<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/video/fbdev, branch v5.4.166</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>video: fbdev: chipsfb: use memset_io() instead of memset()</title>
<updated>2021-11-17T08:48:42+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-09-15T13:34:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d8241e7a214449fc332d78fa839775134a5b13ef'/>
<id>d8241e7a214449fc332d78fa839775134a5b13ef</id>
<content type='text'>
[ Upstream commit f2719b26ae27282c145202ffd656d5ff1fe737cc ]

While investigating a lockup at startup on Powerbook 3400C, it was
identified that the fbdev driver generates alignment exception at
startup:

  --- interrupt: 600 at memset+0x60/0xc0
  NIP:  c0021414 LR: c03fc49c CTR: 00007fff
  REGS: ca021c10 TRAP: 0600   Tainted: G        W          (5.14.2-pmac-00727-g12a41fa69492)
  MSR:  00009032 &lt;EE,ME,IR,DR,RI&gt;  CR: 44008442  XER: 20000100
  DAR: cab80020 DSISR: 00017c07
  GPR00: 00000007 ca021cd0 c14412e0 cab80000 00000000 00100000 cab8001c 00000004
  GPR08: 00100000 00007fff 00000000 00000000 84008442 00000000 c0006fb4 00000000
  GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00100000
  GPR24: 00000000 81800000 00000320 c15fa400 c14d1878 00000000 c14d1800 c094e19c
  NIP [c0021414] memset+0x60/0xc0
  LR [c03fc49c] chipsfb_pci_init+0x160/0x580
  --- interrupt: 600
  [ca021cd0] [c03fc46c] chipsfb_pci_init+0x130/0x580 (unreliable)
  [ca021d20] [c03a3a70] pci_device_probe+0xf8/0x1b8
  [ca021d50] [c043d584] really_probe.part.0+0xac/0x388
  [ca021d70] [c043d914] __driver_probe_device+0xb4/0x170
  [ca021d90] [c043da18] driver_probe_device+0x48/0x144
  [ca021dc0] [c043e318] __driver_attach+0x11c/0x1c4
  [ca021de0] [c043ad30] bus_for_each_dev+0x88/0xf0
  [ca021e10] [c043c724] bus_add_driver+0x190/0x22c
  [ca021e40] [c043ee94] driver_register+0x9c/0x170
  [ca021e60] [c0006c28] do_one_initcall+0x54/0x1ec
  [ca021ed0] [c08246e4] kernel_init_freeable+0x1c0/0x270
  [ca021f10] [c0006fdc] kernel_init+0x28/0x11c
  [ca021f30] [c0017148] ret_from_kernel_thread+0x14/0x1c
  Instruction dump:
  7d4601a4 39490777 7d4701a4 39490888 7d4801a4 39490999 7d4901a4 39290aaa
  7d2a01a4 4c00012c 4bfffe88 0fe00000 &lt;4bfffe80&gt; 9421fff0 38210010 48001970

This is due to 'dcbz' instruction being used on non-cached memory.
'dcbz' instruction is used by memset() to zeroize a complete
cacheline at once, and memset() is not expected to be used on non
cached memory.

When performing a 'sparse' check on fbdev driver, it also appears
that the use of memset() is unexpected:

  drivers/video/fbdev/chipsfb.c:334:17: warning: incorrect type in argument 1 (different address spaces)
  drivers/video/fbdev/chipsfb.c:334:17:    expected void *
  drivers/video/fbdev/chipsfb.c:334:17:    got char [noderef] __iomem *screen_base
  drivers/video/fbdev/chipsfb.c:334:15: warning: memset with byte count of 1048576

Use fb_memset() instead of memset(). fb_memset() is defined as
memset_io() for powerpc.

