall *axs = (void *)aux;
			audit_log_format(ab, "nargs=%d", axs->nargs);
			for (i=0; i<axs->nargs; i++)
				audit_log_format(ab, " a%d=%lx", i, axs->args[i]);
			break; }

		case AUDIT_SOCKADDR: {
			struct audit_aux_data_sockaddr *axs = (void *)aux;

			audit_log_format(ab, "saddr=");
			audit_log_hex(ab, axs->a, axs->len);
			break; }

		case AUDIT_AVC_PATH: {
			struct audit_aux_data_path *axi = (void *)aux;
			audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
			break; }

		case AUDIT_FD_PAIR: {
			struct audit_aux_data_fd_pair *axs = (void *)aux;
			audit_log_format(ab, "fd0=%d fd1=%d", axs->fd[0], axs->fd[1]);
			break; }

		}
		audit_log_end(ab);
	}

	for (aux = context->aux_pids; aux; aux = aux->next) {
		struct audit_aux_data_pids *axs = (void *)aux;
		int i;

		for (i = 0; i < axs->pid_count; i++)
			if (audit_log_pid_context(context, axs->target_pid[i],
						  axs->target_sid[i]))
				call_panic = 1;
	}

	if (context->target_pid &&
	    audit_log_pid_context(context, context->target_pid,
				  context->target_sid))
			call_panic = 1;

	if (context->pwd && context->pwdmnt) {
		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
		if (ab) {
			audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt);
			audit_log_end(ab);
		}
	}
	for (i = 0; i < context->name_count; i++) {
		struct audit_names *n = &context->names[i];

		ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);