[PATCH 03/15] tty: audit: Remove icanon mode from call chain

[Richard Guy Briggs]

On 15/11/10, Peter Hurley wrote:
> The tty termios bits cannot change while n_tty_read() is in the
> i/o loop; the termios_rwsem ensures mutual exclusion with termios
> changes in n_tty_set_termios(). Check L_ICANON() directly and
> eliminate icanon parameter.
> 
> NB: tty_audit_add_data() => tty_audit_buf_get() => tty_audit_buf_alloc()
> is a single path; ie., tty_audit_buf_get() and tty_audit_buf_alloc()
> have no other callers.

Which tree is this based on?  I don't see where the first chunk applies.

> Signed-off-by: Peter Hurley <peter at hurleysoftware.com>
> ---
>  drivers/tty/n_tty.c     |  6 +++---
>  drivers/tty/tty_audit.c | 22 +++++++++-------------
>  include/linux/tty.h     |  4 ++--
>  3 files changed, 14 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
> index b09c0c1..a3ad312 100644
> --- a/drivers/tty/n_tty.c
> +++ b/drivers/tty/n_tty.c
> @@ -163,7 +163,7 @@ static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
>  	int uncopied;
>  
>  	if (n > size) {
> -		tty_audit_add_data(tty, from, size, ldata->icanon);
> +		tty_audit_add_data(tty, from, size);
>  		uncopied = copy_to_user(to, from, size);
>  		if (uncopied)
>  			return uncopied;
> @@ -172,7 +172,7 @@ static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
>  		from = ldata->read_buf;
>  	}
>  
> -	tty_audit_add_data(tty, from, n, ldata->icanon);
> +	tty_audit_add_data(tty, from, n);
>  	return copy_to_user(to, from, n);
>  }
>  
> @@ -2008,7 +2008,7 @@ static int copy_from_read_buf(struct tty_struct *tty,
>  		retval = copy_to_user(*b, from, n);
>  		n -= retval;
>  		is_eof = n == 1 && *from == EOF_CHAR(tty);
> -		tty_audit_add_data(tty, from, n, ldata->icanon);
> +		tty_audit_add_data(tty, from, n);
>  		smp_store_release(&ldata->read_tail, ldata->read_tail + n);
>  		/* Turn single EOF into zero-length read */
>  		if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
> diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
> index ead924e..d2a004a 100644
> --- a/drivers/tty/tty_audit.c
> +++ b/drivers/tty/tty_audit.c
> @@ -22,8 +22,7 @@ struct tty_audit_buf {
>  	unsigned char *data;	/* Allocated size N_TTY_BUF_SIZE */
>  };
>  
> -static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
> -						 unsigned icanon)
> +static struct tty_audit_buf *tty_audit_buf_alloc(struct tty_struct *tty)
>  {
>  	struct tty_audit_buf *buf;
>  
> @@ -35,9 +34,9 @@ static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
>  		goto err_buf;
>  	atomic_set(&buf->count, 1);
>  	mutex_init(&buf->mutex);
> -	buf->major = major;
> -	buf->minor = minor;
> -	buf->icanon = icanon;
> +	buf->major = tty->driver->major;
> +	buf->minor = tty->driver->minor_start + tty->index;
> +	buf->icanon = !!L_ICANON(tty);
>  	buf->valid = 0;
>  	return buf;
>  
> @@ -216,8 +215,7 @@ int tty_audit_push_current(void)
>   *	if TTY auditing is disabled or out of memory.  Otherwise, return a new
>   *	reference to the buffer.
>   */
> -static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
> -		unsigned icanon)
> +static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty)
>  {
>  	struct tty_audit_buf *buf, *buf2;
>  	unsigned long flags;
> @@ -234,9 +232,7 @@ static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
>  	}
>  	spin_unlock_irqrestore(&current->sighand->siglock, flags);
>  
> -	buf2 = tty_audit_buf_alloc(tty->driver->major,
> -				   tty->driver->minor_start + tty->index,
> -				   icanon);
> +	buf2 = tty_audit_buf_alloc(tty);
>  	if (buf2 == NULL) {
>  		audit_log_lost("out of memory in TTY auditing");
>  		return NULL;
> @@ -265,13 +261,13 @@ static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
>   *
>   *	Audit @data of @size from @tty, if necessary.
>   */
> -void tty_audit_add_data(struct tty_struct *tty, const void *data,
> -			size_t size, unsigned icanon)
> +void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size)
>  {
>  	struct tty_audit_buf *buf;
>  	int major, minor;
>  	int audit_log_tty_passwd;
>  	unsigned long flags;
> +	unsigned int icanon = !!L_ICANON(tty);
>  
>  	if (unlikely(size == 0))
>  		return;
> @@ -286,7 +282,7 @@ void tty_audit_add_data(struct tty_struct *tty, const void *data,
>  	if (!audit_log_tty_passwd && icanon && !L_ECHO(tty))
>  		return;
>  
> -	buf = tty_audit_buf_get(tty, icanon);
> +	buf = tty_audit_buf_get(tty);
>  	if (!buf)
>  		return;
>  
> diff --git a/include/linux/tty.h b/include/linux/tty.h
> index 70f3a9c1..f8a20a8 100644
> --- a/include/linux/tty.h
> +++ b/include/linux/tty.h
> @@ -603,7 +603,7 @@ extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
>  /* tty_audit.c */
>  #ifdef CONFIG_AUDIT
>  extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
> -			       size_t size, unsigned icanon);
> +			       size_t size);
>  extern void tty_audit_exit(void);
>  extern void tty_audit_fork(struct signal_struct *sig);
>  extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
> @@ -611,7 +611,7 @@ extern void tty_audit_push(struct tty_struct *tty);
>  extern int tty_audit_push_current(void);
>  #else
>  static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
> -				      size_t size, unsigned icanon)
> +				      size_t size)
>  {
>  }
>  static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
> -- 
> 2.6.3
> 
> --
> Linux-audit mailing list
> Linux-audit at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-audit

- RGB

--
Richard Guy Briggs <rbriggs at redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545