linux.git/drivers/tty/vt/vt.c, branch v5.19

vt: fix memory overlapping when deleting chars in the buffer

2022-06-30T15:17:40+00:00

A memory overlapping copy occurs when deleting a long line. This memory
overlapping copy can cause data corruption when scr_memcpyw is optimized
to memcpy because memcpy does not ensure its behavior if the destination
buffer overlaps with the source buffer. The line buffer is not always
broken, because the memcpy utilizes the hardware acceleration, whose
result is not deterministic.

Fix this problem by using replacing the scr_memcpyw with scr_memmovew.

Fixes: 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition")
Cc: stable 
Signed-off-by: Yangxi Xiang 
Link: https://lore.kernel.org/r/20220628093322.5688-1-xyangxi5@gmail.com
Signed-off-by: Greg Kroah-Hartman

tty: drivers/tty/, stop using tty_schedule_flip()

2021-11-25T17:35:23+00:00

Since commit a9c3f68f3cd8d (tty: Fix low_latency BUG) in 2014,
tty_flip_buffer_push() is only a wrapper to tty_schedule_flip(). We are
going to remove the latter (as it is used less), so call the former in
drivers/tty/.

Cc: Vladimir Zapolskiy 
Reviewed-by: Johan Hovold 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211122111648.30379-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

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

2021-09-01T16:51:16+00:00

Pull tty / serial updates from Greg KH:
 "Here is the "big" set of tty/serial driver patches for 5.15-rc1

  Nothing major in here at all, just some driver updates and more
  cleanups on old tty apis and code that needed it that includes:

   - tty.h cleanup of things that didn't belong in it

   - other tty cleanups by Jiri

   - driver cleanups

   - rs485 support added to amba-pl011 driver

   - dts updates

   - stm32 serial driver updates

   - other minor fixes and driver updates

  All have been in linux-next for a while with no reported problems"

* tag 'tty-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (83 commits)
  tty: serial: uartlite: Use read_poll_timeout for a polling loop
  tty: serial: uartlite: Use constants in early_uartlite_putc
  tty: Fix data race between tiocsti() and flush_to_ldisc()
  serial: vt8500: Use of_device_get_match_data
  serial: tegra: Use of_device_get_match_data
  serial: 8250_ingenic: Use of_device_get_match_data
  tty: serial: linflexuart: Remove redundant check to simplify the code
  tty: serial: fsl_lpuart: do software reset for imx7ulp and imx8qxp
  tty: serial: fsl_lpuart: enable two stop bits for lpuart32
  tty: serial: fsl_lpuart: fix the wrong mapbase value
  mxser: use semi-colons instead of commas
  tty: moxa: use semi-colons instead of commas
  tty: serial: fsl_lpuart: check dma_tx_in_progress in tx dma callback
  tty: replace in_irq() with in_hardirq()
  serial: sh-sci: fix break handling for sysrq
  serial: stm32: use devm_platform_get_and_ioremap_resource()
  serial: stm32: use the defined variable to simplify code
  Revert "arm pl011 serial: support multi-irq request"
  tty: serial: samsung: Add Exynos850 SoC data
  tty: serial: samsung: Fix driver data macros style
  ...

console: consume APC, DM, DCS

2021-08-30T15:29:04+00:00

The Linux console's VT102 implementation already consumes OSC
("Operating System Command") sequences, probably because that's how
palette changes are transmitted.

In addition to OSC, there are three other major clases of ANSI control
strings: APC ("Application Program Command"), PM ("Privacy Message"),
and DCS ("Device Control String").  They are handled similarly to OSC in
terms of termination.

Source: vt100.net

Add three new enumerated states, one for each of these types.  All three
are handled the same way right now--they simply consume input until
terminated.  I hope to expand upon this firmament in the future.  Add
new predicate ansi_control_string(), returning true for any of these
states.  Replace explicit checks against ESosc with calls to this
function.  Transition to these states appropriately from the escape
initiation (ESesc) state.

This was motivated by the following Notcurses bugs:

 https://github.com/dankamongmen/notcurses/issues/2050
 https://github.com/dankamongmen/notcurses/issues/1828
 https://github.com/dankamongmen/notcurses/issues/2069

where standard VT sequences are not consumed by the Linux console.  It's
not necessary that the Linux console *support* these sequences, but it
ought *consume* these well-specified classes of sequences.

Tested by sending a variety of escape sequences to the console, and
verifying that they still worked, or were now properly consumed.
Verified that the escapes were properly terminated at a generic level.
Verified that the Notcurses tools continued to show expected output on
the Linux console, except now without escape bleedthrough.

Link: https://lore.kernel.org/lkml/YSydL0q8iaUfkphg@schwarzgerat.orthanc/
Signed-off-by: nick black 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: Tetsuo Handa 
Cc: Daniel Vetter 
Signed-off-by: Linus Torvalds

tty: stop using alloc_tty_driver

2021-07-27T10:17:20+00:00

alloc_tty_driver was deprecated by tty_alloc_driver in commit
7f0bc6a68ed9 (TTY: pass flags to alloc_tty_driver) in 2012.

I never got into eliminating alloc_tty_driver until now. So we still
have two functions for allocating drivers which might be confusing. So
get rid of alloc_tty_driver uses to eliminate it for good in the next
patch.

Note we need to switch return value checking as tty_alloc_driver uses
ERR_PTR. And flags are now a parameter of tty_alloc_driver.

