<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers, branch v4.19.136</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>regmap: debugfs: check count when read regmap file</title>
<updated>2020-07-31T16:37:49+00:00</updated>
<author>
<name>Peng Fan</name>
<email>peng.fan@nxp.com</email>
</author>
<published>2020-03-13T01:58:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9989c022a11fd91f432d1311e5c2e7958c03d68f'/>
<id>9989c022a11fd91f432d1311e5c2e7958c03d68f</id>
<content type='text'>
commit 74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91 upstream.

When executing the following command, we met kernel dump.
dmesg -c &gt; /dev/null; cd /sys;
for i in `ls /sys/kernel/debug/regmap/* -d`; do
	echo "Checking regmap in $i";
	cat $i/registers;
done &amp;&amp; grep -ri "0x02d0" *;

It is because the count value is too big, and kmalloc fails. So add an
upper bound check to allow max size `PAGE_SIZE &lt;&lt; (MAX_ORDER - 1)`.

Signed-off-by: Peng Fan &lt;peng.fan@nxp.com&gt;
Link: https://lore.kernel.org/r/1584064687-12964-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Mark Brown &lt;broonie@kernel.org&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 74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91 upstream.

When executing the following command, we met kernel dump.
dmesg -c &gt; /dev/null; cd /sys;
for i in `ls /sys/kernel/debug/regmap/* -d`; do
	echo "Checking regmap in $i";
	cat $i/registers;
done &amp;&amp; grep -ri "0x02d0" *;

It is because the count value is too big, and kmalloc fails. So add an
upper bound check to allow max size `PAGE_SIZE &lt;&lt; (MAX_ORDER - 1)`.

Signed-off-by: Peng Fan &lt;peng.fan@nxp.com&gt;
Link: https://lore.kernel.org/r/1584064687-12964-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/net/wan/x25_asy: Fix to make it work</title>
<updated>2020-07-31T16:37:47+00:00</updated>
<author>
<name>Xie He</name>
<email>xie.he.0141@gmail.com</email>
</author>
<published>2020-07-16T23:44:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=745e883128cbe0d9a19955015ba96b57085eda09'/>
<id>745e883128cbe0d9a19955015ba96b57085eda09</id>
<content type='text'>
[ Upstream commit 8fdcabeac39824fe67480fd9508d80161c541854 ]

This driver is not working because of problems of its receiving code.
This patch fixes it to make it work.

When the driver receives an LAPB frame, it should first pass the frame
to the LAPB module to process. After processing, the LAPB module passes
the data (the packet) back to the driver, the driver should then add a
one-byte pseudo header and pass the data to upper layers.

The changes to the "x25_asy_bump" function and the
"x25_asy_data_indication" function are to correctly implement this
procedure.

Also, the "x25_asy_unesc" function ignores any frame that is shorter
than 3 bytes. However the shortest frames are 2-byte long. So we need
to change it to allow 2-byte frames to pass.

Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Martin Schiller &lt;ms@dev.tdt.de&gt;
Signed-off-by: Xie He &lt;xie.he.0141@gmail.com&gt;
Reviewed-by: Martin Schiller &lt;ms@dev.tdt.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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>
[ Upstream commit 8fdcabeac39824fe67480fd9508d80161c541854 ]

This driver is not working because of problems of its receiving code.
This patch fixes it to make it work.

When the driver receives an LAPB frame, it should first pass the frame
to the LAPB module to process. After processing, the LAPB module passes
the data (the packet) back to the driver, the driver should then add a
one-byte pseudo header and pass the data to upper layers.

The changes to the "x25_asy_bump" function and the
"x25_asy_data_indication" function are to correctly implement this
procedure.

Also, the "x25_asy_unesc" function ignores any frame that is shorter
than 3 bytes. However the shortest frames are 2-byte long. So we need
to change it to allow 2-byte frames to pass.

Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Martin Schiller &lt;ms@dev.tdt.de&gt;
Signed-off-by: Xie He &lt;xie.he.0141@gmail.com&gt;
Reviewed-by: Martin Schiller &lt;ms@dev.tdt.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ath9k: Fix regression with Atheros 9271</title>
<updated>2020-07-29T08:16:59+00:00</updated>
<author>
<name>Mark O'Donovan</name>
<email>shiftee@posteo.net</email>
</author>
<published>2020-07-11T04:33:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f3c154542ff7bda1ce2c398fce0181f9ab70a29b'/>
<id>f3c154542ff7bda1ce2c398fce0181f9ab70a29b</id>
<content type='text'>
commit 92f53e2fda8bb9a559ad61d57bfb397ce67ed0ab upstream.

This fix allows ath9k_htc modules to connect to WLAN once again.

Fixes: 2bbcaaee1fcb ("ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208251
Signed-off-by: Mark O'Donovan &lt;shiftee@posteo.net&gt;
Reported-by: Roman Mamedov &lt;rm@romanrm.net&gt;
Tested-by: Viktor Jägersküpper &lt;viktor_jaegerskuepper@freenet.de&gt;
Signed-off-by: Kalle Valo &lt;kvalo@codeaurora.org&gt;
Link: https://lore.kernel.org/r/20200711043324.8079-1-shiftee@posteo.net
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 92f53e2fda8bb9a559ad61d57bfb397ce67ed0ab upstream.

This fix allows ath9k_htc modules to connect to WLAN once again.

Fixes: 2bbcaaee1fcb ("ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208251
Signed-off-by: Mark O'Donovan &lt;shiftee@posteo.net&gt;
Reported-by: Roman Mamedov &lt;rm@romanrm.net&gt;
Tested-by: Viktor Jägersküpper &lt;viktor_jaegerskuepper@freenet.de&gt;
Signed-off-by: Kalle Valo &lt;kvalo@codeaurora.org&gt;
Link: https://lore.kernel.org/r/20200711043324.8079-1-shiftee@posteo.net
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb</title>
<updated>2020-07-29T08:16:59+00:00</updated>
<author>
<name>Qiujun Huang</name>
<email>hqjagain@gmail.com</email>
</author>
<published>2020-04-04T04:18:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=654ae85f1e1823688cda33cba130220d52a57989'/>
<id>654ae85f1e1823688cda33cba130220d52a57989</id>
<content type='text'>
commit 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05 upstream.

In ath9k_hif_usb_rx_cb interface number is assumed to be 0.
usb_ifnum_to_if(urb-&gt;dev, 0)
But it isn't always true.

The case reported by syzbot:
https://lore.kernel.org/linux-usb/000000000000666c9c05a1c05d12@google.com
usb 2-1: new high-speed USB device number 2 using dummy_hcd
usb 2-1: config 1 has an invalid interface number: 2 but max is 0
usb 2-1: config 1 has no interface number 0
usb 2-1: New USB device found, idVendor=0cf3, idProduct=9271, bcdDevice=
1.08
usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
general protection fault, probably for non-canonical address
0xdffffc0000000015: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af]
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc5-syzkaller #0

Call Trace
__usb_hcd_giveback_urb+0x29a/0x550 drivers/usb/core/hcd.c:1650
usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1716
dummy_timer+0x1258/0x32ae drivers/usb/gadget/udc/dummy_hcd.c:1966
call_timer_fn+0x195/0x6f0 kernel/time/timer.c:1404
expire_timers kernel/time/timer.c:1449 [inline]
__run_timers kernel/time/timer.c:1773 [inline]
__run_timers kernel/time/timer.c:1740 [inline]
run_timer_softirq+0x5f9/0x1500 kernel/time/timer.c:1786
__do_softirq+0x21e/0x950 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x178/0x1a0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:546 [inline]
smp_apic_timer_interrupt+0x141/0x540 arch/x86/kernel/apic/apic.c:1146
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829

Reported-and-tested-by: syzbot+40d5d2e8a4680952f042@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang &lt;hqjagain@gmail.com&gt;
Signed-off-by: Kalle Valo &lt;kvalo@codeaurora.org&gt;
Link: https://lore.kernel.org/r/20200404041838.10426-6-hqjagain@gmail.com
Cc: Viktor Jägersküpper &lt;viktor_jaegerskuepper@freenet.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 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05 upstream.

