linux-stable.git/drivers/video/fbdev/core/fbcon.c, branch v6.14

fbcon: break earlier in search_fb_in_map and search_for_mapped_con

2024-09-26T16:25:12+00:00

Break the for loop immediately upon finding the target, making the
process more efficient.

Signed-off-by: Qianqiang Liu 
Signed-off-by: Helge Deller

fbcon: Fix a NULL pointer dereference issue in fbcon_putcs

2024-09-26T16:20:27+00:00

syzbot has found a NULL pointer dereference bug in fbcon.
Here is the simplified C reproducer:

struct param {
	uint8_t type;
	struct tiocl_selection ts;
};

int main()
{
	struct fb_con2fbmap con2fb;
	struct param param;

	int fd = open("/dev/fb1", 0, 0);

	con2fb.console = 0x19;
	con2fb.framebuffer = 0;
	ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);

	param.type = 2;
	param.ts.xs = 0; param.ts.ys = 0;
	param.ts.xe = 0; param.ts.ye = 0;
	param.ts.sel_mode = 0;

	int fd1 = open("/dev/tty1", O_RDWR, 0);
	ioctl(fd1, TIOCLINUX, ¶m);

	con2fb.console = 1;
	con2fb.framebuffer = 0;
	ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);

	return 0;
}

After calling ioctl(fd1, TIOCLINUX, ¶m), the subsequent ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb)
causes the kernel to follow a different execution path:

 set_con2fb_map
  -> con2fb_init_display
   -> fbcon_set_disp
    -> redraw_screen
     -> hide_cursor
      -> clear_selection
       -> highlight
        -> invert_screen
         -> do_update_region
          -> fbcon_putcs
           -> ops->putcs

Since ops->putcs is a NULL pointer, this leads to a kernel panic.
To prevent this, we need to call set_blitting_type() within set_con2fb_map()
to properly initialize ops->putcs.

Reported-by: syzbot+3d613ae53c031502687a@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=3d613ae53c031502687a
Tested-by: syzbot+3d613ae53c031502687a@syzkaller.appspotmail.com
Signed-off-by: Qianqiang Liu 
Signed-off-by: Helge Deller

fbcon: Use oops_in_progress instead of panic_cpu

2024-07-22T15:51:29+00:00

Panic_cpu is not exported, so it can't be used if fbcon is used as
a module. Use oops_in_progress in this case, but non-fatal oops won't
be printed.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202407210203.2ISiIC9m-lkp@intel.com/
Signed-off-by: Jocelyn Falempe 
Reviewed-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20240722114800.174558-1-jfalempe@redhat.com

fbcon: Add an option to disable fbcon in panic

2024-07-19T09:38:23+00:00

This is required to avoid conflict between DRM_PANIC, and fbcon. If
a drm device already handle panic with drm_panic, it should set
the skip_panic field in fb_info, so that fbcon will stay quiet, and
not overwrite the panic_screen.

Signed-off-by: Jocelyn Falempe 
Reviewed-by: Javier Martinez Canillas 
Reviewed-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20240717090102.968152-3-jfalempe@redhat.com

arch: Remove struct fb_info from video helpers

2024-05-03T15:07:50+00:00

The per-architecture video helpers do not depend on struct fb_info
or anything else from fbdev. Remove it from the interface and replace
fb_is_primary_device() with video_is_primary_device(). The new helper
is similar in functionality, but can operate on non-fbdev devices.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Sam Ravnborg 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: "David S. Miller" 
Cc: Andreas Larsson 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Signed-off-by: Arnd Bergmann

Merge tag 'fbdev-for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev

2024-03-22T17:09:08+00:00

Pull fbdev updates from Helge Deller:

 - Allow console fonts up to 64x128 pixels (Samuel Thibault)

 - Prevent division-by-zero in fb monitor code (Roman Smirnov)

 - Drop Renesas ARM platforms from Mobile LCDC framebuffer driver (Geert
   Uytterhoeven)

 - Various code cleanups in viafb, uveafb and mb862xxfb drivers by
   Aleksandr Burakov, Li Zhijian and Michael Ellerman