Fixes: 8c8709334cec ("[PATCH] ppc32: Remove CONFIG_PMAC_PBOOK")
Reported-by: Stan Johnson &lt;userm57@yahoo.com&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/884a54f1e5cb774c1d9b4db780209bee5d4f6718.1631712563.git.christophe.leroy@csgroup.eu
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 f2719b26ae27282c145202ffd656d5ff1fe737cc ]

While investigating a lockup at startup on Powerbook 3400C, it was
identified that the fbdev driver generates alignment exception at
startup:

  --- interrupt: 600 at memset+0x60/0xc0
  NIP:  c0021414 LR: c03fc49c CTR: 00007fff
  REGS: ca021c10 TRAP: 0600   Tainted: G        W          (5.14.2-pmac-00727-g12a41fa69492)
  MSR:  00009032 &lt;EE,ME,IR,DR,RI&gt;  CR: 44008442  XER: 20000100
  DAR: cab80020 DSISR: 00017c07
  GPR00: 00000007 ca021cd0 c14412e0 cab80000 00000000 00100000 cab8001c 00000004
  GPR08: 00100000 00007fff 00000000 00000000 84008442 00000000 c0006fb4 00000000
  GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00100000
  GPR24: 00000000 81800000 00000320 c15fa400 c14d1878 00000000 c14d1800 c094e19c
  NIP [c0021414] memset+0x60/0xc0
  LR [c03fc49c] chipsfb_pci_init+0x160/0x580
  --- interrupt: 600
  [ca021cd0] [c03fc46c] chipsfb_pci_init+0x130/0x580 (unreliable)
  [ca021d20] [c03a3a70] pci_device_probe+0xf8/0x1b8
  [ca021d50] [c043d584] really_probe.part.0+0xac/0x388
  [ca021d70] [c043d914] __driver_probe_device+0xb4/0x170
  [ca021d90] [c043da18] driver_probe_device+0x48/0x144
  [ca021dc0] [c043e318] __driver_attach+0x11c/0x1c4
  [ca021de0] [c043ad30] bus_for_each_dev+0x88/0xf0
  [ca021e10] [c043c724] bus_add_driver+0x190/0x22c
  [ca021e40] [c043ee94] driver_register+0x9c/0x170
  [ca021e60] [c0006c28] do_one_initcall+0x54/0x1ec
  [ca021ed0] [c08246e4] kernel_init_freeable+0x1c0/0x270
  [ca021f10] [c0006fdc] kernel_init+0x28/0x11c
  [ca021f30] [c0017148] ret_from_kernel_thread+0x14/0x1c
  Instruction dump:
  7d4601a4 39490777 7d4701a4 39490888 7d4801a4 39490999 7d4901a4 39290aaa
  7d2a01a4 4c00012c 4bfffe88 0fe00000 &lt;4bfffe80&gt; 9421fff0 38210010 48001970

This is due to 'dcbz' instruction being used on non-cached memory.
'dcbz' instruction is used by memset() to zeroize a complete
cacheline at once, and memset() is not expected to be used on non
cached memory.

When performing a 'sparse' check on fbdev driver, it also appears
that the use of memset() is unexpected:

  drivers/video/fbdev/chipsfb.c:334:17: warning: incorrect type in argument 1 (different address spaces)
  drivers/video/fbdev/chipsfb.c:334:17:    expected void *
  drivers/video/fbdev/chipsfb.c:334:17:    got char [noderef] __iomem *screen_base
  drivers/video/fbdev/chipsfb.c:334:15: warning: memset with byte count of 1048576

Use fb_memset() instead of memset(). fb_memset() is defined as
memset_io() for powerpc.

Fixes: 8c8709334cec ("[PATCH] ppc32: Remove CONFIG_PMAC_PBOOK")
Reported-by: Stan Johnson &lt;userm57@yahoo.com&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/884a54f1e5cb774c1d9b4db780209bee5d4f6718.1631712563.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: fbdev: gbefb: Only instantiate device when built for IP32</title>
<updated>2021-10-13T08:08:19+00:00</updated>
<author>
<name>Mark Brown</name>
<email>broonie@kernel.org</email>
</author>
<published>2021-09-21T21:21:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cb7e651879839eae28a373b49a1e06b432c82a62'/>
<id>cb7e651879839eae28a373b49a1e06b432c82a62</id>
<content type='text'>
[ Upstream commit 11b8e2bb986d23157e82e267fb8cc6b281dfdee9 ]

The gbefb driver not only registers a driver but also the device for that
driver. This is all well and good when run on the IP32 machines that are
supported by the driver but since the driver supports building with
COMPILE_TEST we might also be building on other platforms which do not have
this hardware and will crash instantiating the driver. Add an IS_ENABLED()
check so we compile out the device registration if we don't have the Kconfig
option for the machine enabled.