In ath9k_hif_usb_rx_cb interface number is assumed to be 0.
usb_ifnum_to_if(urb-&gt;dev, 0)
But it isn't always true.

The case reported by syzbot:
https://lore.kernel.org/linux-usb/000000000000666c9c05a1c05d12@google.com
usb 2-1: new high-speed USB device number 2 using dummy_hcd
usb 2-1: config 1 has an invalid interface number: 2 but max is 0
usb 2-1: config 1 has no interface number 0
usb 2-1: New USB device found, idVendor=0cf3, idProduct=9271, bcdDevice=
1.08
usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
general protection fault, probably for non-canonical address
0xdffffc0000000015: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af]
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc5-syzkaller #0

Call Trace
__usb_hcd_giveback_urb+0x29a/0x550 drivers/usb/core/hcd.c:1650
usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1716
dummy_timer+0x1258/0x32ae drivers/usb/gadget/udc/dummy_hcd.c:1966
call_timer_fn+0x195/0x6f0 kernel/time/timer.c:1404
expire_timers kernel/time/timer.c:1449 [inline]
__run_timers kernel/time/timer.c:1773 [inline]
__run_timers kernel/time/timer.c:1740 [inline]
run_timer_softirq+0x5f9/0x1500 kernel/time/timer.c:1786
__do_softirq+0x21e/0x950 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x178/0x1a0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:546 [inline]
smp_apic_timer_interrupt+0x141/0x540 arch/x86/kernel/apic/apic.c:1146
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829

Reported-and-tested-by: syzbot+40d5d2e8a4680952f042@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang &lt;hqjagain@gmail.com&gt;
Signed-off-by: Kalle Valo &lt;kvalo@codeaurora.org&gt;
Link: https://lore.kernel.org/r/20200404041838.10426-6-hqjagain@gmail.com
Cc: Viktor Jägersküpper &lt;viktor_jaegerskuepper@freenet.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>dm integrity: fix integrity recalculation that is improperly skipped</title>
<updated>2020-07-29T08:16:59+00:00</updated>
<author>
<name>Mikulas Patocka</name>
<email>mpatocka@redhat.com</email>
</author>
<published>2020-07-23T14:42:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cab7ef0066401efb5ab2dea1d85f490ce9c626f3'/>
<id>cab7ef0066401efb5ab2dea1d85f490ce9c626f3</id>
<content type='text'>
commit 5df96f2b9f58a5d2dc1f30fe7de75e197f2c25f2 upstream.

Commit adc0daad366b62ca1bce3e2958a40b0b71a8b8b3 ("dm: report suspended
device during destroy") broke integrity recalculation.

The problem is dm_suspended() returns true not only during suspend,
but also during resume. So this race condition could occur:
1. dm_integrity_resume calls queue_work(ic-&gt;recalc_wq, &amp;ic-&gt;recalc_work)
2. integrity_recalc (&amp;ic-&gt;recalc_work) preempts the current thread
3. integrity_recalc calls if (unlikely(dm_suspended(ic-&gt;ti))) goto unlock_ret;
4. integrity_recalc exits and no recalculating is done.

To fix this race condition, add a function dm_post_suspending that is
only true during the postsuspend phase and use it instead of
dm_suspended().

Signed-off-by: Mikulas Patocka &lt;mpatocka redhat com&gt;
Fixes: adc0daad366b ("dm: report suspended device during destroy")
Cc: stable vger kernel org # v4.18+
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&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 5df96f2b9f58a5d2dc1f30fe7de75e197f2c25f2 upstream.

Commit adc0daad366b62ca1bce3e2958a40b0b71a8b8b3 ("dm: report suspended
device during destroy") broke integrity recalculation.

The problem is dm_suspended() returns true not only during suspend,
but also during resume. So this race condition could occur:
1. dm_integrity_resume calls queue_work(ic-&gt;recalc_wq, &amp;ic-&gt;recalc_work)
2. integrity_recalc (&amp;ic-&gt;recalc_work) preempts the current thread
3. integrity_recalc calls if (unlikely(dm_suspended(ic-&gt;ti))) goto unlock_ret;
4. integrity_recalc exits and no recalculating is done.

