<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/net/usb, branch v6.6</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>r8152: Block future register access if register access fails</title>
<updated>2023-10-22T10:46:18+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2023-10-20T21:06:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d9962b0d42029bcb40fe3c38bce06d1870fa4df4'/>
<id>d9962b0d42029bcb40fe3c38bce06d1870fa4df4</id>
<content type='text'>
Even though the functions to read/write registers can fail, most of
the places in the r8152 driver that read/write register values don't
check error codes. The lack of error code checking is problematic in
at least two ways.

The first problem is that the r8152 driver often uses code patterns
similar to this:
  x = read_register()
  x = x | SOME_BIT;
  write_register(x);

...with the above pattern, if the read_register() fails and returns
garbage then we'll end up trying to write modified garbage back to the
Realtek adapter. If the write_register() succeeds that's bad. Note
that as of commit f53a7ad18959 ("r8152: Set memory to all 0xFFs on
failed reg reads") the "garbage" returned by read_register() will at
least be consistent garbage, but it is still garbage.

It turns out that this problem is very serious. Writing garbage to
some of the hardware registers on the Ethernet adapter can put the
adapter in such a bad state that it needs to be power cycled (fully
unplugged and plugged in again) before it can enumerate again.

The second problem is that the r8152 driver generally has functions
that are long sequences of register writes. Assuming everything will
be OK if a random register write fails in the middle isn't a great
assumption.

One might wonder if the above two problems are real. You could ask if
we would really have a successful write after a failed read. It turns
out that the answer appears to be "yes, this can happen". In fact,
we've seen at least two distinct failure modes where this happens.

On a sc7180-trogdor Chromebook if you drop into kdb for a while and
then resume, you can see:
1. We get a "Tx timeout"
2. The "Tx timeout" queues up a USB reset.
3. In rtl8152_pre_reset() we try to reinit the hardware.
4. The first several (2-9) register accesses fail with a timeout, then
   things recover.

The above test case was actually fixed by the patch ("r8152: Increase
USB control msg timeout to 5000ms as per spec") but at least shows
that we really can see successful calls after failed ones.

On a different (AMD) based Chromebook with a particular adapter, we
found that during reboot tests we'd also sometimes get a transitory
failure. In this case we saw -EPIPE being returned sometimes. Retrying
worked, but retrying is not always safe for all register accesses
since reading/writing some registers might have side effects (like
registers that clear on read).

Let's fully lock out all register access if a register access fails.
When we do this, we'll try to queue up a USB reset and try to unlock
register access after the reset. This is slightly tricker than it
sounds since the r8152 driver has an optimized reset sequence that
only works reliably after probe happens. In order to handle this, we
avoid the optimized reset if probe didn't finish. Instead, we simply
retry the probe routine in this case.

When locking out access, we'll use the existing infrastructure that
the driver was using when it detected we were unplugged. This keeps us
from getting stuck in delay loops in some parts of the driver.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Even though the functions to read/write registers can fail, most of
the places in the r8152 driver that read/write register values don't
check error codes. The lack of error code checking is problematic in
at least two ways.

The first problem is that the r8152 driver often uses code patterns
similar to this:
  x = read_register()
  x = x | SOME_BIT;
  write_register(x);

...with the above pattern, if the read_register() fails and returns
garbage then we'll end up trying to write modified garbage back to the
Realtek adapter. If the write_register() succeeds that's bad. Note
that as of commit f53a7ad18959 ("r8152: Set memory to all 0xFFs on
failed reg reads") the "garbage" returned by read_register() will at
least be consistent garbage, but it is still garbage.

It turns out that this problem is very serious. Writing garbage to
some of the hardware registers on the Ethernet adapter can put the
adapter in such a bad state that it needs to be power cycled (fully
unplugged and plugged in again) before it can enumerate again.

The second problem is that the r8152 driver generally has functions
that are long sequences of register writes. Assuming everything will
be OK if a random register write fails in the middle isn't a great
assumption.

One might wonder if the above two problems are real. You could ask if
we would really have a successful write after a failed read. It turns
out that the answer appears to be "yes, this can happen". In fact,
we've seen at least two distinct failure modes where this happens.

On a sc7180-trogdor Chromebook if you drop into kdb for a while and
then resume, you can see:
1. We get a "Tx timeout"
2. The "Tx timeout" queues up a USB reset.
3. In rtl8152_pre_reset() we try to reinit the hardware.
4. The first several (2-9) register accesses fail with a timeout, then
   things recover.