Fixes: 552ccf6b259d290c0c ("video: fbdev: gbefb: add COMPILE_TEST support")
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Cc: Bartlomiej Zolnierkiewicz &lt;b.zolnierkie@samsung.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20210921212102.30803-1-broonie@kernel.org
Signed-off-by: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&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 11b8e2bb986d23157e82e267fb8cc6b281dfdee9 ]

The gbefb driver not only registers a driver but also the device for that
driver. This is all well and good when run on the IP32 machines that are
supported by the driver but since the driver supports building with
COMPILE_TEST we might also be building on other platforms which do not have
this hardware and will crash instantiating the driver. Add an IS_ENABLED()
check so we compile out the device registration if we don't have the Kconfig
option for the machine enabled.

Fixes: 552ccf6b259d290c0c ("video: fbdev: gbefb: add COMPILE_TEST support")
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Cc: Bartlomiej Zolnierkiewicz &lt;b.zolnierkie@samsung.com&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20210921212102.30803-1-broonie@kernel.org
Signed-off-by: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: fbdev: riva: Error out if 'pixclock' equals zero</title>
<updated>2021-09-22T10:26:29+00:00</updated>
<author>
<name>Zheyu Ma</name>
<email>zheyuma97@gmail.com</email>
</author>
<published>2021-07-26T10:03:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=faf0749c9062469631c26bbdc9d1d568d1241224'/>
<id>faf0749c9062469631c26bbdc9d1d568d1241224</id>
<content type='text'>
[ Upstream commit f92763cb0feba247e0939ed137b495601fd072a5 ]

The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of 'pixclock',
it may cause divide error.

Fix this by checking whether 'pixclock' is zero first.

The following log reveals it:

[   33.396850] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[   33.396864] CPU: 5 PID: 11754 Comm: i740 Not tainted 5.14.0-rc2-00513-gac532c9bbcfb-dirty #222
[   33.396883] RIP: 0010:riva_load_video_mode+0x417/0xf70
[   33.396969] Call Trace:
[   33.396973]  ? debug_smp_processor_id+0x1c/0x20
[   33.396984]  ? tick_nohz_tick_stopped+0x1a/0x90
[   33.396996]  ? rivafb_copyarea+0x3c0/0x3c0
[   33.397003]  ? wake_up_klogd.part.0+0x99/0xd0
[   33.397014]  ? vprintk_emit+0x110/0x4b0
[   33.397024]  ? vprintk_default+0x26/0x30
[   33.397033]  ? vprintk+0x9c/0x1f0
[   33.397041]  ? printk+0xba/0xed
[   33.397054]  ? record_print_text.cold+0x16/0x16
[   33.397063]  ? __kasan_check_read+0x11/0x20
[   33.397074]  ? profile_tick+0xc0/0x100
[   33.397084]  ? __sanitizer_cov_trace_const_cmp4+0x24/0x80
[   33.397094]  ? riva_set_rop_solid+0x2a0/0x2a0
[   33.397102]  rivafb_set_par+0xbe/0x610
[   33.397111]  ? riva_set_rop_solid+0x2a0/0x2a0
[   33.397119]  fb_set_var+0x5bf/0xeb0
[   33.397127]  ? fb_blank+0x1a0/0x1a0
[   33.397134]  ? lock_acquire+0x1ef/0x530
[   33.397143]  ? lock_release+0x810/0x810
[   33.397151]  ? lock_is_held_type+0x100/0x140
[   33.397159]  ? ___might_sleep+0x1ee/0x2d0
[   33.397170]  ? __mutex_lock+0x620/0x1190
[   33.397180]  ? trace_hardirqs_on+0x6a/0x1c0
[   33.397190]  do_fb_ioctl+0x31e/0x700

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-4-git-send-email-zheyuma97@gmail.com
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 f92763cb0feba247e0939ed137b495601fd072a5 ]

The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of 'pixclock',
it may cause divide error.

