Johan Hovold 211cde4f58 serial: 8250: fix racy uartclk update ...

Commit 868f3ee6e4 ("serial: 8250: Add 8250 port clock update method")
added a hack to support SoCs where the UART reference clock can
change behind the back of the driver but failed to add the proper
locking.

First, make sure to take a reference to the tty struct to avoid
dereferencing a NULL pointer if the clock change races with a hangup.

Second, the termios semaphore must be held during the update to prevent
a racing termios change.

Fixes: 868f3ee6e4 ("serial: 8250: Add 8250 port clock update method")
Fixes: c8dff3aa82 ("serial: 8250: Skip uninitialized TTY port baud rate update")
Cc: stable@vger.kernel.org      # 5.9
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211015111422.1027-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2021-10-21 10:37:10 +02:00

..

hvc

tty: hvc: pass DMA capable memory to put_chars()

2021-10-21 10:34:33 +02:00

ipwireless

tty: drop put_tty_driver

2021-07-27 12:17:21 +02:00

serdev

Merge tag 'tty-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2021-09-01 09:51:16 -07:00

serial

serial: 8250: fix racy uartclk update

2021-10-21 10:37:10 +02:00

vt

Merge tag 'tty-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2021-09-01 09:51:16 -07:00

amiserial.c

tty: drop put_tty_driver

2021-07-27 12:17:21 +02:00

ehv_bytechan.c

tty: drop put_tty_driver

2021-07-27 12:17:21 +02:00

goldfish.c

tty: drop put_tty_driver

2021-07-27 12:17:21 +02:00

Kconfig

Merge tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

2021-07-09 10:19:13 -07:00

Makefile

tty: remove broken r3964 line discipline

2021-05-13 16:57:15 +02:00

mips_ejtag_fdc.c

tty: drop put_tty_driver

2021-07-27 12:17:21 +02:00

moxa.c

tty: moxa: merge moxa.h into moxa.c

2021-09-14 11:17:27 +02:00

mxser.c

mxser: store FCR state in mxser_port::FCR

2021-10-05 14:08:09 +02:00

n_gsm.c

tty: n_gsm: Don't ignore write return value in gsmld_output()

2021-10-05 14:05:59 +02:00

n_hdlc.c

tty: remove file from n_tty_ioctl_helper

2021-09-22 16:59:13 +02:00

n_null.c

tty: make tty_ldisc_ops a param in tty_unregister_ldisc

2021-05-13 16:57:16 +02:00

n_tty.c

tty: remove file from n_tty_ioctl_helper

2021-09-22 16:59:13 +02:00

nozomi.c

tty: drop put_tty_driver

2021-07-27 12:17:21 +02:00

pty.c

tty: pty: correct function name pty_resize()

2021-05-20 16:33:06 +02:00

synclink_gt.c

tty: synclink_gt: rename a conflicting function name

2021-09-14 10:51:37 +02:00

sysrq.c

tty/sysrq: More intuitive Shift handling

2021-10-10 15:19:43 +02:00

tty_audit.c

tty: audit: move some local functions out of tty.h

2021-04-15 10:24:58 +02:00

tty_baudrate.c

tty: baudrate: Explicit usage of B0 for encoding input baudrate

2021-10-05 15:00:56 +02:00

tty_buffer.c

tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc

2021-10-18 16:53:18 +02:00

tty_io.c

tty: Fix data race between tiocsti() and flush_to_ldisc()

2021-08-26 14:51:38 +02:00

tty_ioctl.c

tty: remove file from n_tty_ioctl_helper

2021-09-22 16:59:13 +02:00

tty_jobctrl.c

tty: tty_jobctrl: Fix 2 incorrectly documented functions

2021-05-20 17:06:15 +02:00

tty_ldisc.c

tty: unexport tty_ldisc_release

2021-09-22 16:59:13 +02:00

tty_ldsem.c

…

tty_mutex.c

tty: move some internal tty lock enums and functions out of tty.h

2021-04-15 10:26:58 +02:00

tty_port.c

tty: tty_port: Fix coding style issues of block comments

2021-05-13 18:29:13 +02:00

tty.h

tty: clean include/linux/tty.h up

2021-04-15 10:32:17 +02:00

ttynull.c

tty: drop put_tty_driver

2021-07-27 12:17:21 +02:00

vcc.c

tty: drop put_tty_driver

2021-07-27 12:17:21 +02:00