diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2014-12-30 10:39:25 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-09 13:46:02 -0800 |
| commit | 86f2c00f1d8e344965cf8df8572ed5f682956995 (patch) | |
| tree | 3afe1620aba69b36ab45ff9fe26e368e452f25eb /drivers/tty/tty_io.c | |
| parent | 72a3c0e4e6624a77ee6eee0903f209185fe20647 (diff) | |
| download | linux-86f2c00f1d8e344965cf8df8572ed5f682956995.tar.bz2 | |
tty: Prevent hw state corruption in exclusive mode reopen
Exclusive mode ttys (TTY_EXCLUSIVE) do not allow further reopens;
fail the condition before associating the file pointer and calling
the driver open() method.
Prevents DTR programming when the tty is already in exclusive mode.
Reported-by: Shreyas Bethur <shreyas.bethur@ni.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Shreyas Bethur <shreyas.bethur@ni.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_io.c')
| -rw-r--r-- | drivers/tty/tty_io.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 4f35b43e2475..51f066aa375e 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1464,6 +1464,9 @@ static int tty_reopen(struct tty_struct *tty) driver->subtype == PTY_TYPE_MASTER) return -EIO; + if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) + return -EBUSY; + tty->count++; WARN_ON(!tty->ldisc); @@ -2106,10 +2109,6 @@ retry_open: retval = -ENODEV; filp->f_flags = saved_flags; - if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && - !capable(CAP_SYS_ADMIN)) - retval = -EBUSY; - if (retval) { #ifdef TTY_DEBUG_HANGUP printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, |