The above test case was actually fixed by the patch ("r8152: Increase
USB control msg timeout to 5000ms as per spec") but at least shows
that we really can see successful calls after failed ones.

On a different (AMD) based Chromebook with a particular adapter, we
found that during reboot tests we'd also sometimes get a transitory
failure. In this case we saw -EPIPE being returned sometimes. Retrying
worked, but retrying is not always safe for all register accesses
since reading/writing some registers might have side effects (like
registers that clear on read).

Let's fully lock out all register access if a register access fails.
When we do this, we'll try to queue up a USB reset and try to unlock
register access after the reset. This is slightly tricker than it
sounds since the r8152 driver has an optimized reset sequence that
only works reliably after probe happens. In order to handle this, we
avoid the optimized reset if probe didn't finish. Instead, we simply
retry the probe routine in this case.

When locking out access, we'll use the existing infrastructure that
the driver was using when it detected we were unplugged. This keeps us
from getting stuck in delay loops in some parts of the driver.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>r8152: Rename RTL8152_UNPLUG to RTL8152_INACCESSIBLE</title>
<updated>2023-10-22T10:46:18+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2023-10-20T21:06:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=715f67f33af45ce2cc3a5b1ef133cc8c8e7787b0'/>
<id>715f67f33af45ce2cc3a5b1ef133cc8c8e7787b0</id>
<content type='text'>
Whenever the RTL8152_UNPLUG is set that just tells the driver that all
accesses will fail and we should just immediately bail. A future patch
will use this same concept at a time when the driver hasn't actually
been unplugged but is about to be reset. Rename the flag in
preparation for the future patch.

This is a no-op change and just a search and replace.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Whenever the RTL8152_UNPLUG is set that just tells the driver that all
accesses will fail and we should just immediately bail. A future patch
will use this same concept at a time when the driver hasn't actually
been unplugged but is about to be reset. Rename the flag in
preparation for the future patch.

This is a no-op change and just a search and replace.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>r8152: Check for unplug in r8153b_ups_en() / r8153c_ups_en()</title>
<updated>2023-10-22T10:46:18+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2023-10-20T21:06:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bc65cc42af737a5a35f83842408ef2c6c79ba025'/>
<id>bc65cc42af737a5a35f83842408ef2c6c79ba025</id>
<content type='text'>
If the adapter is unplugged while we're looping in r8153b_ups_en() /
r8153c_ups_en() we could end up looping for 10 seconds (20 ms * 500
loops). Add code similar to what's done in other places in the driver
to check for unplug and bail.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the adapter is unplugged while we're looping in r8153b_ups_en() /
r8153c_ups_en() we could end up looping for 10 seconds (20 ms * 500
loops). Add code similar to what's done in other places in the driver
to check for unplug and bail.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>r8152: Check for unplug in rtl_phy_patch_request()</title>
<updated>2023-10-22T10:46:18+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2023-10-20T21:06:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dc90ba37a8c37042407fa6970b9830890cfe6047'/>
<id>dc90ba37a8c37042407fa6970b9830890cfe6047</id>
<content type='text'>
If the adapter is unplugged while we're looping in
rtl_phy_patch_request() we could end up looping for 10 seconds (2 ms *
5000 loops). Add code similar to what's done in other places in the
driver to check for unplug and bail.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the adapter is unplugged while we're looping in
rtl_phy_patch_request() we could end up looping for 10 seconds (2 ms *
5000 loops). Add code similar to what's done in other places in the
driver to check for unplug and bail.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>r8152: Release firmware if we have an error in probe</title>
<updated>2023-10-22T10:46:18+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2023-10-20T21:06:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b8d35024d4059ca550cba11ac9ab23a6c238d929'/>
<id>b8d35024d4059ca550cba11ac9ab23a6c238d929</id>
<content type='text'>
The error handling in rtl8152_probe() is missing a call to release
firmware. Add it in to match what's in the cleanup code in
rtl8152_disconnect().

Fixes: 9370f2d05a2a ("r8152: support request_firmware for RTL8153")
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The error handling in rtl8152_probe() is missing a call to release
firmware. Add it in to match what's in the cleanup code in
rtl8152_disconnect().