Fix this by checking whether 'pixclock' is zero first.

The following log reveals it:

[   33.396850] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[   33.396864] CPU: 5 PID: 11754 Comm: i740 Not tainted 5.14.0-rc2-00513-gac532c9bbcfb-dirty #222
[   33.396883] RIP: 0010:riva_load_video_mode+0x417/0xf70
[   33.396969] Call Trace:
[   33.396973]  ? debug_smp_processor_id+0x1c/0x20
[   33.396984]  ? tick_nohz_tick_stopped+0x1a/0x90
[   33.396996]  ? rivafb_copyarea+0x3c0/0x3c0
[   33.397003]  ? wake_up_klogd.part.0+0x99/0xd0
[   33.397014]  ? vprintk_emit+0x110/0x4b0
[   33.397024]  ? vprintk_default+0x26/0x30
[   33.397033]  ? vprintk+0x9c/0x1f0
[   33.397041]  ? printk+0xba/0xed
[   33.397054]  ? record_print_text.cold+0x16/0x16
[   33.397063]  ? __kasan_check_read+0x11/0x20
[   33.397074]  ? profile_tick+0xc0/0x100
[   33.397084]  ? __sanitizer_cov_trace_const_cmp4+0x24/0x80
[   33.397094]  ? riva_set_rop_solid+0x2a0/0x2a0
[   33.397102]  rivafb_set_par+0xbe/0x610
[   33.397111]  ? riva_set_rop_solid+0x2a0/0x2a0
[   33.397119]  fb_set_var+0x5bf/0xeb0
[   33.397127]  ? fb_blank+0x1a0/0x1a0
[   33.397134]  ? lock_acquire+0x1ef/0x530
[   33.397143]  ? lock_release+0x810/0x810
[   33.397151]  ? lock_is_held_type+0x100/0x140
[   33.397159]  ? ___might_sleep+0x1ee/0x2d0
[   33.397170]  ? __mutex_lock+0x620/0x1190
[   33.397180]  ? trace_hardirqs_on+0x6a/0x1c0
[   33.397190]  do_fb_ioctl+0x31e/0x700

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-4-git-send-email-zheyuma97@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: fbdev: kyro: Error out if 'pixclock' equals zero</title>
<updated>2021-09-22T10:26:29+00:00</updated>
<author>
<name>Zheyu Ma</name>
<email>zheyuma97@gmail.com</email>
</author>
<published>2021-07-26T10:03:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ae0d210aa717b480ca9f6337ec079f8c6913a04c'/>
<id>ae0d210aa717b480ca9f6337ec079f8c6913a04c</id>
<content type='text'>
[ Upstream commit 1520b4b7ba964f8eec2e7dd14c571d50de3e5191 ]

The userspace program could pass any values to the driver through
ioctl() interface. if the driver doesn't check the value of 'pixclock',
it may cause divide error because the value of 'lineclock' and
'frameclock' will be zero.

Fix this by checking whether 'pixclock' is zero in kyrofb_check_var().

The following log reveals it:

