Commit 309426ae authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman
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tty: audit: Remove icanon mode from call chain 



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.

Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent eab25a5c

drivers/tty/n_tty.c

+3 −3
Original line number Diff line number Diff line
@@ -162,7 +162,7 @@ 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;
@@ -171,7 +171,7 @@ 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);

}
@@ -1978,7 +1978,7 @@ 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 &&

drivers/tty/tty_audit.c

+9 −13
Original line number Diff line number Diff line
@@ -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;

include/linux/tty.h

+2 −2
Original line number Diff line number Diff line
@@ -593,7 +593,7 @@ extern void __init n_tty_init(void); 
/* 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);
@@ -601,7 +601,7 @@ 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)

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