mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Richard Guy Briggs](/assets/img/avatar_default.png)
AUDIT_TTY records were logged as seperate events from their syscall records. Join them so they are logged as the single event that they are. Please see the github issue https://github.com/linux-audit/audit-kernel/issues/106 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
247 lines
5.6 KiB
C
247 lines
5.6 KiB
C
// 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)
|
|
return;
|
|
if (audit_enabled == AUDIT_OFF) {
|
|
buf->valid = 0;
|
|
return;
|
|
}
|
|
tty_audit_log("tty", buf->dev, buf->data, buf->valid);
|
|
buf->valid = 0;
|
|
}
|
|
|
|
/**
|
|
* tty_audit_exit - Handle a task exit
|
|
*
|
|
* Make sure all buffered data is written out and deallocate the buffer.
|
|
* Only needs to be called if current->signal->tty_audit_buf != %NULL.
|
|
*
|
|
* The process is single-threaded at this point; no other threads share
|
|
* current->signal.
|
|
*/
|
|
void tty_audit_exit(void)
|
|
{
|
|
struct tty_audit_buf *buf;
|
|
|
|
buf = xchg(¤t->signal->tty_audit_buf, ERR_PTR(-ESRCH));
|
|
if (!buf)
|
|
return;
|
|
|
|
tty_audit_buf_push(buf);
|
|
tty_audit_buf_free(buf);
|
|
}
|
|
|
|
/**
|
|
* tty_audit_fork - Copy TTY audit state for a new task
|
|
*
|
|
* Set up TTY audit state in @sig from current. @sig needs no locking.
|
|
*/
|
|
void tty_audit_fork(struct signal_struct *sig)
|
|
{
|
|
sig->audit_tty = current->signal->audit_tty;
|
|
}
|
|
|
|
/**
|
|
* tty_audit_tiocsti - Log TIOCSTI
|
|
*/
|
|
void tty_audit_tiocsti(struct tty_struct *tty, char ch)
|
|
{
|
|
dev_t dev;
|
|
|
|
dev = MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
|
|
if (tty_audit_push())
|
|
return;
|
|
|
|
if (audit_enabled)
|
|
tty_audit_log("ioctl=TIOCSTI", dev, &ch, 1);
|
|
}
|
|
|
|
/**
|
|
* tty_audit_push - Flush current's pending audit data
|
|
*
|
|
* Returns 0 if success, -EPERM if tty audit is disabled
|
|
*/
|
|
int tty_audit_push(void)
|
|
{
|
|
struct tty_audit_buf *buf;
|
|
|
|
if (~current->signal->audit_tty & AUDIT_TTY_ENABLE)
|
|
return -EPERM;
|
|
|
|
buf = tty_audit_buf_ref();
|
|
if (!IS_ERR_OR_NULL(buf)) {
|
|
mutex_lock(&buf->mutex);
|
|
tty_audit_buf_push(buf);
|
|
mutex_unlock(&buf->mutex);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tty_audit_buf_get - Get an audit buffer.
|
|
*
|
|
* Get an audit buffer, allocate it if necessary. Return %NULL
|
|
* if out of memory or ERR_PTR(-ESRCH) if tty_audit_exit() has already
|
|
* occurred. Otherwise, return a new reference to the buffer.
|
|
*/
|
|
static struct tty_audit_buf *tty_audit_buf_get(void)
|
|
{
|
|
struct tty_audit_buf *buf;
|
|
|
|
buf = tty_audit_buf_ref();
|
|
if (buf)
|
|
return buf;
|
|
|
|
buf = tty_audit_buf_alloc();
|
|
if (buf == NULL) {
|
|
audit_log_lost("out of memory in TTY auditing");
|
|
return NULL;
|
|
}
|
|
|
|
/* Race to use this buffer, free it if another wins */
|
|
if (cmpxchg(¤t->signal->tty_audit_buf, NULL, buf) != NULL)
|
|
tty_audit_buf_free(buf);
|
|
return tty_audit_buf_ref();
|
|
}
|
|
|
|
/**
|
|
* tty_audit_add_data - Add data for TTY auditing.
|
|
*
|
|
* Audit @data of @size from @tty, if necessary.
|
|
*/
|
|
void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size)
|
|
{
|
|
struct tty_audit_buf *buf;
|
|
unsigned int icanon = !!L_ICANON(tty);
|
|
unsigned int audit_tty;
|
|
dev_t dev;
|
|
|
|
audit_tty = READ_ONCE(current->signal->audit_tty);
|
|
if (~audit_tty & AUDIT_TTY_ENABLE)
|
|
return;
|
|
|
|
if (unlikely(size == 0))
|
|
return;
|
|
|
|
if (tty->driver->type == TTY_DRIVER_TYPE_PTY
|
|
&& tty->driver->subtype == PTY_TYPE_MASTER)
|
|
return;
|
|
|
|
if ((~audit_tty & AUDIT_TTY_LOG_PASSWD) && icanon && !L_ECHO(tty))
|
|
return;
|
|
|
|
buf = tty_audit_buf_get();
|
|
if (IS_ERR_OR_NULL(buf))
|
|
return;
|
|
|
|
mutex_lock(&buf->mutex);
|
|
dev = MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
|
|
if (buf->dev != dev || buf->icanon != icanon) {
|
|
tty_audit_buf_push(buf);
|
|
buf->dev = dev;
|
|
buf->icanon = icanon;
|
|
}
|
|
do {
|
|
size_t run;
|
|
|
|
run = N_TTY_BUF_SIZE - buf->valid;
|
|
if (run > size)
|
|
run = size;
|
|
memcpy(buf->data + buf->valid, data, run);
|
|
buf->valid += run;
|
|
data += run;
|
|
size -= run;
|
|
if (buf->valid == N_TTY_BUF_SIZE)
|
|
tty_audit_buf_push(buf);
|
|
} while (size != 0);
|
|
mutex_unlock(&buf->mutex);
|
|
}
|