[  103.073930] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[  103.073942] CPU: 4 PID: 12483 Comm: syz-executor Not tainted 5.14.0-rc2-00478-g2734d6c1b1a0-dirty #118
[  103.073959] RIP: 0010:kyrofb_set_par+0x316/0xc80
[  103.074045] Call Trace:
[  103.074048]  ? ___might_sleep+0x1ee/0x2d0
[  103.074060]  ? kyrofb_ioctl+0x330/0x330
[  103.074069]  fb_set_var+0x5bf/0xeb0
[  103.074078]  ? fb_blank+0x1a0/0x1a0
[  103.074085]  ? lock_acquire+0x3bd/0x530
[  103.074094]  ? lock_release+0x810/0x810
[  103.074103]  ? ___might_sleep+0x1ee/0x2d0
[  103.074114]  ? __mutex_lock+0x620/0x1190
[  103.074126]  ? trace_hardirqs_on+0x6a/0x1c0
[  103.074137]  do_fb_ioctl+0x31e/0x700
[  103.074144]  ? fb_getput_cmap+0x280/0x280
[  103.074152]  ? rcu_read_lock_sched_held+0x11/0x80
[  103.074162]  ? rcu_read_lock_sched_held+0x11/0x80
[  103.074171]  ? __sanitizer_cov_trace_switch+0x67/0xf0
[  103.074181]  ? __sanitizer_cov_trace_const_cmp2+0x20/0x80
[  103.074191]  ? do_vfs_ioctl+0x14b/0x16c0
[  103.074199]  ? vfs_fileattr_set+0xb60/0xb60
[  103.074207]  ? rcu_read_lock_sched_held+0x11/0x80
[  103.074216]  ? lock_release+0x483/0x810
[  103.074224]  ? __fget_files+0x217/0x3d0
[  103.074234]  ? __fget_files+0x239/0x3d0
[  103.074243]  ? do_fb_ioctl+0x700/0x700
[  103.074250]  fb_ioctl+0xe6/0x130

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-3-git-send-email-zheyuma97@gmail.com
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 1520b4b7ba964f8eec2e7dd14c571d50de3e5191 ]

The userspace program could pass any values to the driver through
ioctl() interface. if the driver doesn't check the value of 'pixclock',
it may cause divide error because the value of 'lineclock' and
'frameclock' will be zero.

Fix this by checking whether 'pixclock' is zero in kyrofb_check_var().

The following log reveals it:

[  103.073930] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[  103.073942] CPU: 4 PID: 12483 Comm: syz-executor Not tainted 5.14.0-rc2-00478-g2734d6c1b1a0-dirty #118
[  103.073959] RIP: 0010:kyrofb_set_par+0x316/0xc80
[  103.074045] Call Trace:
[  103.074048]  ? ___might_sleep+0x1ee/0x2d0
[  103.074060]  ? kyrofb_ioctl+0x330/0x330
[  103.074069]  fb_set_var+0x5bf/0xeb0
[  103.074078]  ? fb_blank+0x1a0/0x1a0
[  103.074085]  ? lock_acquire+0x3bd/0x530
[  103.074094]  ? lock_release+0x810/0x810
[  103.074103]  ? ___might_sleep+0x1ee/0x2d0
[  103.074114]  ? __mutex_lock+0x620/0x1190
[  103.074126]  ? trace_hardirqs_on+0x6a/0x1c0
[  103.074137]  do_fb_ioctl+0x31e/0x700
[  103.074144]  ? fb_getput_cmap+0x280/0x280
[  103.074152]  ? rcu_read_lock_sched_held+0x11/0x80
[  103.074162]  ? rcu_read_lock_sched_held+0x11/0x80
[  103.074171]  ? __sanitizer_cov_trace_switch+0x67/0xf0
[  103.074181]  ? __sanitizer_cov_trace_const_cmp2+0x20/0x80
[  103.074191]  ? do_vfs_ioctl+0x14b/0x16c0
[  103.074199]  ? vfs_fileattr_set+0xb60/0xb60
[  103.074207]  ? rcu_read_lock_sched_held+0x11/0x80
[  103.074216]  ? lock_release+0x483/0x810
[  103.074224]  ? __fget_files+0x217/0x3d0
[  103.074234]  ? __fget_files+0x239/0x3d0
[  103.074243]  ? do_fb_ioctl+0x700/0x700
[  103.074250]  fb_ioctl+0xe6/0x130

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-3-git-send-email-zheyuma97@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: fbdev: asiliantfb: Error out if 'pixclock' equals zero</title>
<updated>2021-09-22T10:26:29+00:00</updated>
<author>
<name>Zheyu Ma</name>
<email>zheyuma97@gmail.com</email>
</author>
<published>2021-07-26T10:03:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=98551f0a7b57dd22d3349ec0424d566b2cd467c8'/>
<id>98551f0a7b57dd22d3349ec0424d566b2cd467c8</id>
<content type='text'>
[ Upstream commit b36b242d4b8ea178f7fd038965e3cac7f30c3f09 ]

The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of 'pixclock',
it may cause divide error.

Fix this by checking whether 'pixclock' is zero first.

The following log reveals it:

[   43.861711] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[   43.861737] CPU: 2 PID: 11764 Comm: i740 Not tainted 5.14.0-rc2-00513-gac532c9bbcfb-dirty #224
[   43.861756] RIP: 0010:asiliantfb_check_var+0x4e/0x730
[   43.861843] Call Trace:
[   43.861848]  ? asiliantfb_remove+0x190/0x190
[   43.861858]  fb_set_var+0x2e4/0xeb0
[   43.861866]  ? fb_blank+0x1a0/0x1a0
[   43.861873]  ? lock_acquire+0x1ef/0x530
[   43.861884]  ? lock_release+0x810/0x810
[   43.861892]  ? lock_is_held_type+0x100/0x140
[   43.861903]  ? ___might_sleep+0x1ee/0x2d0
[   43.861914]  ? __mutex_lock+0x620/0x1190
[   43.861921]  ? do_fb_ioctl+0x313/0x700
[   43.861929]  ? mutex_lock_io_nested+0xfa0/0xfa0
[   43.861936]  ? __this_cpu_preempt_check+0x1d/0x30
[   43.861944]  ? _raw_spin_unlock_irqrestore+0x46/0x60
[   43.861952]  ? lockdep_hardirqs_on+0x59/0x100
[   43.861959]  ? _raw_spin_unlock_irqrestore+0x46/0x60
[   43.861967]  ? trace_hardirqs_on+0x6a/0x1c0
[   43.861978]  do_fb_ioctl+0x31e/0x700

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-2-git-send-email-zheyuma97@gmail.com
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 b36b242d4b8ea178f7fd038965e3cac7f30c3f09 ]

The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of 'pixclock',
it may cause divide error.

Fix this by checking whether 'pixclock' is zero first.

The following log reveals it:

[   43.861711] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[   43.861737] CPU: 2 PID: 11764 Comm: i740 Not tainted 5.14.0-rc2-00513-gac532c9bbcfb-dirty #224
[   43.861756] RIP: 0010:asiliantfb_check_var+0x4e/0x730
[   43.861843] Call Trace:
[   43.861848]  ? asiliantfb_remove+0x190/0x190
[   43.861858]  fb_set_var+0x2e4/0xeb0
[   43.861866]  ? fb_blank+0x1a0/0x1a0
[   43.861873]  ? lock_acquire+0x1ef/0x530
[   43.861884]  ? lock_release+0x810/0x810
[   43.861892]  ? lock_is_held_type+0x100/0x140
[   43.861903]  ? ___might_sleep+0x1ee/0x2d0
[   43.861914]  ? __mutex_lock+0x620/0x1190
[   43.861921]  ? do_fb_ioctl+0x313/0x700
[   43.861929]  ? mutex_lock_io_nested+0xfa0/0xfa0
[   43.861936]  ? __this_cpu_preempt_check+0x1d/0x30
[   43.861944]  ? _raw_spin_unlock_irqrestore+0x46/0x60
[   43.861952]  ? lockdep_hardirqs_on+0x59/0x100
[   43.861959]  ? _raw_spin_unlock_irqrestore+0x46/0x60
[   43.861967]  ? trace_hardirqs_on+0x6a/0x1c0
[   43.861978]  do_fb_ioctl+0x31e/0x700

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-2-git-send-email-zheyuma97@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: fbdev: kyro: fix a DoS bug by restricting user input</title>
<updated>2021-09-22T10:26:27+00:00</updated>
<author>
<name>Zheyu Ma</name>
<email>zheyuma97@gmail.com</email>
</author>
<published>2021-07-14T04:09:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5adbbb27bb7ce6ad28d8f31232961630e4143811'/>
<id>5adbbb27bb7ce6ad28d8f31232961630e4143811</id>
<content type='text'>
[ Upstream commit 98a65439172dc69cb16834e62e852afc2adb83ed ]

The user can pass in any value to the driver through the 'ioctl'
interface. The driver dost not check, which may cause DoS bugs.