To fix this race condition, add a function dm_post_suspending that is
only true during the postsuspend phase and use it instead of
dm_suspended().

Signed-off-by: Mikulas Patocka &lt;mpatocka redhat com&gt;
Fixes: adc0daad366b ("dm: report suspended device during destroy")
Cc: stable vger kernel org # v4.18+
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amd/powerplay: fix a crash when overclocking Vega M</title>
<updated>2020-07-29T08:16:58+00:00</updated>
<author>
<name>Qiu Wenbo</name>
<email>qiuwenbo@phytium.com.cn</email>
</author>
<published>2020-07-17T07:09:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c24131ef099a065e4b9263440b03031b9328809c'/>
<id>c24131ef099a065e4b9263440b03031b9328809c</id>
<content type='text'>
commit 88bb16ad998a0395fe4b346b7d3f621aaa0a2324 upstream.

Avoid kernel crash when vddci_control is SMU7_VOLTAGE_CONTROL_NONE and
vddci_voltage_table is empty. It has been tested on Intel Hades Canyon
(i7-8809G).

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=208489
Fixes: ac7822b0026f ("drm/amd/powerplay: add smumgr support for VEGAM (v2)")
Reviewed-by: Evan Quan &lt;evan.quan@amd.com&gt;
Signed-off-by: Qiu Wenbo &lt;qiuwenbo@phytium.com.cn&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: stable@vger.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 88bb16ad998a0395fe4b346b7d3f621aaa0a2324 upstream.

Avoid kernel crash when vddci_control is SMU7_VOLTAGE_CONTROL_NONE and
vddci_voltage_table is empty. It has been tested on Intel Hades Canyon
(i7-8809G).

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=208489
Fixes: ac7822b0026f ("drm/amd/powerplay: add smumgr support for VEGAM (v2)")
Reviewed-by: Evan Quan &lt;evan.quan@amd.com&gt;
Signed-off-by: Qiu Wenbo &lt;qiuwenbo@phytium.com.cn&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: Fix NULL dereference in dpm sysfs handlers</title>
<updated>2020-07-29T08:16:58+00:00</updated>
<author>
<name>Paweł Gronowski</name>
<email>me@woland.xyz</email>
</author>
<published>2020-07-19T15:54:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9468cf97910aea551c0d8f423cc30a13bda7490e'/>
<id>9468cf97910aea551c0d8f423cc30a13bda7490e</id>
<content type='text'>
commit 38e0c89a19fd13f28d2b4721035160a3e66e270b upstream.

NULL dereference occurs when string that is not ended with space or
newline is written to some dpm sysfs interface (for example pp_dpm_sclk).
This happens because strsep replaces the tmp with NULL if the delimiter
is not present in string, which is then dereferenced by tmp[0].

Reproduction example:
sudo sh -c 'echo -n 1 &gt; /sys/class/drm/card0/device/pp_dpm_sclk'

Signed-off-by: Paweł Gronowski &lt;me@woland.xyz&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: stable@vger.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 38e0c89a19fd13f28d2b4721035160a3e66e270b upstream.

NULL dereference occurs when string that is not ended with space or
newline is written to some dpm sysfs interface (for example pp_dpm_sclk).
This happens because strsep replaces the tmp with NULL if the delimiter
is not present in string, which is then dereferenced by tmp[0].

