linux.git/drivers/tty/vt/vt.c, branch v5.9

Merge tag 'tty-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2020-08-26T17:58:20+00:00

Pull tty/serial fixes from Greg KH:
 "Here are a few small TTY/Serial/vt fixes for 5.9-rc3

  Included in here are:
   - qcom serial fixes
   - vt ioctl and core bugfixes
   - pl011 serial driver fixes
   - 8250 serial driver fixes
   - other misc serial driver fixes

  and for good measure:
   - fbcon fix for syzbot found problem.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: serial: imx: add dependence and build for earlycon
  serial: samsung: Removes the IRQ not found warning
  serial: 8250: change lock order in serial8250_do_startup()
  serial: stm32: avoid kernel warning on absence of optional IRQ
  serial: pl011: Fix oops on -EPROBE_DEFER
  serial: pl011: Don't leak amba_ports entry on driver register error
  serial: 8250_exar: Fix number of ports for Commtech PCIe cards
  tty: serial: qcom_geni_serial: Drop __init from qcom_geni_console_setup
  serial: qcom_geni_serial: Fix recent kdb hang
  vt_ioctl: change VT_RESIZEX ioctl to check for error return from vc_resize()
  fbcon: prevent user font height or width change from causing potential out-of-bounds access
  vt: defer kfree() of vc_screenbuf in vc_do_resize()

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva

vt: defer kfree() of vc_screenbuf in vc_do_resize()

2020-08-18T11:18:17+00:00

syzbot is reporting UAF bug in set_origin() from vc_do_resize() [1], for
vc_do_resize() calls kfree(vc->vc_screenbuf) before calling set_origin().

Unfortunately, in set_origin(), vc->vc_sw->con_set_origin() might access
vc->vc_pos when scroll is involved in order to manipulate cursor, but
vc->vc_pos refers already released vc->vc_screenbuf until vc->vc_pos gets
updated based on the result of vc->vc_sw->con_set_origin().

Preserving old buffer and tolerating outdated vc members until set_origin()
completes would be easier than preventing vc->vc_sw->con_set_origin() from
accessing outdated vc members.

[1] https://syzkaller.appspot.com/bug?id=6649da2081e2ebdc65c0642c214b27fe91099db3

Reported-by: syzbot 
Signed-off-by: Tetsuo Handa 
Cc: stable 
Link: https://lore.kernel.org/r/1596034621-4714-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman

Merge 5.8-rc7 into tty-next

2020-07-27T10:40:56+00:00

we need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

tty: vt: Replace HTTP links with HTTPS ones

2020-07-21T18:04:54+00:00

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov 
Link: https://lore.kernel.org/r/20200718133452.24290-1-grandmaster@al2klimov.de
Signed-off-by: Greg Kroah-Hartman

vt: Reject zero-sized screen buffer size.

2020-07-21T16:07:15+00:00

syzbot is reporting general protection fault in do_con_write() [1] caused
by vc->vc_screenbuf == ZERO_SIZE_PTR caused by vc->vc_screenbuf_size == 0
caused by vc->vc_cols == vc->vc_rows == vc->vc_size_row == 0 caused by
fb_set_var() from ioctl(FBIOPUT_VSCREENINFO) on /dev/fb0 , for
gotoxy(vc, 0, 0) from reset_terminal() from vc_init() from vc_allocate()
 from con_install() from tty_init_dev() from tty_open() on such console
causes vc->vc_pos == 0x10000000e due to
((unsigned long) ZERO_SIZE_PTR) + -1U * 0 + (-1U << 1).

I don't think that a console with 0 column or 0 row makes sense. And it
seems that vc_do_resize() does not intend to allow resizing a console to
0 column or 0 row due to

  new_cols = (cols ? cols : vc->vc_cols);
  new_rows = (lines ? lines : vc->vc_rows);

exception.

Theoretically, cols and rows can be any range as long as
0 < cols * rows * 2 <= KMALLOC_MAX_SIZE is satisfied (e.g.
cols == 1048576 && rows == 2 is possible) because of

  vc->vc_size_row = vc->vc_cols << 1;
  vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;

in visual_init() and kzalloc(vc->vc_screenbuf_size) in vc_allocate().

Since we can detect cols == 0 or rows == 0 via screenbuf_size = 0 in
visual_init(), we can reject kzalloc(0). Then, vc_allocate() will return
an error, and con_write() will not be called on a console with 0 column
or 0 row.

We need to make sure that integer overflow in visual_init() won't happen.
Since vc_do_resize() restricts cols <= 32767 and rows <= 32767, applying
1 <= cols <= 32767 and 1 <= rows <= 32767 restrictions to vc_allocate()
will be practically fine.

This patch does not touch con_init(), for returning -EINVAL there
does not help when we are not returning -ENOMEM.

[1] https://syzkaller.appspot.com/bug?extid=017265e8553724e514e8

Reported-and-tested-by: syzbot 
Signed-off-by: Tetsuo Handa 
Cc: stable 
Link: https://lore.kernel.org/r/20200712111013.11881-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman

vt: simplify noncolor attributes in build_attr

2020-06-24T15:08:33+00:00

All the attributes are bools, so do a simple shift instead of tests and
constants as bool is either 0 or 1.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200615074910.19267-28-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: remove superfluous parens in invert_screen and build_attr

2020-06-24T15:08:33+00:00

There were too many parentheses in invert_screen, remove them and align
the code in invert_screen a bit.

No functional change intended.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20200615074910.19267-27-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: use newly defined CUR_* macros

2020-06-24T15:08:33+00:00

We defined macros for all the magic constants in the previous patch. So
let us use the macro in the code now.

No functional change intended.

Signed-off-by: Jiri Slaby 
Cc: Thomas Winischhofer 
Cc: Bartlomiej Zolnierkiewicz 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: linux-usb@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Acked-by: Helge Deller 
Link: https://lore.kernel.org/r/20200615074910.19267-26-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: redefine world of cursor macros

2020-06-24T15:08:33+00:00

The cursor code used to use magic constants, ANDs, ORs, and some macros.
Redefine all this to make some sense.

In particular:
* Drop CUR_DEFAULT, which is CUR_UNDERLINE. CUR_DEFAULT was used only
  for cur_default variable initialization, so use CUR_UNDERLINE there to
  make obvious what's the default.
* Drop CUR_HWMASK. Instead, define CUR_SIZE() which explains it more.
  And use it all over the places.
* Define few more masks and bits which will be used in next patches
  instead of magic constants.
* Define CUR_MAKE to build up cursor value.

Signed-off-by: Jiri Slaby 
Cc: Bartlomiej Zolnierkiewicz 
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Link: https://lore.kernel.org/r/20200615074910.19267-25-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman