linux-stable.git/drivers/net/usb, branch v4.9.288 Linux kernel stable tree r8152: select CRC32 and CRYPTO/CRYPTO_HASH/CRYPTO_SHA256 2021-10-27T07:33:59+00:00 Vegard Nossum vegard.nossum@oracle.com 2021-10-11T15:22:49+00:00 4b345af2be6c2390dc69513017e44518ad639598 commit 9973a43012b6ad1720dbc4d5faf5302c28635b8c upstream. Fix the following build/link errors by adding a dependency on CRYPTO, CRYPTO_HASH, CRYPTO_SHA256 and CRC32: ld: drivers/net/usb/r8152.o: in function `rtl8152_fw_verify_checksum': r8152.c:(.text+0x2b2a): undefined reference to `crypto_alloc_shash' ld: r8152.c:(.text+0x2bed): undefined reference to `crypto_shash_digest' ld: r8152.c:(.text+0x2c50): undefined reference to `crypto_destroy_tfm' ld: drivers/net/usb/r8152.o: in function `_rtl8152_set_rx_mode': r8152.c:(.text+0xdcb0): undefined reference to `crc32_le' Fixes: 9370f2d05a2a1 ("r8152: support request_firmware for RTL8153") Fixes: ac718b69301c7 ("net/usb: new driver for RTL8152") Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9973a43012b6ad1720dbc4d5faf5302c28635b8c upstream.

Fix the following build/link errors by adding a dependency on
CRYPTO, CRYPTO_HASH, CRYPTO_SHA256 and CRC32:

  ld: drivers/net/usb/r8152.o: in function `rtl8152_fw_verify_checksum':
  r8152.c:(.text+0x2b2a): undefined reference to `crypto_alloc_shash'
  ld: r8152.c:(.text+0x2bed): undefined reference to `crypto_shash_digest'
  ld: r8152.c:(.text+0x2c50): undefined reference to `crypto_destroy_tfm'
  ld: drivers/net/usb/r8152.o: in function `_rtl8152_set_rx_mode':
  r8152.c:(.text+0xdcb0): undefined reference to `crc32_le'

Fixes: 9370f2d05a2a1 ("r8152: support request_firmware for RTL8153")
Fixes: ac718b69301c7 ("net/usb: new driver for RTL8152")
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: hso: fix muxed tty registration 2021-10-06T08:23:39+00:00 Johan Hovold johan@kernel.org 2021-09-17T10:12:04+00:00 77fe87952e4d01790c645e163d3d4d9218a7a1fe commit e8f69b16ee776da88589b5271e3f46020efc8f6c upstream. If resource allocation and registration fail for a muxed tty device (e.g. if there are no more minor numbers) the driver should not try to deregister the never-registered (or already-deregistered) tty. Fix up the error handling to avoid dereferencing a NULL pointer when attempting to remove the character device. Fixes: 72dc1c096c70 ("HSO: add option hso driver") Cc: stable@vger.kernel.org # 2.6.27 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e8f69b16ee776da88589b5271e3f46020efc8f6c upstream.

If resource allocation and registration fail for a muxed tty device
(e.g. if there are no more minor numbers) the driver should not try to
deregister the never-registered (or already-deregistered) tty.

Fix up the error handling to avoid dereferencing a NULL pointer when
attempting to remove the character device.

Fixes: 72dc1c096c70 ("HSO: add option hso driver")
Cc: stable@vger.kernel.org	# 2.6.27
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: usb: cdc_mbim: avoid altsetting toggling for Telit LN920 2021-09-22T09:43:10+00:00 Daniele Palmas dnlplm@gmail.com 2021-09-02T10:51:22+00:00 33920b67ea935f306d6558c316891dda51acdddf [ Upstream commit aabbdc67f3485b5db27ab4eba01e5fbf1ffea62c ] Add quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE for Telit LN920 0x1061 composition in order to avoid bind error. Signed-off-by: Daniele Palmas <dnlplm@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aabbdc67f3485b5db27ab4eba01e5fbf1ffea62c ]

