linux-stable.git/drivers/tty, branch v3.12.64

tty/vt/keyboard: fix OOB access in do_compute_shiftstate()

2016-08-19T07:50:49+00:00

commit 510cccb5b0c8868a2b302a0ab524da7912da648b upstream.

The size of individual keymap in drivers/tty/vt/keyboard.c is NR_KEYS,
which is currently 256, whereas number of keys/buttons in input device (and
therefor in key_down) is much larger - KEY_CNT - 768, and that can cause
out-of-bound access when we do

	sym = U(key_maps[0][k]);

with large 'k'.

To fix it we should not attempt iterating beyond smaller of NR_KEYS and
KEY_CNT.

Also while at it let's switch to for_each_set_bit() instead of open-coding
it.

Reported-by: Sasha Levin 
Reviewed-by: Guenter Roeck 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Jiri Slaby

serial: samsung: Reorder the sequence of clock control when call s3c24xx_serial_set_termios()

2016-06-15T07:32:09+00:00

commit b8995f527aac143e83d3900ff39357651ea4e0f6 upstream.

This patch fixes the broken serial log when changing the clock source
of uart device. Before disabling the original clock source, this patch
enables the new clock source to protect the clock off state for a split second.

Signed-off-by: Chanwoo Choi 
Reviewed-by: Marek Szyprowski 
Signed-off-by: Greg Kroah-Hartman 
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Jiri Slaby

tty: vt, return error when con_startup fails

2016-06-15T07:32:08+00:00

commit 6798df4c5fe0a7e6d2065cf79649a794e5ba7114 upstream.

When csw->con_startup() fails in do_register_con_driver, we return no
error (i.e. 0). This was changed back in 2006 by commit 3e795de763.
Before that we used to return -ENODEV.

So fix the return value to be -ENODEV in that case again.

Fixes: 3e795de763 ("VT binding: Add binding/unbinding support for the VT console")
Signed-off-by: Jiri Slaby 
Reported-by: "Dan Carpenter" 
Signed-off-by: Jiri Slaby

serial: sh-sci: Remove cpufreq notifier to fix crash/deadlock

2016-05-03T05:45:08+00:00

commit ff1cab374ad98f4b9f408525ca9c08992b4ed784 upstream.

The BSP team noticed that there is spin/mutex lock issue on sh-sci when
CPUFREQ is used.  The issue is that the notifier function may call
mutex_lock() while the spinlock is held, which can lead to a BUG().
This may happen if CPUFREQ is changed while another CPU calls
clk_get_rate().

Taking the spinlock was added to the notifier function in commit
e552de2413edad1a ("sh-sci: add platform device private data"), to
protect the list of serial ports against modification during traversal.
At that time the Common Clock Framework didn't exist yet, and
clk_get_rate() just returned clk->rate without taking a mutex.
Note that since commit d535a2305facf9b4 ("serial: sh-sci: Require a
device per port mapping."), there's no longer a list of serial ports to
traverse, and taking the spinlock became superfluous.

To fix the issue, just remove the cpufreq notifier:
  1. The notifier doesn't work correctly: all it does is update stored
     clock rates; it does not update the divider in the hardware.
     The divider will only be updated when calling sci_set_termios().
     I believe this was broken back in 2004, when the old
     drivers/char/sh-sci.c driver (where the notifier did update the
     divider) was replaced by drivers/serial/sh-sci.c (where the
     notifier just updated port->uartclk).
     Cfr. full-history-linux commits 6f8deaef2e9675d9 ("[PATCH] sh: port
     sh-sci driver to the new API") and 3f73fe878dc9210a ("[PATCH]
     Remove old sh-sci driver").
  2. On modern SoCs, the sh-sci parent clock rate is no longer related
     to the CPU clock rate anyway, so using a cpufreq notifier is
     futile.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jiri Slaby

8250: use callbacks to access UART_DLL/UART_DLM

2016-04-11T14:44:13+00:00

commit 0b41ce991052022c030fd868e03877700220b090 upstream.

Some UART HW has a single register combining UART_DLL/UART_DLM
(this was probably forgotten in the change that introduced the
callbacks, commit b32b19b8ffc05cbd3bf91c65e205f6a912ca15d9)

Fixes: b32b19b8ffc0 ("[SERIAL] 8250: set divisor register correctly ...")

Signed-off-by: Sebastian Frias 
Reviewed-by: Peter Hurley 
Signed-off-by: Jiri Slaby

serial: 8250_pci: Correct uartclk for xr17v35x expansion chips

2016-02-24T09:23:18+00:00

commit 899f0c1c7dbcc487fdc8756a49ff70b1d5d75f89 upstream.

