<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/video/fbdev/core, branch v4.14.331</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>fbcon: Fix null-ptr-deref in soft_cursor</title>
<updated>2023-06-09T08:22:54+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2023-05-27T06:41:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7ecfde036ab3f4f23cb888955643a35ae504e25f'/>
<id>7ecfde036ab3f4f23cb888955643a35ae504e25f</id>
<content type='text'>
commit d78bd6cc68276bd57f766f7cb98bfe32c23ab327 upstream.

syzbot repored this bug in the softcursor code:

BUG: KASAN: null-ptr-deref in soft_cursor+0x384/0x6b4 drivers/video/fbdev/core/softcursor.c:70
Read of size 16 at addr 0000000000000200 by task kworker/u4:1/12

CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.4.0-rc3-syzkaller-geb0f1697d729 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: events_power_efficient fb_flashcursor
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_report+0xe4/0x514 mm/kasan/report.c:465
 kasan_report+0xd4/0x130 mm/kasan/report.c:572
 kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:187
 __asan_memcpy+0x3c/0x84 mm/kasan/shadow.c:105
 soft_cursor+0x384/0x6b4 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x113c/0x1a64 drivers/video/fbdev/core/bitblit.c:377
 fb_flashcursor+0x35c/0x54c drivers/video/fbdev/core/fbcon.c:380
 process_one_work+0x788/0x12d4 kernel/workqueue.c:2405
 worker_thread+0x8e0/0xfe8 kernel/workqueue.c:2552
 kthread+0x288/0x310 kernel/kthread.c:379
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:853

This fix let bit_cursor() bail out early when a font bitmap
isn't available yet.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Reported-by: syzbot+d910bd780e6efac35869@syzkaller.appspotmail.com
Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d78bd6cc68276bd57f766f7cb98bfe32c23ab327 upstream.

syzbot repored this bug in the softcursor code:

BUG: KASAN: null-ptr-deref in soft_cursor+0x384/0x6b4 drivers/video/fbdev/core/softcursor.c:70
Read of size 16 at addr 0000000000000200 by task kworker/u4:1/12

CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.4.0-rc3-syzkaller-geb0f1697d729 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: events_power_efficient fb_flashcursor
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_report+0xe4/0x514 mm/kasan/report.c:465
 kasan_report+0xd4/0x130 mm/kasan/report.c:572
 kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:187
 __asan_memcpy+0x3c/0x84 mm/kasan/shadow.c:105
 soft_cursor+0x384/0x6b4 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x113c/0x1a64 drivers/video/fbdev/core/bitblit.c:377
 fb_flashcursor+0x35c/0x54c drivers/video/fbdev/core/fbcon.c:380
 process_one_work+0x788/0x12d4 kernel/workqueue.c:2405
 worker_thread+0x8e0/0xfe8 kernel/workqueue.c:2552
 kthread+0x288/0x310 kernel/kthread.c:379
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:853

This fix let bit_cursor() bail out early when a font bitmap
isn't available yet.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Reported-by: syzbot+d910bd780e6efac35869@syzkaller.appspotmail.com
Acked-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: modedb: Add 1920x1080 at 60 Hz video mode</title>
<updated>2023-06-09T08:22:49+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2023-04-22T21:24:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a7155cc23a70cfb5d1b361eabbb84191048bc4ce'/>
<id>a7155cc23a70cfb5d1b361eabbb84191048bc4ce</id>
<content type='text'>
[ Upstream commit c8902258b2b8ecaa1b8d88c312853c5b14c2553d ]

Add typical resolution for Full-HD monitors.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c8902258b2b8ecaa1b8d88c312853c5b14c2553d ]

Add typical resolution for Full-HD monitors.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbcon: Check font dimension limits</title>
<updated>2023-02-22T11:46:02+00:00</updated>
<author>
<name>Samuel Thibault</name>
<email>samuel.thibault@ens-lyon.org</email>
</author>
<published>2023-01-29T15:17:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7625513267a2b155a5e31e4ac443bf954591b7fa'/>
<id>7625513267a2b155a5e31e4ac443bf954591b7fa</id>
<content type='text'>
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 &lt;sanan.hasanov@Knights.ucf.edu&gt;
Signed-off-by: Samuel Thibault &lt;samuel.thibault@ens-lyon.org&gt;
Fixes: 2d2699d98492 ("fbcon: font setting should check limitation of driver")
Cc: stable@vger.kernel.org
Tested-by: Miko Larsson &lt;mikoxyzzz@gmail.com&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;sanan.hasanov@Knights.ucf.edu&gt;
Signed-off-by: Samuel Thibault &lt;samuel.thibault@ens-lyon.org&gt;
Fixes: 2d2699d98492 ("fbcon: font setting should check limitation of driver")
Cc: stable@vger.kernel.org
Tested-by: Miko Larsson &lt;mikoxyzzz@gmail.com&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbcon: Disallow setting font bigger than screen size</title>
<updated>2022-07-12T14:27:28+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2022-06-25T10:56:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f7e7c2ad446f359f54f4ea6a0a30b218e5edf134'/>
<id>f7e7c2ad446f359f54f4ea6a0a30b218e5edf134</id>
<content type='text'>
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 &lt;deller@gmx.de&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;deller@gmx.de&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: fbdev: fbcvt.c: fix printing in fb_cvt_print_name()</title>
<updated>2022-04-20T07:08:14+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2021-09-16T13:29:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=817cd6ad4c2057fafaf57bf98548b3a9650fc714'/>
<id>817cd6ad4c2057fafaf57bf98548b3a9650fc714</id>
<content type='text'>
[ 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 &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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 &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbmem: don't allow too huge resolutions</title>
<updated>2021-09-22T09:45:23+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@i-love.sakura.ne.jp</email>
</author>
<published>2021-09-08T10:27:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0a3be6a03a1cea8a02af944087d81b86a32a3941'/>
<id>0a3be6a03a1cea8a02af944087d81b86a32a3941</id>
<content type='text'>
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 &gt; maxmem) {
    vyres = maxmem / vxres;
    if (vyres &lt; 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 &lt;syzbot+04168c8063cfdde1db5e@syzkaller.appspotmail.com&gt;
Debugged-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/185175d6-227a-7b55-433d-b070929b262c@i-love.sakura.ne.jp
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &gt; maxmem) {
    vyres = maxmem / vxres;
    if (vyres &lt; 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 &lt;syzbot+04168c8063cfdde1db5e@syzkaller.appspotmail.com&gt;
Debugged-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/185175d6-227a-7b55-433d-b070929b262c@i-love.sakura.ne.jp
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbmem: add margin check to fb_check_caps()</title>
<updated>2021-09-03T07:56:26+00:00</updated>
<author>
<name>George Kennedy</name>
<email>george.kennedy@oracle.com</email>
</author>
<published>2020-07-07T19:26:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=688dffd8db440196d33b801ad641036954125100'/>
<id>688dffd8db440196d33b801ad641036954125100</id>
<content type='text'>
commit a49145acfb975d921464b84fe00279f99827d816 upstream.

A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting
or yres setting in struct fb_var_screeninfo will result in a
KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as
the margins are being cleared. The margins are cleared in
chunks and if the xres setting or yres setting is a value of
zero upto the chunk size, the failure will occur.

Add a margin check to validate xres and yres settings.

Signed-off-by: George Kennedy &lt;george.kennedy@oracle.com&gt;
Reported-by: syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com
Reviewed-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: Dhaval Giani &lt;dhaval.giani@oracle.com&gt;
Signed-off-by: Bartlomiej Zolnierkiewicz &lt;b.zolnierkie@samsung.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1594149963-13801-1-git-send-email-george.kennedy@oracle.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a49145acfb975d921464b84fe00279f99827d816 upstream.

A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting
or yres setting in struct fb_var_screeninfo will result in a
KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as
the margins are being cleared. The margins are cleared in
chunks and if the xres setting or yres setting is a value of
zero upto the chunk size, the failure will occur.

Add a margin check to validate xres and yres settings.

Signed-off-by: George Kennedy &lt;george.kennedy@oracle.com&gt;
Reported-by: syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com
Reviewed-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: Dhaval Giani &lt;dhaval.giani@oracle.com&gt;
Signed-off-by: Bartlomiej Zolnierkiewicz &lt;b.zolnierkie@samsung.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1594149963-13801-1-git-send-email-george.kennedy@oracle.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tty: vt: always invoke vc-&gt;vc_sw-&gt;con_resize callback</title>
<updated>2021-05-26T09:47:01+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2021-05-15T03:00:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=63913d1d8106171918989ffdb2a11308f795fdc9'/>
<id>63913d1d8106171918989ffdb2a11308f795fdc9</id>
<content type='text'>
commit ffb324e6f874121f7dce5bdae5e05d02baae7269 upstream.

