linux-stable.git/drivers/video/fbdev/core, branch v6.1.35

fbcon: Fix null-ptr-deref in soft_cursor

2023-06-09T08:34:26+00:00

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 
Reported-by: syzbot+d910bd780e6efac35869@syzkaller.appspotmail.com
Acked-by: Sam Ravnborg 
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman

fbdev: modedb: Add 1920x1080 at 60 Hz video mode

2023-06-09T08:34:09+00:00

[ Upstream commit c8902258b2b8ecaa1b8d88c312853c5b14c2553d ]

Add typical resolution for Full-HD monitors.

Signed-off-by: Helge Deller 
Signed-off-by: Sasha Levin

fbcon: set_con2fb_map needs to set con2fb_map!

2023-04-20T10:35:07+00:00

commit fffb0b52d5258554c645c966c6cbef7de50b851d upstream.

I got really badly confused in d443d9386472 ("fbcon: move more common
code into fb_open()") because we set the con2fb_map before the failure
points, which didn't look good.

But in trying to fix that I moved the assignment into the wrong path -
we need to do it for _all_ vc we take over, not just the first one
(which additionally requires the call to con2fb_acquire_newinfo).

I've figured this out because of a KASAN bug report, where the
fbcon_registered_fb and fbcon_display arrays went out of sync in
fbcon_mode_deleted() because the con2fb_map pointed at the old
fb_info, but the modes and everything was updated for the new one.

Signed-off-by: Daniel Vetter 
Reviewed-by: Javier Martinez Canillas 
Acked-by: Helge Deller 
Tested-by: Xingyuan Mo 
Fixes: d443d9386472 ("fbcon: move more common code into fb_open()")
Reported-by: Xingyuan Mo 
Cc: Thomas Zimmermann 
Cc: Sam Ravnborg 
Cc: Xingyuan Mo 
Cc: Thomas Zimmermann 
Cc: Helge Deller 
Cc:  # v5.19+
Signed-off-by: Greg Kroah-Hartman

fbcon: Fix error paths in set_con2fb_map

2023-04-20T10:35:07+00:00

commit edf79dd2172233452ff142dcc98b19d955fc8974 upstream.

This is a regressoin introduced in b07db3958485 ("fbcon: Ditch error
handling for con2fb_release_oldinfo"). I failed to realize what the if
(!err) checks. The mentioned commit was dropping the
con2fb_release_oldinfo() return value but the if (!err) was also
checking whether the con2fb_acquire_newinfo() function call above
failed or not.

Fix this with an early return statement.

Note that there's still a difference compared to the orginal state of
the code, the below lines are now also skipped on error:

	if (!search_fb_in_map(info_idx))
		info_idx = newidx;

These are only needed when we've actually thrown out an old fb_info
from the console mappings, which only happens later on.

Also move the fbcon_add_cursor_work() call into the same if block,
it's all protected by console_lock so doesn't matter when we set up
the blinking cursor delayed work anyway. This further simplifies the
control flow and allows us to ditch the found local variable.

v2: Clarify commit message (Javier)

Signed-off-by: Daniel Vetter 
Reviewed-by: Javier Martinez Canillas 
Acked-by: Helge Deller 
Tested-by: Xingyuan Mo 
Fixes: b07db3958485 ("fbcon: Ditch error handling for con2fb_release_oldinfo")
Cc: Thomas Zimmermann 
Cc: Sam Ravnborg 
Cc: Xingyuan Mo 
Cc: Thomas Zimmermann 
Cc: Helge Deller 
Cc:  # v5.19+
Signed-off-by: Greg Kroah-Hartman

fbmem: Reject FB_ACTIVATE_KD_TEXT from userspace

2023-04-20T10:35:06+00:00

commit 6fd33a3333c7916689b8f051a185defe4dd515b0 upstream.

This is an oversight from dc5bdb68b5b3 ("drm/fb-helper: Fix vt
restore") - I failed to realize that nasty userspace could set this.

It's not pretty to mix up kernel-internal and userspace uapi flags
like this, but since the entire fb_var_screeninfo structure is uapi
we'd need to either add a new parameter to the ->fb_set_par callback
and fb_set_par() function, which has a _lot_ of users. Or some other
fairly ugly side-channel int fb_info. Neither is a pretty prospect.

Instead just correct the issue at hand by filtering out this
kernel-internal flag in the ioctl handling code.

Reviewed-by: Javier Martinez Canillas 
Acked-by: Maarten Lankhorst 
Signed-off-by: Daniel Vetter 
Fixes: dc5bdb68b5b3 ("drm/fb-helper: Fix vt restore")
Cc: Alex Deucher 
Cc: shlomo@fastmail.com
Cc: Michel Dänzer 
Cc: Noralf Trønnes 
Cc: Thomas Zimmermann 
Cc: Daniel Vetter 
Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: dri-devel@lists.freedesktop.org
Cc:  # v5.7+
Cc: Bartlomiej Zolnierkiewicz 
Cc: Geert Uytterhoeven 
Cc: Nathan Chancellor 
Cc: Qiujun Huang 
Cc: Peter Rosin 
Cc: linux-fbdev@vger.kernel.org
Cc: Helge Deller 
Cc: Sam Ravnborg 
Cc: Geert Uytterhoeven 
Cc: Samuel Thibault 
Cc: Tetsuo Handa 
Cc: Shigeru Yoshida 
Link: https://patchwork.freedesktop.org/patch/msgid/20230404193934.472457-1-daniel.vetter@ffwll.ch
Signed-off-by: Greg Kroah-Hartman

fbdev: Fix incorrect page mapping clearance at fb_deferred_io_release()

2023-03-22T12:34:04+00:00

commit fe9ae05cfbe587dda724fcf537c00bc2f287da62 upstream.