Reproduction example:
sudo sh -c 'echo -n 1 &gt; /sys/class/drm/card0/device/pp_dpm_sclk'

Signed-off-by: Paweł Gronowski &lt;me@woland.xyz&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vt: Reject zero-sized screen buffer size.</title>
<updated>2020-07-29T08:16:56+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2020-07-12T11:10:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=74752b81eae8ae64e97de222320026367e92c4b5'/>
<id>74752b81eae8ae64e97de222320026367e92c4b5</id>
<content type='text'>
commit ce684552a266cb1c7cc2f7e623f38567adec6653 upstream.

syzbot is reporting general protection fault in do_con_write() [1] caused
by vc-&gt;vc_screenbuf == ZERO_SIZE_PTR caused by vc-&gt;vc_screenbuf_size == 0
caused by vc-&gt;vc_cols == vc-&gt;vc_rows == vc-&gt;vc_size_row == 0 caused by
fb_set_var() from ioctl(FBIOPUT_VSCREENINFO) on /dev/fb0 , for
gotoxy(vc, 0, 0) from reset_terminal() from vc_init() from vc_allocate()
 from con_install() from tty_init_dev() from tty_open() on such console
causes vc-&gt;vc_pos == 0x10000000e due to
((unsigned long) ZERO_SIZE_PTR) + -1U * 0 + (-1U &lt;&lt; 1).

I don't think that a console with 0 column or 0 row makes sense. And it
seems that vc_do_resize() does not intend to allow resizing a console to
0 column or 0 row due to

  new_cols = (cols ? cols : vc-&gt;vc_cols);
  new_rows = (lines ? lines : vc-&gt;vc_rows);

exception.

Theoretically, cols and rows can be any range as long as
0 &lt; cols * rows * 2 &lt;= KMALLOC_MAX_SIZE is satisfied (e.g.
cols == 1048576 &amp;&amp; rows == 2 is possible) because of

  vc-&gt;vc_size_row = vc-&gt;vc_cols &lt;&lt; 1;
  vc-&gt;vc_screenbuf_size = vc-&gt;vc_rows * vc-&gt;vc_size_row;

in visual_init() and kzalloc(vc-&gt;vc_screenbuf_size) in vc_allocate().

Since we can detect cols == 0 or rows == 0 via screenbuf_size = 0 in
visual_init(), we can reject kzalloc(0). Then, vc_allocate() will return
an error, and con_write() will not be called on a console with 0 column
or 0 row.

We need to make sure that integer overflow in visual_init() won't happen.
Since vc_do_resize() restricts cols &lt;= 32767 and rows &lt;= 32767, applying
1 &lt;= cols &lt;= 32767 and 1 &lt;= rows &lt;= 32767 restrictions to vc_allocate()
will be practically fine.

This patch does not touch con_init(), for returning -EINVAL there
does not help when we are not returning -ENOMEM.

[1] https://syzkaller.appspot.com/bug?extid=017265e8553724e514e8

Reported-and-tested-by: syzbot &lt;syzbot+017265e8553724e514e8@syzkaller.appspotmail.com&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20200712111013.11881-1-penguin-kernel@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 ce684552a266cb1c7cc2f7e623f38567adec6653 upstream.

syzbot is reporting general protection fault in do_con_write() [1] caused
by vc-&gt;vc_screenbuf == ZERO_SIZE_PTR caused by vc-&gt;vc_screenbuf_size == 0
caused by vc-&gt;vc_cols == vc-&gt;vc_rows == vc-&gt;vc_size_row == 0 caused by
fb_set_var() from ioctl(FBIOPUT_VSCREENINFO) on /dev/fb0 , for
gotoxy(vc, 0, 0) from reset_terminal() from vc_init() from vc_allocate()
 from con_install() from tty_init_dev() from tty_open() on such console
causes vc-&gt;vc_pos == 0x10000000e due to
((unsigned long) ZERO_SIZE_PTR) + -1U * 0 + (-1U &lt;&lt; 1).

I don't think that a console with 0 column or 0 row makes sense. And it
seems that vc_do_resize() does not intend to allow resizing a console to
0 column or 0 row due to

  new_cols = (cols ? cols : vc-&gt;vc_cols);
  new_rows = (lines ? lines : vc-&gt;vc_rows);

exception.

Theoretically, cols and rows can be any range as long as
0 &lt; cols * rows * 2 &lt;= KMALLOC_MAX_SIZE is satisfied (e.g.
cols == 1048576 &amp;&amp; rows == 2 is possible) because of

  vc-&gt;vc_size_row = vc-&gt;vc_cols &lt;&lt; 1;
  vc-&gt;vc_screenbuf_size = vc-&gt;vc_rows * vc-&gt;vc_size_row;

in visual_init() and kzalloc(vc-&gt;vc_screenbuf_size) in vc_allocate().