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 &lt;sys/types.h&gt;
  #include &lt;sys/stat.h&gt;
  #include &lt;fcntl.h&gt;
  #include &lt;sys/ioctl.h&gt;
  #include &lt;linux/kd.h&gt;
  #include &lt;linux/vt.h&gt;

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

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

Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1]
Reported-by: syzbot &lt;syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com&gt;
Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Tested-by: syzbot &lt;syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
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<pre>
commit ffb324e6f874121f7dce5bdae5e05d02baae7269 upstream.

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 &lt;sys/types.h&gt;
  #include &lt;sys/stat.h&gt;
  #include &lt;fcntl.h&gt;
  #include &lt;sys/ioctl.h&gt;
  #include &lt;linux/kd.h&gt;
  #include &lt;linux/vt.h&gt;

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

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

Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1]
Reported-by: syzbot &lt;syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com&gt;
Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Tested-by: syzbot &lt;syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: zero-fill colormap in fbcmap.c</title>
<updated>2021-05-22T08:57:15+00:00</updated>
<author>
<name>Phillip Potter</name>
<email>phil@philpotter.co.uk</email>
</author>
<published>2021-03-31T22:07:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5db5917987a602074bc2c4ba7670225c503d921a'/>
<id>5db5917987a602074bc2c4ba7670225c503d921a</id>
<content type='text'>
commit 19ab233989d0f7ab1de19a036e247afa4a0a1e9c upstream.

Use kzalloc() rather than kmalloc() for the dynamically allocated parts
of the colormap in fb_alloc_cmap_gfp, to prevent a leak of random kernel
data to userspace under certain circumstances.

Fixes a KMSAN-found infoleak bug reported by syzbot at:
https://syzkaller.appspot.com/bug?id=741578659feabd108ad9e06696f0c1f2e69c4b6e

Reported-by: syzbot+47fa9c9c648b765305b9@syzkaller.appspotmail.com
Cc: stable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Phillip Potter &lt;phil@philpotter.co.uk&gt;
Link: https://lore.kernel.org/r/20210331220719.1499743-1-phil@philpotter.co.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
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<pre>
commit 19ab233989d0f7ab1de19a036e247afa4a0a1e9c upstream.

Use kzalloc() rather than kmalloc() for the dynamically allocated parts
of the colormap in fb_alloc_cmap_gfp, to prevent a leak of random kernel
data to userspace under certain circumstances.

Fixes a KMSAN-found infoleak bug reported by syzbot at:
https://syzkaller.appspot.com/bug?id=741578659feabd108ad9e06696f0c1f2e69c4b6e

Reported-by: syzbot+47fa9c9c648b765305b9@syzkaller.appspotmail.com
Cc: stable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Phillip Potter &lt;phil@philpotter.co.uk&gt;
Link: https://lore.kernel.org/r/20210331220719.1499743-1-phil@philpotter.co.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers: video: fbcon: fix NULL dereference in fbcon_cursor()</title>
<updated>2021-04-07T10:47:04+00:00</updated>
<author>
<name>Du Cheng</name>
<email>ducheng2@gmail.com</email>
</author>
<published>2021-03-12T08:14:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1e353852b3ae9baf9038cd377227526a3a239f20'/>
<id>1e353852b3ae9baf9038cd377227526a3a239f20</id>
<content type='text'>
commit 01faae5193d6190b7b3aa93dae43f514e866d652 upstream.

add null-check on function pointer before dereference on ops-&gt;cursor

Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Du Cheng &lt;ducheng2@gmail.com&gt;
Link: https://lore.kernel.org/r/20210312081421.452405-1-ducheng2@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 01faae5193d6190b7b3aa93dae43f514e866d652 upstream.

add null-check on function pointer before dereference on ops-&gt;cursor

Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Du Cheng &lt;ducheng2@gmail.com&gt;
Link: https://lore.kernel.org/r/20210312081421.452405-1-ducheng2@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
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