The recent fix for the deferred I/O by the commit
  3efc61d95259 ("fbdev: Fix invalid page access after closing deferred I/O devices")
caused a regression when the same fb device is opened/closed while
it's being used.  It resulted in a frozen screen even if something
is redrawn there after the close.  The breakage is because the patch
was made under a wrong assumption of a single open; in the current
code, fb_deferred_io_release() cleans up the page mapping of the
pageref list and it calls cancel_delayed_work_sync() unconditionally,
where both are no correct behavior for multiple opens.

This patch adds a refcount for the opens of the device, and applies
the cleanup only when all files get closed.

As both fb_deferred_io_open() and _close() are called always in the
fb_info lock (mutex), it's safe to use the normal int for the
refcounting.

Also, a useless BUG_ON() is dropped.

Fixes: 3efc61d95259 ("fbdev: Fix invalid page access after closing deferred I/O devices")
Cc: 
Signed-off-by: Takashi Iwai 
Reviewed-by: Patrik Jakobsson 
Signed-off-by: Thomas Zimmermann 
Link: https://patchwork.freedesktop.org/patch/msgid/20230308105012.1845-1-tiwai@suse.de
Signed-off-by: Greg Kroah-Hartman

Revert "fbcon: don't lose the console font across generic->chip driver switch"

2023-03-10T08:33:56+00:00

[ Upstream commit 12d5796d55f9fd9e4b621003127c99e176665064 ]

This reverts commit ae1287865f5361fa138d4d3b1b6277908b54eac9.

Always free the console font when deinitializing the framebuffer
console. Subsequent framebuffer consoles will then use the default
font. Rely on userspace to load any user-configured font for these
consoles.

Commit ae1287865f53 ("fbcon: don't lose the console font across
generic->chip driver switch") was introduced to work around losing
the font during graphics-device handover. [1][2] It kept a dangling
pointer with the font data between loading the two consoles, which is
fairly adventurous hack. It also never covered cases when the other
consoles, such as VGA text mode, where involved.

The problem has meanwhile been solved in userspace. Systemd comes
with a udev rule that re-installs the configured font when a console
comes up. [3] So the kernel workaround can be removed.

This also removes one of the two special cases triggered by setting
FBINFO_MISC_FIRMWARE in an fbdev driver.

Tested during device handover from efifb and simpledrm to radeon. Udev
reloads the configured console font for the new driver's terminal.

Signed-off-by: Thomas Zimmermann
Link: https://bugzilla.redhat.com/show_bug.cgi?id=892340 # 1
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1074624 # 2
Link: https://cgit.freedesktop.org/systemd/systemd/tree/src/vconsole/90-vconsole.rules.in?h=v222 # 3
Reviewed-by: Javier Martinez Canillas
Link: https://patchwork.freedesktop.org/patch/msgid/20221219160516.23436-3-tzimmermann@suse.de
Signed-off-by: Sasha Levin

fbdev: Fix invalid page access after closing deferred I/O devices

2023-02-22T11:59:46+00:00

commit 3efc61d95259956db25347e2a9562c3e54546e20 upstream.

When a fbdev with deferred I/O is once opened and closed, the dirty
pages still remain queued in the pageref list, and eventually later
those may be processed in the delayed work.  This may lead to a
corruption of pages, hitting an Oops.

This patch makes sure to cancel the delayed work and clean up the
pageref list at closing the device for addressing the bug.  A part of
the cleanup code is factored out as a new helper function that is
called from the common fb_release().

Reviewed-by: Patrik Jakobsson 
Cc: 
Signed-off-by: Takashi Iwai 
Tested-by: Miko Larsson 
Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct")
Reviewed-by: Thomas Zimmermann 
Signed-off-by: Thomas Zimmermann 
Link: https://patchwork.freedesktop.org/patch/msgid/20230129082856.22113-1-tiwai@suse.de
Signed-off-by: Greg Kroah-Hartman

fbcon: Check font dimension limits

2023-02-09T10:28:15+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

fbdev: fbcon: release buffer when fbcon_do_set_font() failed

2022-12-31T12:33:11+00:00

commit 3c3bfb8586f848317ceba5d777e11204ba3e5758 upstream.

syzbot is reporting memory leak at fbcon_do_set_font() [1], for
commit a5a923038d70 ("fbdev: fbcon: Properly revert changes when
vc_resize() failed") missed that the buffer might be newly allocated
by fbcon_set_font().

Link: https://syzkaller.appspot.com/bug?extid=25bdb7b1703639abd498 [1]
Reported-by: syzbot 
Signed-off-by: Tetsuo Handa 
Tested-by: syzbot 
Fixes: a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman