Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2025-01-10 07:00:48 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

serial: fix TIOCSRS485 locking

Browse Source 
The RS485 multipoint addressing support for some reason added a new
ADDRB termios cflag which is (only!) updated from one of the RS485
ioctls.

Make sure to take the termios rw semaphore for the right ioctl (i.e.
set, not get).

Fixes: ae50bb275283 ("serial: take termios_rwsem for ->rs485_config() & pass termios as param")
Cc: stable@vger.kernel.org	# 6.0
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20230412124811.11217-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2023-04-12 14:48:11 +02:00 committed by Greg Kroah-Hartman
parent c6c01763f2
commit 9e4f2a8004
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/tty/serial/serial_core.c
View File

@ -1549,7 +1549,7 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
goto out;
/* rs485_config requires more locking than others */
if (cmd == TIOCGRS485)
if (cmd == TIOCSRS485)
down_write(&tty->termios_rwsem);
mutex_lock(&port->mutex);
@ -1592,7 +1592,7 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
}
out_up:
mutex_unlock(&port->mutex);
if (cmd == TIOCGRS485)
if (cmd == TIOCSRS485)
up_write(&tty->termios_rwsem);
out:
return ret;