Since we can detect cols == 0 or rows == 0 via screenbuf_size = 0 in
visual_init(), we can reject kzalloc(0). Then, vc_allocate() will return
an error, and con_write() will not be called on a console with 0 column
or 0 row.

We need to make sure that integer overflow in visual_init() won't happen.
Since vc_do_resize() restricts cols &lt;= 32767 and rows &lt;= 32767, applying
1 &lt;= cols &lt;= 32767 and 1 &lt;= rows &lt;= 32767 restrictions to vc_allocate()
will be practically fine.

This patch does not touch con_init(), for returning -EINVAL there
does not help when we are not returning -ENOMEM.

[1] https://syzkaller.appspot.com/bug?extid=017265e8553724e514e8

Reported-and-tested-by: syzbot &lt;syzbot+017265e8553724e514e8@syzkaller.appspotmail.com&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20200712111013.11881-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: Detect integer underflow at "struct fbcon_ops"-&gt;clear_margins.</title>
<updated>2020-07-29T08:16:56+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2020-07-15T01:51:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dd58bd1b95b7127bb975942e14c4a9bd878c28db'/>
<id>dd58bd1b95b7127bb975942e14c4a9bd878c28db</id>
<content type='text'>
commit 033724d6864245a11f8e04c066002e6ad22b3fd0 upstream.

syzbot is reporting general protection fault in bitfill_aligned() [1]
caused by integer underflow in bit_clear_margins(). The cause of this
problem is when and how do_vc_resize() updates vc-&gt;vc_{cols,rows}.

If vc_do_resize() fails (e.g. kzalloc() fails) when var.xres or var.yres
is going to shrink, vc-&gt;vc_{cols,rows} will not be updated. This allows
bit_clear_margins() to see info-&gt;var.xres &lt; (vc-&gt;vc_cols * cw) or
info-&gt;var.yres &lt; (vc-&gt;vc_rows * ch). Unexpectedly large rw or bh will
try to overrun the __iomem region and causes general protection fault.

Also, vc_resize(vc, 0, 0) does not set vc-&gt;vc_{cols,rows} = 0 due to

  new_cols = (cols ? cols : vc-&gt;vc_cols);
  new_rows = (lines ? lines : vc-&gt;vc_rows);

exception. Since cols and lines are calculated as

  cols = FBCON_SWAP(ops-&gt;rotate, info-&gt;var.xres, info-&gt;var.yres);
  rows = FBCON_SWAP(ops-&gt;rotate, info-&gt;var.yres, info-&gt;var.xres);
  cols /= vc-&gt;vc_font.width;
  rows /= vc-&gt;vc_font.height;
  vc_resize(vc, cols, rows);

in fbcon_modechanged(), var.xres &lt; vc-&gt;vc_font.width makes cols = 0
and var.yres &lt; vc-&gt;vc_font.height makes rows = 0. This means that

  const int fd = open("/dev/fb0", O_ACCMODE);
  struct fb_var_screeninfo var = { };
  ioctl(fd, FBIOGET_VSCREENINFO, &amp;var);
  var.xres = var.yres = 1;
  ioctl(fd, FBIOPUT_VSCREENINFO, &amp;var);

easily reproduces integer underflow bug explained above.

Of course, callers of vc_resize() are not handling vc_do_resize() failure
is bad. But we can't avoid vc_resize(vc, 0, 0) which returns 0. Therefore,
as a band-aid workaround, this patch checks integer underflow in
"struct fbcon_ops"-&gt;clear_margins call, assuming that
vc-&gt;vc_cols * vc-&gt;vc_font.width and vc-&gt;vc_rows * vc-&gt;vc_font.heigh do not
cause integer overflow.