Fixes: 9370f2d05a2a ("r8152: support request_firmware for RTL8153")
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>r8152: Cancel hw_phy_work if we have an error in probe</title>
<updated>2023-10-22T10:46:17+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2023-10-20T21:06:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bb8adff9123e492598162ac1baad01a53891aef6'/>
<id>bb8adff9123e492598162ac1baad01a53891aef6</id>
<content type='text'>
The error handling in rtl8152_probe() is missing a call to cancel the
hw_phy_work. Add it in to match what's in the cleanup code in
rtl8152_disconnect().

Fixes: a028a9e003f2 ("r8152: move the settings of PHY to a work queue")
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The error handling in rtl8152_probe() is missing a call to cancel the
hw_phy_work. Add it in to match what's in the cleanup code in
rtl8152_disconnect().

Fixes: a028a9e003f2 ("r8152: move the settings of PHY to a work queue")
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>r8152: Run the unload routine if we have errors during probe</title>
<updated>2023-10-22T10:46:17+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2023-10-20T21:06:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5dd17689526971c5ae12bc8398f34bd68cd0499e'/>
<id>5dd17689526971c5ae12bc8398f34bd68cd0499e</id>
<content type='text'>
The rtl8152_probe() function lacks a call to the chip-specific
unload() routine when it sees an error in probe. Add it in to match
the cleanup code in rtl8152_disconnect().

Fixes: ac718b69301c ("net/usb: new driver for RTL8152")
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The rtl8152_probe() function lacks a call to the chip-specific
unload() routine when it sees an error in probe. Add it in to match
the cleanup code in rtl8152_disconnect().

Fixes: ac718b69301c ("net/usb: new driver for RTL8152")
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>r8152: Increase USB control msg timeout to 5000ms as per spec</title>
<updated>2023-10-22T10:46:17+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2023-10-20T21:06:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a5feba71ec9c14a54c3babdc732c5b6866d8ee43'/>
<id>a5feba71ec9c14a54c3babdc732c5b6866d8ee43</id>
<content type='text'>
According to the comment next to USB_CTRL_GET_TIMEOUT and
USB_CTRL_SET_TIMEOUT, although sending/receiving control messages is
usually quite fast, the spec allows them to take up to 5 seconds.
Let's increase the timeout in the Realtek driver from 500ms to 5000ms
(using the #defines) to account for this.

This is not just a theoretical change. The need for the longer timeout
was seen in testing. Specifically, if you drop a sc7180-trogdor based
Chromebook into the kdb debugger and then "go" again after sitting in
the debugger for a while, the next USB control message takes a long
time. Out of ~40 tests the slowest USB control message was 4.5
seconds.

While dropping into kdb is not exactly an end-user scenario, the above
is similar to what could happen due to an temporary interrupt storm,
what could happen if there was a host controller (HW or SW) issue, or
what could happen if the Realtek device got into a confused state and
needed time to recover.

This change is fairly critical since the r8152 driver in Linux doesn't
expect register reads/writes (which are backed by USB control
messages) to fail.

Fixes: ac718b69301c ("net/usb: new driver for RTL8152")
Suggested-by: Hayes Wang &lt;hayeswang@realtek.com&gt;
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
According to the comment next to USB_CTRL_GET_TIMEOUT and
USB_CTRL_SET_TIMEOUT, although sending/receiving control messages is
usually quite fast, the spec allows them to take up to 5 seconds.
Let's increase the timeout in the Realtek driver from 500ms to 5000ms
(using the #defines) to account for this.

This is not just a theoretical change. The need for the longer timeout
was seen in testing. Specifically, if you drop a sc7180-trogdor based
Chromebook into the kdb debugger and then "go" again after sitting in
the debugger for a while, the next USB control message takes a long
time. Out of ~40 tests the slowest USB control message was 4.5
seconds.

While dropping into kdb is not exactly an end-user scenario, the above
is similar to what could happen due to an temporary interrupt storm,
what could happen if there was a host controller (HW or SW) issue, or
what could happen if the Realtek device got into a confused state and
needed time to recover.

This change is fairly critical since the r8152 driver in Linux doesn't
expect register reads/writes (which are backed by USB control
messages) to fail.