The following log reveals it:

divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:SetOverlayViewPort+0x133/0x5f0 drivers/video/fbdev/kyro/STG4000OverlayDevice.c:476
Call Trace:
 kyro_dev_overlay_viewport_set drivers/video/fbdev/kyro/fbdev.c:378 [inline]
 kyrofb_ioctl+0x2eb/0x330 drivers/video/fbdev/kyro/fbdev.c:603
 do_fb_ioctl+0x1f3/0x700 drivers/video/fbdev/core/fbmem.c:1171
 fb_ioctl+0xeb/0x130 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x19b/0x220 fs/ioctl.c:739
 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1626235762-2590-1-git-send-email-zheyuma97@gmail.com
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 98a65439172dc69cb16834e62e852afc2adb83ed ]

The user can pass in any value to the driver through the 'ioctl'
interface. The driver dost not check, which may cause DoS bugs.

The following log reveals it:

divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:SetOverlayViewPort+0x133/0x5f0 drivers/video/fbdev/kyro/STG4000OverlayDevice.c:476
Call Trace:
 kyro_dev_overlay_viewport_set drivers/video/fbdev/kyro/fbdev.c:378 [inline]
 kyrofb_ioctl+0x2eb/0x330 drivers/video/fbdev/kyro/fbdev.c:603
 do_fb_ioctl+0x1f3/0x700 drivers/video/fbdev/core/fbmem.c:1171
 fb_ioctl+0xeb/0x130 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x19b/0x220 fs/ioctl.c:739
 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/1626235762-2590-1-git-send-email-zheyuma97@gmail.com
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>2021-09-15T07:47:41+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=5de2ee621bc48fc527f0ed51265eea4bed8b769a'/>
<id>5de2ee621bc48fc527f0ed51265eea4bed8b769a</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: Do not delete the mode that is still in use</title>
<updated>2021-07-20T14:10:40+00:00</updated>
<author>
<name>Zhen Lei</name>
<email>thunder.leizhen@huawei.com</email>
</author>
<published>2021-07-12T08:55:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=359311b85ebec7c07c3a08ae2f3def946cad33fa'/>
<id>359311b85ebec7c07c3a08ae2f3def946cad33fa</id>
<content type='text'>
commit 0af778269a522c988ef0b4188556aba97fb420cc upstream.

The execution of fb_delete_videomode() is not based on the result of the
previous fbcon_mode_deleted(). As a result, the mode is directly deleted,
regardless of whether it is still in use, which may cause UAF.

==================================================================
BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \
drivers/video/fbdev/core/modedb.c:924
Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962

CPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ...
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x137/0x1be lib/dump_stack.c:118
 print_address_description+0x6c/0x640 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report+0x13d/0x1e0 mm/kasan/report.c:562
 fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924
 fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746
 fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975
 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 18960:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track+0x3d/0x70 mm/kasan/common.c:56
 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422
 slab_free_hook mm/slub.c:1541 [inline]
 slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574
 slab_free mm/slub.c:3139 [inline]
 kfree+0xca/0x3d0 mm/slub.c:4121
 fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104
 fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978
 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 13ff178ccd6d ("fbcon: Call fbcon_mode_deleted/new_modelist directly")
Signed-off-by: Zhen Lei &lt;thunder.leizhen@huawei.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v5.3+
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20210712085544.2828-1-thunder.leizhen@huawei.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 0af778269a522c988ef0b4188556aba97fb420cc upstream.

The execution of fb_delete_videomode() is not based on the result of the
previous fbcon_mode_deleted(). As a result, the mode is directly deleted,
regardless of whether it is still in use, which may cause UAF.