[1] https://syzkaller.appspot.com/bug?id=a565882df74fa76f10d3a6fec4be31098dbb37c6

Reported-and-tested-by: syzbot &lt;syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Acked-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20200715015102.3814-1-penguin-kernel@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 033724d6864245a11f8e04c066002e6ad22b3fd0 upstream.

syzbot is reporting general protection fault in bitfill_aligned() [1]
caused by integer underflow in bit_clear_margins(). The cause of this
problem is when and how do_vc_resize() updates vc-&gt;vc_{cols,rows}.

If vc_do_resize() fails (e.g. kzalloc() fails) when var.xres or var.yres
is going to shrink, vc-&gt;vc_{cols,rows} will not be updated. This allows
bit_clear_margins() to see info-&gt;var.xres &lt; (vc-&gt;vc_cols * cw) or
info-&gt;var.yres &lt; (vc-&gt;vc_rows * ch). Unexpectedly large rw or bh will
try to overrun the __iomem region and causes general protection fault.

Also, vc_resize(vc, 0, 0) does not set vc-&gt;vc_{cols,rows} = 0 due to

  new_cols = (cols ? cols : vc-&gt;vc_cols);
  new_rows = (lines ? lines : vc-&gt;vc_rows);

exception. Since cols and lines are calculated as

  cols = FBCON_SWAP(ops-&gt;rotate, info-&gt;var.xres, info-&gt;var.yres);
  rows = FBCON_SWAP(ops-&gt;rotate, info-&gt;var.yres, info-&gt;var.xres);
  cols /= vc-&gt;vc_font.width;
  rows /= vc-&gt;vc_font.height;
  vc_resize(vc, cols, rows);

in fbcon_modechanged(), var.xres &lt; vc-&gt;vc_font.width makes cols = 0
and var.yres &lt; vc-&gt;vc_font.height makes rows = 0. This means that

  const int fd = open("/dev/fb0", O_ACCMODE);
  struct fb_var_screeninfo var = { };
  ioctl(fd, FBIOGET_VSCREENINFO, &amp;var);
  var.xres = var.yres = 1;
  ioctl(fd, FBIOPUT_VSCREENINFO, &amp;var);

easily reproduces integer underflow bug explained above.

Of course, callers of vc_resize() are not handling vc_do_resize() failure
is bad. But we can't avoid vc_resize(vc, 0, 0) which returns 0. Therefore,
as a band-aid workaround, this patch checks integer underflow in
"struct fbcon_ops"-&gt;clear_margins call, assuming that
vc-&gt;vc_cols * vc-&gt;vc_font.width and vc-&gt;vc_rows * vc-&gt;vc_font.heigh do not
cause integer overflow.

[1] https://syzkaller.appspot.com/bug?id=a565882df74fa76f10d3a6fec4be31098dbb37c6

Reported-and-tested-by: syzbot &lt;syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Acked-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20200715015102.3814-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>serial: 8250_mtk: Fix high-speed baud rates clamping</title>
<updated>2020-07-29T08:16:56+00:00</updated>
<author>
<name>Serge Semin</name>
<email>Sergey.Semin@baikalelectronics.ru</email>
</author>
<published>2020-07-14T12:41:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5ccfaf3878968fbf40134ab5c6e3f3addd24ceb8'/>
<id>5ccfaf3878968fbf40134ab5c6e3f3addd24ceb8</id>
<content type='text'>
commit 551e553f0d4ab623e2a6f424ab5834f9c7b5229c upstream.

Commit 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250
port") fixed limits of a baud rate setting for a generic 8250 port.
In other words since that commit the baud rate has been permitted to be
within [uartclk / 16 / UART_DIV_MAX; uartclk / 16], which is absolutely
normal for a standard 8250 UART port. But there are custom 8250 ports,
which provide extended baud rate limits. In particular the Mediatek 8250
port can work with baud rates up to "uartclk" speed.