Cc: Richard Henderson (odd fixer:ALPHA PORT)
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Geert Uytterhoeven 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: Chris Zankel 
Cc: Max Filippov 
Cc: Samuel Iglesias Gonsalvez 
Cc: Jens Taprogge 
Cc: Karsten Keil 
Cc: Ulf Hansson 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Cc: Laurentiu Tudor 
Cc: Jiri Kosina 
Cc: David Sterba 
Cc: Shawn Guo 
Cc: Sascha Hauer 
Cc: Oliver Neukum 
Cc: Felipe Balbi 
Cc: Johan Hovold 
Cc: Marcel Holtmann 
Cc: Johan Hedberg 
Cc: Luiz Augusto von Dentz 
Acked-by: Samuel Iglesias Gonsálvez 
Acked-by: Max Filippov 
Acked-by: David Sterba 
Acked-by: Christian Borntraeger 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210723074317.32690-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: Fix out-of-bound vmalloc access in imageblit

2021-07-21T10:41:28+00:00

This issue happens when a userspace program does an ioctl
FBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct
containing only the fields xres, yres, and bits_per_pixel
with values.

If this struct is the same as the previous ioctl, the
vc_resize() detects it and doesn't call the resize_screen(),
leaving the fb_var_screeninfo incomplete. And this leads to
the updatescrollmode() calculates a wrong value to
fbcon_display->vrows, which makes the real_y() return a
wrong value of y, and that value, eventually, causes
the imageblit to access an out-of-bound address value.

To solve this issue I made the resize_screen() be called
even if the screen does not need any resizing, so it will
"fix and fill" the fb_var_screeninfo independently.

Cc: stable  # after 5.15-rc2 is out, give it time to bake
Reported-and-tested-by: syzbot+858dc7a2f7ef07c2c219@syzkaller.appspotmail.com
Signed-off-by: Igor Matheus Andrade Torrente 
Link: https://lore.kernel.org/r/20210628134509.15895-1-igormtorrente@gmail.com
Signed-off-by: Greg Kroah-Hartman

Merge 5.13-rc4 into tty-next

2021-05-31T07:44:28+00:00

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

Signed-off-by: Greg Kroah-Hartman

tty: vt: always invoke vc->vc_sw->con_resize callback

2021-05-15T15:12:12+00:00

syzbot is reporting OOB write at vga16fb_imageblit() [1], for
resize_screen() from ioctl(VT_RESIZE) returns 0 without checking whether
requested rows/columns fit the amount of memory reserved for the graphical
screen if current mode is KD_GRAPHICS.

----------
  #include 
  #include 
  #include 
  #include 
  #include 
  #include 

  int main(int argc, char *argv[])
  {
        const int fd = open("/dev/char/4:1", O_RDWR);
        struct vt_sizes vt = { 0x4100, 2 };

        ioctl(fd, KDSETMODE, KD_GRAPHICS);
        ioctl(fd, VT_RESIZE, &vt);
        ioctl(fd, KDSETMODE, KD_TEXT);
        return 0;
  }
----------

Allow framebuffer drivers to return -EINVAL, by moving vc->vc_mode !=
KD_GRAPHICS check from resize_screen() to fbcon_resize().

Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1]
Reported-by: syzbot 
Suggested-by: Linus Torvalds 
Signed-off-by: Tetsuo Handa 
Tested-by: syzbot 
Signed-off-by: Linus Torvalds

tty: remove tty_operations::chars_in_buffer for non-buffering

2021-05-13T16:29:11+00:00

The only user of tty_ops::chars_in_buffer is tty_chars_in_buffer. And it
considers tty_ops::chars_in_buffer optional. In case it's NULL, zero is
returned. So remove all those chars_in_buffer from tty_ops which return
zero. (Zero means such driver doesn't buffer.)

Signed-off-by: Jiri Slaby 
Cc: Richard Henderson 
Acked-by: Max Filippov  # xtensa
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Chris Zankel 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Link: https://lore.kernel.org/r/20210505091928.22010-26-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: make tty_operations::write_room return uint

2021-05-13T15:03:20+00:00

Line disciplines expect a positive value or zero returned from
tty->ops->write_room (invoked by tty_write_room). So make this
assumption explicit by using unsigned int as a return value. Both of
tty->ops->write_room and tty_write_room.

Signed-off-by: Jiri Slaby 
Acked-by: Laurentiu Tudor 
Acked-by: Alex Elder 
Acked-by: Max Filippov  # xtensa
Acked-by: David Sterba 
Acked-By: Anton Ivanov 
Acked-by: Geert Uytterhoeven 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Chris Zankel 
Cc: Arnd Bergmann 
Cc: Samuel Iglesias Gonsalvez 
Cc: Jens Taprogge 
Cc: Karsten Keil 
Cc: Scott Branden 
Cc: Ulf Hansson 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Cc: David Lin 
Cc: Johan Hovold 
Cc: Jiri Kosina 
Cc: Shawn Guo 
Cc: Sascha Hauer 
Cc: Oliver Neukum 
Cc: Felipe Balbi 
Cc: Mathias Nyman 
Cc: Marcel Holtmann 
Cc: Johan Hedberg 
Cc: Luiz Augusto von Dentz 
Link: https://lore.kernel.org/r/20210505091928.22010-23-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman