linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Creating audit events from TTY input.

 *

 * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.

 *

 * Authors: Miloslav Trmac <mitr@redhat.com>

 */

​

#include <linux/audit.h>

#include <linux/slab.h>

#include <linux/tty.h>

​

struct tty_audit_buf {

    struct mutex mutex; /* Protects all data below */

    dev_t dev;      /* The TTY which the data is from */

    unsigned icanon:1;

    size_t valid;

    unsigned char *data;    /* Allocated size N_TTY_BUF_SIZE */

};

​

static struct tty_audit_buf *tty_audit_buf_ref(void)

{

    struct tty_audit_buf *buf;

​

    buf = current->signal->tty_audit_buf;

    WARN_ON(buf == ERR_PTR(-ESRCH));

    return buf;

}

​

static struct tty_audit_buf *tty_audit_buf_alloc(void)

{

    struct tty_audit_buf *buf;

​

    buf = kmalloc(sizeof(*buf), GFP_KERNEL);

    if (!buf)

        goto err;

    buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);

    if (!buf->data)

        goto err_buf;

    mutex_init(&buf->mutex);

    buf->dev = MKDEV(0, 0);

    buf->icanon = 0;

    buf->valid = 0;

    return buf;

​

err_buf:

    kfree(buf);

err:

    return NULL;

}

​

static void tty_audit_buf_free(struct tty_audit_buf *buf)

{

    WARN_ON(buf->valid != 0);

    kfree(buf->data);

    kfree(buf);

}

​

static void tty_audit_log(const char *description, dev_t dev,

              unsigned char *data, size_t size)

{

    struct audit_buffer *ab;

    pid_t pid = task_pid_nr(current);

    uid_t uid = from_kuid(&init_user_ns, task_uid(current));

    uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current));

    unsigned int sessionid = audit_get_sessionid(current);

​

    ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_TTY);

    if (ab) {

        char name[sizeof(current->comm)];

​

        audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u major=%d"

                 " minor=%d comm=", description, pid, uid,

                 loginuid, sessionid, MAJOR(dev), MINOR(dev));

        get_task_comm(name, current);

        audit_log_untrustedstring(ab, name);

        audit_log_format(ab, " data=");

        audit_log_n_hex(ab, data, size);

        audit_log_end(ab);

    }

}

​

/**

 *  tty_audit_buf_push  -   Push buffered data out

 *

 *  Generate an audit message from the contents of @buf, which is owned by

 *  the current task.  @buf->mutex must be locked.

 */

static void tty_audit_buf_push(struct tty_audit_buf *buf)

{

    if (buf->valid == 0)