linux-stable.git/drivers/video/fbdev/core, branch v5.4.232

fbcon: Check font dimension limits

2023-02-22T11:50:27+00:00

commit 2b09d5d364986f724f17001ccfe4126b9b43a0be upstream.

blit_x and blit_y are u32, so fbcon currently cannot support fonts
larger than 32x32.

The 32x32 case also needs shifting an unsigned int, to properly set bit
31, otherwise we get "UBSAN: shift-out-of-bounds in fbcon_set_font",
as reported on:

http://lore.kernel.org/all/IA1PR07MB98308653E259A6F2CE94A4AFABCE9@IA1PR07MB9830.namprd07.prod.outlook.com
Kernel Branch: 6.2.0-rc5-next-20230124
Kernel config: https://drive.google.com/file/d/1F-LszDAizEEH0ZX0HcSR06v5q8FPl2Uv/view?usp=sharing
Reproducer: https://drive.google.com/file/d/1mP1jcLBY7vWCNM60OMf-ogw-urQRjNrm/view?usp=sharing

Reported-by: Sanan Hasanov 
Signed-off-by: Samuel Thibault 
Fixes: 2d2699d98492 ("fbcon: font setting should check limitation of driver")
Cc: stable@vger.kernel.org
Tested-by: Miko Larsson 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

fbcon: Use kzalloc() in fbcon_prepare_logo()

2022-12-14T10:30:41+00:00

[ Upstream commit a6a00d7e8ffd78d1cdb7a43f1278f081038c638f ]

A kernel built with syzbot's config file reported that

  scr_memcpyw(q, save, array3_size(logo_lines, new_cols, 2))

causes uninitialized "save" to be copied.

  ----------
  [drm] Initialized vgem 1.0.0 20120112 for vgem on minor 0
  [drm] Initialized vkms 1.0.0 20180514 for vkms on minor 1
  Console: switching to colour frame buffer device 128x48
  =====================================================
  BUG: KMSAN: uninit-value in do_update_region+0x4b8/0xba0
   do_update_region+0x4b8/0xba0
   update_region+0x40d/0x840
   fbcon_switch+0x3364/0x35e0
   redraw_screen+0xae3/0x18a0
   do_bind_con_driver+0x1cb3/0x1df0
   do_take_over_console+0x11cb/0x13f0
   fbcon_fb_registered+0xacc/0xfd0
   register_framebuffer+0x1179/0x1320
   __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
   drm_fbdev_client_hotplug+0xbea/0xda0
   drm_fbdev_generic_setup+0x65e/0x9d0
   vkms_init+0x9f3/0xc76
   (...snipped...)

  Uninit was stored to memory at:
   fbcon_prepare_logo+0x143b/0x1940
   fbcon_init+0x2c1b/0x31c0
   visual_init+0x3e7/0x820
   do_bind_con_driver+0x14a4/0x1df0
   do_take_over_console+0x11cb/0x13f0
   fbcon_fb_registered+0xacc/0xfd0
   register_framebuffer+0x1179/0x1320
   __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
   drm_fbdev_client_hotplug+0xbea/0xda0
   drm_fbdev_generic_setup+0x65e/0x9d0
   vkms_init+0x9f3/0xc76
   (...snipped...)

  Uninit was created at:
   __kmem_cache_alloc_node+0xb69/0x1020
   __kmalloc+0x379/0x680
   fbcon_prepare_logo+0x704/0x1940
   fbcon_init+0x2c1b/0x31c0
   visual_init+0x3e7/0x820
   do_bind_con_driver+0x14a4/0x1df0
   do_take_over_console+0x11cb/0x13f0
   fbcon_fb_registered+0xacc/0xfd0
   register_framebuffer+0x1179/0x1320
   __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
   drm_fbdev_client_hotplug+0xbea/0xda0
   drm_fbdev_generic_setup+0x65e/0x9d0
   vkms_init+0x9f3/0xc76
   (...snipped...)

  CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc4-00356-g8f2975c2bb4c #924
  Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
  ----------

Signed-off-by: Tetsuo Handa 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/cad03d25-0ea0-32c4-8173-fd1895314bce@I-love.SAKURA.ne.jp
Signed-off-by: Sasha Levin

fbcon: Fix boundary checks for fbcon=vc:n1-n2 parameters

2022-08-25T09:17:22+00:00

commit cad564ca557f8d3bb3b1fa965d9a2b3f6490ec69 upstream.

The user may use the fbcon=vc:- option to tell fbcon to take
over the given range (n1...n2) of consoles. The value for n1 and n2
needs to be a positive number and up to (MAX_NR_CONSOLES - 1).
The given values were not fully checked against those boundaries yet.

To fix the issue, convert first_fb_vc and last_fb_vc to unsigned
integers and check them against the upper boundary, and make sure that
first_fb_vc is smaller than last_fb_vc.