The internal clock of the master chip, which is usually 125MHz, is only half
(62.5MHz) for the slave chips. So we have to adjust the uartclk for all the
slave ports. Therefor we add a new function to determine if a slave chip is
present and update pci_xr17v35x_setup accordingly.

Signed-off-by: Soeren Grunewald 
Signed-off-by: Jiri Slaby

pty: make sure super_block is still valid in final /dev/tty close

2016-02-24T09:23:17+00:00

commit 1f55c718c290616889c04946864a13ef30f64929 upstream.

Considering current pty code and multiple devpts instances, it's possible
to umount a devpts file system while a program still has /dev/tty opened
pointing to a previosuly closed pty pair in that instance. In the case all
ptmx and pts/N files are closed, umount can be done. If the program closes
/dev/tty after umount is done, devpts_kill_index will use now an invalid
super_block, which was already destroyed in the umount operation after
running ->kill_sb. This is another "use after free" type of issue, but now
related to the allocated super_block instance.

To avoid the problem (warning at ida_remove and potential crashes) for
this specific case, I added two functions in devpts which grabs additional
references to the super_block, which pty code now uses so it makes sure
the super block structure is still valid until pty shutdown is done.
I also moved the additional inode references to the same functions, which
also covered similar case with inode being freed before /dev/tty final
close/shutdown.

Signed-off-by: Herton R. Krzesinski 
Reviewed-by: Peter Hurley 
Signed-off-by: Jiri Slaby

pty: fix possible use after free of tty->driver_data

2016-02-24T09:23:16+00:00

commit 2831c89f42dcde440cfdccb9fee9f42d54bbc1ef upstream.

This change fixes a bug for a corner case where we have the the last
release from a pty master/slave coming from a previously opened /dev/tty
file. When this happens, the tty->driver_data can be stale, due to all
ptmx or pts/N files having already been closed before (and thus the inode
related to these files, which tty->driver_data points to, being already
freed/destroyed).

The fix here is to keep a reference on the opened master ptmx inode.
We maintain the inode referenced until the final pty_unix98_shutdown,
and only pass this inode to devpts_kill_index.

Signed-off-by: Herton R. Krzesinski 
Reviewed-by: Peter Hurley 
Signed-off-by: Jiri Slaby

tty: remove platform_sysrq_reset_seq

2016-02-24T08:45:14+00:00

commit ffb6e0c9a0572f8e5f8e9337a1b40ac2ec1493a1 upstream.

The platform_sysrq_reset_seq code was intended as a way for an embedded
platform to provide its own sysrq sequence at compile time. After over two
years, nobody has started using it in an upstream kernel, and the platforms
that were interested in it have moved on to devicetree, which can be used
to configure the sequence without requiring kernel changes. The method is
also incompatible with the way that most architectures build support for
multiple platforms into a single kernel.

Now the code is producing warnings when built with gcc-5.1:

drivers/tty/sysrq.c: In function 'sysrq_init':
drivers/tty/sysrq.c:959:33: warning: array subscript is above array bounds [-Warray-bounds]
   key = platform_sysrq_reset_seq[i];

We could fix this, but it seems unlikely that it will ever be used, so
let's just remove the code instead. We still have the option to pass the
sequence either in DT, using the kernel command line, or using the
/sys/module/sysrq/parameters/reset_seq file.

Fixes: 154b7a489a ("Input: sysrq - allow specifying alternate reset sequence")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Dmitry Torokhov 
Cc: Mark Brown 
Signed-off-by: Jiri Slaby

tty: Fix unsafe ldisc reference via ioctl(TIOCGETD)

2016-02-23T16:54:31+00:00

commit 5c17c861a357e9458001f021a7afa7aab9937439 upstream.

ioctl(TIOCGETD) retrieves the line discipline id directly from the
ldisc because the line discipline id (c_line) in termios is untrustworthy;
userspace may have set termios via ioctl(TCSETS*) without actually
changing the line discipline via ioctl(TIOCSETD).

However, directly accessing the current ldisc via tty->ldisc is
unsafe; the ldisc ptr dereferenced may be stale if the line discipline
is changing via ioctl(TIOCSETD) or hangup.

Wait for the line discipline reference (just like read() or write())
to retrieve the "current" line discipline id.

Signed-off-by: Peter Hurley 
Signed-off-by: Jiri Slaby