Normally that and any other peculiarity is supposed to be handled in a
custom set_termios() callback implemented in the vendor-specific
8250-port glue-driver. Currently that is how it's done for the most of
the vendor-specific 8250 ports, but for some reason for Mediatek a
solution has been spread out to both the glue-driver and to the generic
8250-port code. Due to that a bug has been introduced, which permitted the
extended baud rate limit for all even for standard 8250-ports. The bug
has been fixed by the commit 7b668c064ec3 ("serial: 8250: Fix max baud
limit in generic 8250 port") by narrowing the baud rates limit back down to
the normal bounds. Unfortunately by doing so we also broke the
Mediatek-specific extended bauds feature.

A fix of the problem described above is twofold. First since we can't get
back the extended baud rate limits feature to the generic set_termios()
function and that method supports only a standard baud rates range, the
requested baud rate must be locally stored before calling it and then
restored back to the new termios structure after the generic set_termios()
finished its magic business. By doing so we still use the
serial8250_do_set_termios() method to set the LCR/MCR/FCR/etc. registers,
while the extended baud rate setting procedure will be performed later in
the custom Mediatek-specific set_termios() callback. Second since a true
baud rate is now fully calculated in the custom set_termios() method we
need to locally update the port timeout by calling the
uart_update_timeout() function. After the fixes described above are
implemented in the 8250_mtk.c driver, the Mediatek 8250-port should
get back to normally working with extended baud rates.

Link: https://lore.kernel.org/linux-serial/20200701211337.3027448-1-danielwinkler@google.com

Fixes: 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250 port")
Reported-by: Daniel Winkler &lt;danielwinkler@google.com&gt;
Signed-off-by: Serge Semin &lt;Sergey.Semin@baikalelectronics.ru&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Tested-by: Claire Chang &lt;tientzu@chromium.org&gt;
Link: https://lore.kernel.org/r/20200714124113.20918-1-Sergey.Semin@baikalelectronics.ru
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 551e553f0d4ab623e2a6f424ab5834f9c7b5229c upstream.

Commit 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250
port") fixed limits of a baud rate setting for a generic 8250 port.
In other words since that commit the baud rate has been permitted to be
within [uartclk / 16 / UART_DIV_MAX; uartclk / 16], which is absolutely
normal for a standard 8250 UART port. But there are custom 8250 ports,
which provide extended baud rate limits. In particular the Mediatek 8250
port can work with baud rates up to "uartclk" speed.

Normally that and any other peculiarity is supposed to be handled in a
custom set_termios() callback implemented in the vendor-specific
8250-port glue-driver. Currently that is how it's done for the most of
the vendor-specific 8250 ports, but for some reason for Mediatek a
solution has been spread out to both the glue-driver and to the generic
8250-port code. Due to that a bug has been introduced, which permitted the
extended baud rate limit for all even for standard 8250-ports. The bug
has been fixed by the commit 7b668c064ec3 ("serial: 8250: Fix max baud
limit in generic 8250 port") by narrowing the baud rates limit back down to
the normal bounds. Unfortunately by doing so we also broke the
Mediatek-specific extended bauds feature.

A fix of the problem described above is twofold. First since we can't get
back the extended baud rate limits feature to the generic set_termios()
function and that method supports only a standard baud rates range, the
requested baud rate must be locally stored before calling it and then
restored back to the new termios structure after the generic set_termios()
finished its magic business. By doing so we still use the
serial8250_do_set_termios() method to set the LCR/MCR/FCR/etc. registers,
while the extended baud rate setting procedure will be performed later in
the custom Mediatek-specific set_termios() callback. Second since a true
baud rate is now fully calculated in the custom set_termios() method we
need to locally update the port timeout by calling the
uart_update_timeout() function. After the fixes described above are
implemented in the 8250_mtk.c driver, the Mediatek 8250-port should
get back to normally working with extended baud rates.

Link: https://lore.kernel.org/linux-serial/20200701211337.3027448-1-danielwinkler@google.com

Fixes: 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250 port")
Reported-by: Daniel Winkler &lt;danielwinkler@google.com&gt;
Signed-off-by: Serge Semin &lt;Sergey.Semin@baikalelectronics.ru&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Tested-by: Claire Chang &lt;tientzu@chromium.org&gt;
Link: https://lore.kernel.org/r/20200714124113.20918-1-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