Cc: stable@vger.kernel.org # v4.19+
Reviewed-by: Daniel Vetter 
Signed-off-by: Helge Deller 
Link: https://patchwork.freedesktop.org/patch/msgid/YpkYRMojilrtZIgM@p100
Signed-off-by: Greg Kroah-Hartman

fbcon: Prevent that screen size is smaller than font size

2022-07-12T14:30:47+00:00

commit e64242caef18b4a5840b0e7a9bff37abd4f4f933 upstream.

We need to prevent that users configure a screen size which is smaller than the
currently selected font size. Otherwise rendering chars on the screen will
access memory outside the graphics memory region.

This patch adds a new function fbcon_modechange_possible() which
implements this check and which later may be extended with other checks
if necessary.  The new function is called from the FBIOPUT_VSCREENINFO
ioctl handler in fbmem.c, which will return -EINVAL if userspace asked
for a too small screen size.

Signed-off-by: Helge Deller 
Reviewed-by: Geert Uytterhoeven 
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Greg Kroah-Hartman

fbcon: Disallow setting font bigger than screen size

2022-07-12T14:30:47+00:00

commit 65a01e601dbba8b7a51a2677811f70f783766682 upstream.

Prevent that users set a font size which is bigger than the physical screen.
It's unlikely this may happen (because screens are usually much larger than the
fonts and each font char is limited to 32x32 pixels), but it may happen on
smaller screens/LCD displays.

Signed-off-by: Helge Deller 
Reviewed-by: Daniel Vetter 
Reviewed-by: Geert Uytterhoeven 
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Greg Kroah-Hartman

fbmem: Check virtual screen sizes in fb_set_var()

2022-07-12T14:30:47+00:00

commit 6c11df58fd1ac0aefcb3b227f72769272b939e56 upstream.

Verify that the fbdev or drm driver correctly adjusted the virtual
screen sizes. On failure report the failing driver and reject the screen
size change.

Signed-off-by: Helge Deller 
Reviewed-by: Geert Uytterhoeven 
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Greg Kroah-Hartman

fbdev: fbmem: Fix logo center image dx issue

2022-07-12T14:30:46+00:00

commit 955f04766d4e6eb94bf3baa539e096808c74ebfb upstream.

Image.dx gets wrong value because of missing '()'.

If xres == logo->width and n == 1, image.dx = -16.

Signed-off-by: Guiling Deng 
Fixes: 3d8b1933eb1c ("fbdev: fbmem: add config option to center the bootup logo")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

fbcon: Consistently protect deferred_takeover with console_lock()

2022-06-14T16:11:25+00:00

[ Upstream commit 43553559121ca90965b572cf8a1d6d0fd618b449 ]

This shouldn't be a problem in practice since until we've actually
taken over the console there's nothing we've registered with the
console/vt subsystem, so the exit/unbind path that check this can't
do the wrong thing. But it's confusing, so fix it by moving it a tad
later.

Acked-by: Sam Ravnborg 
Signed-off-by: Daniel Vetter 
Cc: Daniel Vetter 
Cc: Du Cheng 
Cc: Tetsuo Handa 
Cc: Claudio Suarez 
Cc: Thomas Zimmermann 
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-14-daniel.vetter@ffwll.ch
Signed-off-by: Sasha Levin

video: fbdev: fbcvt.c: fix printing in fb_cvt_print_name()

2022-04-15T12:18:07+00:00

[ Upstream commit 78482af095abd9f4f29f1aa3fe575d25c6ae3028 ]

This code has two bugs:
1) "cnt" is 255 but the size of the buffer is 256 so the last byte is
   not used.
2) If we try to print more than 255 characters then "cnt" will be
   negative and that will trigger a WARN() in snprintf(). The fix for
   this is to use scnprintf() instead of snprintf().

We can re-write this code to be cleaner:
1) Rename "offset" to "off" because that's shorter.
2) Get rid of the "cnt" variable and just use "size - off" directly.
3) Get rid of the "read" variable and just increment "off" directly.

Fixes: 96fe6a2109db ("fbdev: Add VESA Coordinated Video Timings (CVT) support")
Signed-off-by: Dan Carpenter 
Signed-off-by: Helge Deller 
Signed-off-by: Sasha Levin

fbmem: don't allow too huge resolutions

2021-09-15T07:47:41+00:00

commit 8c28051cdcbe9dfcec6bd0a4709d67a09df6edae upstream.

syzbot is reporting page fault at vga16fb_fillrect() [1], for
vga16fb_check_var() is failing to detect multiplication overflow.

  if (vxres * vyres > maxmem) {
    vyres = maxmem / vxres;
    if (vyres < yres)
      return -ENOMEM;
  }

Since no module would accept too huge resolutions where multiplication
overflow happens, let's reject in the common path.

Link: https://syzkaller.appspot.com/bug?extid=04168c8063cfdde1db5e [1]
Reported-by: syzbot 
Debugged-by: Randy Dunlap 
Signed-off-by: Tetsuo Handa 
Reviewed-by: Geert Uytterhoeven 
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/185175d6-227a-7b55-433d-b070929b262c@i-love.sakura.ne.jp
Signed-off-by: Greg Kroah-Hartman