Fixes: ac718b69301c ("net/usb: new driver for RTL8152")
Suggested-by: Hayes Wang &lt;hayeswang@realtek.com&gt;
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Reviewed-by: Grant Grundler &lt;grundler@chromium.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: usb: smsc95xx: Fix uninit-value access in smsc95xx_read_reg</title>
<updated>2023-10-22T10:39:26+00:00</updated>
<author>
<name>Shigeru Yoshida</name>
<email>syoshida@redhat.com</email>
</author>
<published>2023-10-20T17:03:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=51a32e828109b4a209efde44505baa356b37a4ce'/>
<id>51a32e828109b4a209efde44505baa356b37a4ce</id>
<content type='text'>
syzbot reported the following uninit-value access issue [1]:

smsc95xx 1-1:0.0 (unnamed net_device) (uninitialized): Failed to read reg index 0x00000030: -32
smsc95xx 1-1:0.0 (unnamed net_device) (uninitialized): Error reading E2P_CMD
=====================================================
BUG: KMSAN: uninit-value in smsc95xx_reset+0x409/0x25f0 drivers/net/usb/smsc95xx.c:896
 smsc95xx_reset+0x409/0x25f0 drivers/net/usb/smsc95xx.c:896
 smsc95xx_bind+0x9bc/0x22e0 drivers/net/usb/smsc95xx.c:1131
 usbnet_probe+0x100b/0x4060 drivers/net/usb/usbnet.c:1750
 usb_probe_interface+0xc75/0x1210 drivers/usb/core/driver.c:396
 really_probe+0x506/0xf40 drivers/base/dd.c:658
 __driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800
 driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830
 __device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958
 bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457
 __device_attach+0x3bd/0x640 drivers/base/dd.c:1030
 device_initial_probe+0x32/0x40 drivers/base/dd.c:1079
 bus_probe_device+0x3d8/0x5a0 drivers/base/bus.c:532
 device_add+0x16ae/0x1f20 drivers/base/core.c:3622
 usb_set_configuration+0x31c9/0x38c0 drivers/usb/core/message.c:2207
 usb_generic_driver_probe+0x109/0x2a0 drivers/usb/core/generic.c:238
 usb_probe_device+0x290/0x4a0 drivers/usb/core/driver.c:293
 really_probe+0x506/0xf40 drivers/base/dd.c:658
 __driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800
 driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830
 __device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958
 bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457
 __device_attach+0x3bd/0x640 drivers/base/dd.c:1030
 device_initial_probe+0x32/0x40 drivers/base/dd.c:1079
 bus_probe_device+0x3d8/0x5a0 drivers/base/bus.c:532
 device_add+0x16ae/0x1f20 drivers/base/core.c:3622
 usb_new_device+0x15f6/0x22f0 drivers/usb/core/hub.c:2589
 hub_port_connect drivers/usb/core/hub.c:5440 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5580 [inline]
 port_event drivers/usb/core/hub.c:5740 [inline]
 hub_event+0x53bc/0x7290 drivers/usb/core/hub.c:5822
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3e8/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Local variable buf.i225 created at:
 smsc95xx_read_reg drivers/net/usb/smsc95xx.c:90 [inline]
 smsc95xx_reset+0x203/0x25f0 drivers/net/usb/smsc95xx.c:892
 smsc95xx_bind+0x9bc/0x22e0 drivers/net/usb/smsc95xx.c:1131

CPU: 1 PID: 773 Comm: kworker/1:2 Not tainted 6.6.0-rc1-syzkaller-00125-ge42bebf6db29 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Workqueue: usb_hub_wq hub_event
=====================================================

Similar to e9c65989920f ("net: usb: smsc75xx: Fix uninit-value access in
__smsc75xx_read_reg"), this issue is caused because usbnet_read_cmd() reads
less bytes than requested (zero byte in the reproducer). In this case,
'buf' is not properly filled.

This patch fixes the issue by returning -ENODATA if usbnet_read_cmd() reads
less bytes than requested.

sysbot reported similar uninit-value access issue [2]. The root cause is
the same as mentioned above, and this patch addresses it as well.