* tag 'fbdev-for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev:
  fbdev: panel-tpo-td043mtea1: Convert sprintf() to sysfs_emit()
  fbmon: prevent division by zero in fb_videomode_from_videomode()
  fbcon: Increase maximum font width x height to 64 x 128
  fbdev: viafb: fix typo in hw_bitblt_1 and hw_bitblt_2
  fbdev: mb862xxfb: Fix defined but not used error
  fbdev: uvesafb: Convert sprintf/snprintf to sysfs_emit
  fbdev: Restrict FB_SH_MOBILE_LCDC to SuperH

Merge tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2024-03-21T19:44:10+00:00

Pull tty / serial driver updates from Greg KH:
 "Here is the big set of TTY/Serial driver updates and cleanups for
  6.9-rc1. Included in here are:

   - more tty cleanups from Jiri

   - loads of 8250 driver cleanups from Andy

   - max310x driver updates

   - samsung serial driver updates

   - uart_prepare_sysrq_char() updates for many drivers

   - platform driver remove callback void cleanups

   - stm32 driver updates

   - other small tty/serial driver updates

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

* tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
  dt-bindings: serial: stm32: add power-domains property
  serial: 8250_dw: Replace ACPI device check by a quirk
  serial: Lock console when calling into driver before registration
  serial: 8250_uniphier: Switch to use uart_read_port_properties()
  serial: 8250_tegra: Switch to use uart_read_port_properties()
  serial: 8250_pxa: Switch to use uart_read_port_properties()
  serial: 8250_omap: Switch to use uart_read_port_properties()
  serial: 8250_of: Switch to use uart_read_port_properties()
  serial: 8250_lpc18xx: Switch to use uart_read_port_properties()
  serial: 8250_ingenic: Switch to use uart_read_port_properties()
  serial: 8250_dw: Switch to use uart_read_port_properties()
  serial: 8250_bcm7271: Switch to use uart_read_port_properties()
  serial: 8250_bcm2835aux: Switch to use uart_read_port_properties()
  serial: 8250_aspeed_vuart: Switch to use uart_read_port_properties()
  serial: port: Introduce a common helper to read properties
  serial: core: Add UPIO_UNKNOWN constant for unknown port type
  serial: core: Move struct uart_port::quirks closer to possible values
  serial: sh-sci: Call sci_serial_{in,out}() directly
  serial: core: only stop transmit when HW fifo is empty
  serial: pch: Use uart_prepare_sysrq_char().
  ...

fbcon: Increase maximum font width x height to 64 x 128

2024-03-16T07:29:48+00:00

By using bitmaps we actually support whatever size we would want, but
the console currently limits fonts to 64x128 (which gives 60x16 text on
4k screens), so we don't need more for now, and we can easily increase
later.

Signed-off-by: Samuel Thibault 
Signed-off-by: Helge Deller

fbcon: always restore the old font data in fbcon_do_set_font()

2024-02-26T15:47:02+00:00

Commit a5a923038d70 (fbdev: fbcon: Properly revert changes when
vc_resize() failed) started restoring old font data upon failure (of
vc_resize()). But it performs so only for user fonts. It means that the
"system"/internal fonts are not restored at all. So in result, the very
first call to fbcon_do_set_font() performs no restore at all upon
failing vc_resize().

This can be reproduced by Syzkaller to crash the system on the next
invocation of font_get(). It's rather hard to hit the allocation failure
in vc_resize() on the first font_set(), but not impossible. Esp. if
fault injection is used to aid the execution/failure. It was
demonstrated by Sirius:
  BUG: unable to handle page fault for address: fffffffffffffff8
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0
  Oops: 0000 [#1] PREEMPT SMP KASAN
  CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce #20
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286
  Call Trace:
   
   con_font_get drivers/tty/vt/vt.c:4558 [inline]
   con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673
   vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
   vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752
   tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803
   vfs_ioctl fs/ioctl.c:51 [inline]
  ...

So restore the font data in any case, not only for user fonts. Note the
later 'if' is now protected by 'old_userfont' and not 'old_data' as the
latter is always set now. (And it is supposed to be non-NULL. Otherwise
we would see the bug above again.)

Signed-off-by: Jiri Slaby (SUSE) 
Fixes: a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed")
Reported-and-tested-by: Ubisectech Sirius 
Cc: Ubisectech Sirius 
Cc: Daniel Vetter 
Cc: Helge Deller 
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20240208114411.14604-1-jirislaby@kernel.org

Merge 6.8-rc3 into tty-next

2024-02-04T14:21:02+00:00

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

Signed-off-by: Greg Kroah-Hartman