==================================================================
BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \
drivers/video/fbdev/core/modedb.c:924
Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962

CPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ...
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x137/0x1be lib/dump_stack.c:118
 print_address_description+0x6c/0x640 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report+0x13d/0x1e0 mm/kasan/report.c:562
 fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924
 fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746
 fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975
 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 18960:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track+0x3d/0x70 mm/kasan/common.c:56
 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422
 slab_free_hook mm/slub.c:1541 [inline]
 slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574
 slab_free mm/slub.c:3139 [inline]
 kfree+0xca/0x3d0 mm/slub.c:4121
 fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104
 fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978
 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 13ff178ccd6d ("fbcon: Call fbcon_mode_deleted/new_modelist directly")
Signed-off-by: Zhen Lei &lt;thunder.leizhen@huawei.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v5.3+
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20210712085544.2828-1-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: fbdev: imxfb: Fix an error message</title>
<updated>2021-07-14T14:53:26+00:00</updated>
<author>
<name>Christophe JAILLET</name>
<email>christophe.jaillet@wanadoo.fr</email>
</author>
<published>2021-05-06T18:57:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f9ad0b5ebacc24f382d8d9af86db99078fd8d96b'/>
<id>f9ad0b5ebacc24f382d8d9af86db99078fd8d96b</id>
<content type='text'>
[ Upstream commit 767d724a160eb1cd00c86fb8c2e21fa1ab3c37ac ]

'ret' is known to be 0 here.
No error code is available, so just remove it from the error message.

Fixes: 72330b0eeefc ("i.MX Framebuffer: Use readl/writel instead of direct pointer deref")
Reviewed-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/d7b25026f82659da3c6f7159eea480faa9d738be.1620327302.git.christophe.jaillet@wanadoo.fr
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 767d724a160eb1cd00c86fb8c2e21fa1ab3c37ac ]

'ret' is known to be 0 here.
No error code is available, so just remove it from the error message.

Fixes: 72330b0eeefc ("i.MX Framebuffer: Use readl/writel instead of direct pointer deref")
Reviewed-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/d7b25026f82659da3c6f7159eea480faa9d738be.1620327302.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: hgafb: correctly handle card detect failure during probe</title>
<updated>2021-05-26T10:05:21+00:00</updated>
<author>
<name>Anirudh Rayabharam</name>
<email>mail@anirudhrb.com</email>
</author>
<published>2021-05-16T19:27:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=46b4a9c68572f2c864dd204dbda6da34458c8b1a'/>
<id>46b4a9c68572f2c864dd204dbda6da34458c8b1a</id>
<content type='text'>
commit 02625c965239b71869326dd0461615f27307ecb3 upstream.

The return value of hga_card_detect() is not properly handled causing
the probe to succeed even though hga_card_detect() failed. Since probe
succeeds, hgafb_open() can be called which will end up operating on an
unmapped hga_vram. This results in an out-of-bounds access as reported
by kernel test robot [1].

To fix this, correctly detect failure of hga_card_detect() by checking
for a non-zero error code.

[1]: https://lore.kernel.org/lkml/20210516150019.GB25903@xsang-OptiPlex-9020/

Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference")
Cc: stable &lt;stable@vger.kernel.org&gt;
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Reviewed-by: Igor Matheus Andrade Torrente &lt;igormtorrente@gmail.com&gt;
Signed-off-by: Anirudh Rayabharam &lt;mail@anirudhrb.com&gt;
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Link: https://lore.kernel.org/r/20210516192714.25823-1-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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commit 02625c965239b71869326dd0461615f27307ecb3 upstream.

The return value of hga_card_detect() is not properly handled causing
the probe to succeed even though hga_card_detect() failed. Since probe
succeeds, hgafb_open() can be called which will end up operating on an
unmapped hga_vram. This results in an out-of-bounds access as reported
by kernel test robot [1].

To fix this, correctly detect failure of hga_card_detect() by checking
for a non-zero error code.

[1]: https://lore.kernel.org/lkml/20210516150019.GB25903@xsang-OptiPlex-9020/

Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference")
Cc: stable &lt;stable@vger.kernel.org&gt;
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Reviewed-by: Igor Matheus Andrade Torrente &lt;igormtorrente@gmail.com&gt;
Signed-off-by: Anirudh Rayabharam &lt;mail@anirudhrb.com&gt;
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Link: https://lore.kernel.org/r/20210516192714.25823-1-mail@anirudhrb.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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