Fixes: 2f7ca802bdae ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver")
Reported-and-tested-by: syzbot+c74c24b43c9ae534f0e0@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+2c97a98a5ba9ea9c23bd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c74c24b43c9ae534f0e0 [1]
Closes: https://syzkaller.appspot.com/bug?extid=2c97a98a5ba9ea9c23bd [2]
Signed-off-by: Shigeru Yoshida &lt;syoshida@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzbot reported the following uninit-value access issue [1]:

smsc95xx 1-1:0.0 (unnamed net_device) (uninitialized): Failed to read reg index 0x00000030: -32
smsc95xx 1-1:0.0 (unnamed net_device) (uninitialized): Error reading E2P_CMD
=====================================================
BUG: KMSAN: uninit-value in smsc95xx_reset+0x409/0x25f0 drivers/net/usb/smsc95xx.c:896
 smsc95xx_reset+0x409/0x25f0 drivers/net/usb/smsc95xx.c:896
 smsc95xx_bind+0x9bc/0x22e0 drivers/net/usb/smsc95xx.c:1131
 usbnet_probe+0x100b/0x4060 drivers/net/usb/usbnet.c:1750
 usb_probe_interface+0xc75/0x1210 drivers/usb/core/driver.c:396
 really_probe+0x506/0xf40 drivers/base/dd.c:658
 __driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800
 driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830
 __device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958
 bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457
 __device_attach+0x3bd/0x640 drivers/base/dd.c:1030
 device_initial_probe+0x32/0x40 drivers/base/dd.c:1079
 bus_probe_device+0x3d8/0x5a0 drivers/base/bus.c:532
 device_add+0x16ae/0x1f20 drivers/base/core.c:3622
 usb_set_configuration+0x31c9/0x38c0 drivers/usb/core/message.c:2207
 usb_generic_driver_probe+0x109/0x2a0 drivers/usb/core/generic.c:238
 usb_probe_device+0x290/0x4a0 drivers/usb/core/driver.c:293
 really_probe+0x506/0xf40 drivers/base/dd.c:658
 __driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800
 driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830
 __device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958
 bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457
 __device_attach+0x3bd/0x640 drivers/base/dd.c:1030
 device_initial_probe+0x32/0x40 drivers/base/dd.c:1079
 bus_probe_device+0x3d8/0x5a0 drivers/base/bus.c:532
 device_add+0x16ae/0x1f20 drivers/base/core.c:3622
 usb_new_device+0x15f6/0x22f0 drivers/usb/core/hub.c:2589
 hub_port_connect drivers/usb/core/hub.c:5440 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5580 [inline]
 port_event drivers/usb/core/hub.c:5740 [inline]
 hub_event+0x53bc/0x7290 drivers/usb/core/hub.c:5822
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3e8/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Local variable buf.i225 created at:
 smsc95xx_read_reg drivers/net/usb/smsc95xx.c:90 [inline]
 smsc95xx_reset+0x203/0x25f0 drivers/net/usb/smsc95xx.c:892
 smsc95xx_bind+0x9bc/0x22e0 drivers/net/usb/smsc95xx.c:1131

CPU: 1 PID: 773 Comm: kworker/1:2 Not tainted 6.6.0-rc1-syzkaller-00125-ge42bebf6db29 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Workqueue: usb_hub_wq hub_event
=====================================================

Similar to e9c65989920f ("net: usb: smsc75xx: Fix uninit-value access in
__smsc75xx_read_reg"), this issue is caused because usbnet_read_cmd() reads
less bytes than requested (zero byte in the reproducer). In this case,
'buf' is not properly filled.

This patch fixes the issue by returning -ENODATA if usbnet_read_cmd() reads
less bytes than requested.

sysbot reported similar uninit-value access issue [2]. The root cause is
the same as mentioned above, and this patch addresses it as well.

Fixes: 2f7ca802bdae ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver")
Reported-and-tested-by: syzbot+c74c24b43c9ae534f0e0@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+2c97a98a5ba9ea9c23bd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c74c24b43c9ae534f0e0 [1]
Closes: https://syzkaller.appspot.com/bug?extid=2c97a98a5ba9ea9c23bd [2]
Signed-off-by: Shigeru Yoshida &lt;syoshida@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: usb: smsc95xx: Fix an error code in smsc95xx_reset()</title>
<updated>2023-10-18T00:53:36+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@linaro.org</email>
</author>
<published>2023-10-16T17:28:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c53647a5df9e66dd9fedf240198e1fe50d88c286'/>
<id>c53647a5df9e66dd9fedf240198e1fe50d88c286</id>
<content type='text'>
Return a negative error code instead of success.

Fixes: 2f7ca802bdae ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/147927f0-9ada-45cc-81ff-75a19dd30b76@moroto.mountain
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Return a negative error code instead of success.

Fixes: 2f7ca802bdae ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@linaro.org&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/147927f0-9ada-45cc-81ff-75a19dd30b76@moroto.mountain
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
