linux-stable.git/drivers/tty/vt, branch linux-3.2.y

tty: vt: fix up tabstops properly

2018-05-31T23:30:25+00:00

commit f1869a890cdedb92a3fab969db5d0fd982850273 upstream.

Tabs on a console with long lines do not wrap properly, so correctly
account for the line length when computing the tab placement location.

Reported-by: James Holderness 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

vt: fix unchecked __put_user() in tioclinux ioctls

2017-10-12T14:27:17+00:00

commit 6987dc8a70976561d22450b5858fc9767788cc1c upstream.

Only read access is checked before this call.

Actually, at the moment this is not an issue, as every in-tree arch does
the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU
to tell them apart, but this wasn't the case in the past and may happen
again on some odd arch in the future.

If anyone cares about 3.7 and earlier, this is a security hole (untested)
on real 80386 CPUs.

Signed-off-by: Adam Borowski 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

vt: clear selection before resizing

2017-02-23T03:50:56+00:00

commit 009e39ae44f4191188aeb6dfbf661b771dbbe515 upstream.

When resizing a vt its selection may exceed the new size, resulting in
an invalid memory access [1]. Clear the selection before resizing.

[1] http://lkml.kernel.org/r/CACT4Y+acDTwy4umEvf5ROBGiRJNrxHN4Cn5szCXE5Jw-d1B=Xw@mail.gmail.com

Reported-and-tested-by: Dmitry Vyukov 
Signed-off-by: Scot Doyle 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

tty: limit terminal size to 4M chars

2017-02-23T03:50:56+00:00

commit 32b2921e6a7461fe63b71217067a6cf4bddb132f upstream.

Size of kmalloc() in vc_do_resize() is controlled by user.
Too large kmalloc() size triggers WARNING message on console.
Put a reasonable upper bound on terminal size to prevent WARNINGs.

Signed-off-by: Dmitry Vyukov 
CC: David Rientjes 
Cc: One Thousand Gnomes 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: Peter Hurley 
Cc: linux-kernel@vger.kernel.org
Cc: syzkaller@googlegroups.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

tty: vt, fix bogus division in csi_J

2017-02-23T03:50:56+00:00

commit 42acfc6615f47e465731c263bee0c799edb098f2 upstream.

In csi_J(3), the third parameter of scr_memsetw (vc_screenbuf_size) is
divided by 2 inappropriatelly. But scr_memsetw expects size, not
count, because it divides the size by 2 on its own before doing actual
memset-by-words.

So remove the bogus division.

Signed-off-by: Jiri Slaby 
Cc: Petr Písař 
Fixes: f8df13e0a9 (tty: Clean console safely)
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

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

2016-11-20T01:01:27+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: Ben Hutchings

tty: vt, return error when con_startup fails

2016-08-22T21:37:09+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: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

vt: provide notifications on selection changes

2015-05-09T22:16:14+00:00

commit 19e3ae6b4f07a87822c1c9e7ed99d31860e701af upstream.

The vcs device's poll/fasync support relies on the vt notifier to signal
changes to the screen content.  Notifier invocations were missing for
changes that comes through the selection interface though.  Fix that.

Tested with BRLTTY 5.2.

Signed-off-by: Nicolas Pitre 
Cc: Dave Mielke 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

tty/vt: don't set font mappings on vc not supporting this

2014-12-14T16:23:55+00:00

commit 9e326f78713a4421fe11afc2ddeac07698fac131 upstream.

We can call this function for a dummy console that doesn't support
setting the font mapping, which will result in a null ptr BUG. So check
for this case and return error for consoles w/o font mapping support.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=59321
Signed-off-by: Imre Deak 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: this function doesn't take a lock, so doesn't
 need to unlock on error]
Signed-off-by: Ben Hutchings

vt: synchronize_rcu() under spinlock is not nice...

2013-04-10T02:20:03+00:00

commit e8cd81693bbbb15db57d3c9aa7dd90eda4842874 upstream.

vcs_poll_data_free() calls unregister_vt_notifier(), which calls
atomic_notifier_chain_unregister(), which calls synchronize_rcu().
Do it *after* we'd dropped ->f_lock.

Signed-off-by: Al Viro 
Signed-off-by: Ben Hutchings