Add quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE for Telit LN920
0x1061 composition in order to avoid bind error.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: pegasus: fix uninit-value in get_interrupt_interval 2021-08-15T11:01:02+00:00 Pavel Skripkin paskripkin@gmail.com 2021-08-04T14:30:05+00:00 10fb322e7cca7b9e523c6e7099cf4269e3811918 [ Upstream commit af35fc37354cda3c9c8cc4961b1d24bdc9d27903 ] Syzbot reported uninit value pegasus_probe(). The problem was in missing error handling. get_interrupt_interval() internally calls read_eprom_word() which can fail in some cases. For example: failed to receive usb control message. These cases should be handled to prevent uninit value bug, since read_eprom_word() will not initialize passed stack variable in case of internal failure. Fail log: BUG: KMSAN: uninit-value in get_interrupt_interval drivers/net/usb/pegasus.c:746 [inline] BUG: KMSAN: uninit-value in pegasus_probe+0x10e7/0x4080 drivers/net/usb/pegasus.c:1152 CPU: 1 PID: 825 Comm: kworker/1:1 Not tainted 5.12.0-rc6-syzkaller #0 ... Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x24c/0x2e0 lib/dump_stack.c:120 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197 get_interrupt_interval drivers/net/usb/pegasus.c:746 [inline] pegasus_probe+0x10e7/0x4080 drivers/net/usb/pegasus.c:1152 .... Local variable ----data.i@pegasus_probe created at: get_interrupt_interval drivers/net/usb/pegasus.c:1151 [inline] pegasus_probe+0xe57/0x4080 drivers/net/usb/pegasus.c:1152 get_interrupt_interval drivers/net/usb/pegasus.c:1151 [inline] pegasus_probe+0xe57/0x4080 drivers/net/usb/pegasus.c:1152 Reported-and-tested-by: syzbot+02c9f70f3afae308464a@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Link: https://lore.kernel.org/r/20210804143005.439-1-paskripkin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit af35fc37354cda3c9c8cc4961b1d24bdc9d27903 ]

Syzbot reported uninit value pegasus_probe(). The problem was in missing
error handling.

get_interrupt_interval() internally calls read_eprom_word() which can
fail in some cases. For example: failed to receive usb control message.
These cases should be handled to prevent uninit value bug, since
read_eprom_word() will not initialize passed stack variable in case of
internal failure.

Fail log:

BUG: KMSAN: uninit-value in get_interrupt_interval drivers/net/usb/pegasus.c:746 [inline]
BUG: KMSAN: uninit-value in pegasus_probe+0x10e7/0x4080 drivers/net/usb/pegasus.c:1152
CPU: 1 PID: 825 Comm: kworker/1:1 Not tainted 5.12.0-rc6-syzkaller #0
...
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 get_interrupt_interval drivers/net/usb/pegasus.c:746 [inline]
 pegasus_probe+0x10e7/0x4080 drivers/net/usb/pegasus.c:1152
....

Local variable ----data.i@pegasus_probe created at:
 get_interrupt_interval drivers/net/usb/pegasus.c:1151 [inline]
 pegasus_probe+0xe57/0x4080 drivers/net/usb/pegasus.c:1152
 get_interrupt_interval drivers/net/usb/pegasus.c:1151 [inline]
 pegasus_probe+0xe57/0x4080 drivers/net/usb/pegasus.c:1152

Reported-and-tested-by: syzbot+02c9f70f3afae308464a@syzkaller.appspotmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/20210804143005.439-1-paskripkin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
r8152: Fix potential PM refcount imbalance 2021-08-08T06:38:53+00:00 Takashi Iwai tiwai@suse.de 2021-07-14T17:00:21+00:00 a5b9b064d3b0d737103539f1fabbba513ab49c66 [ Upstream commit 9c23aa51477a37f8b56c3c40192248db0663c196 ] rtl8152_close() takes the refcount via usb_autopm_get_interface() but it doesn't release when RTL8152_UNPLUG test hits. This may lead to the imbalance of PM refcount. This patch addresses it. Link: https://bugzilla.suse.com/show_bug.cgi?id=1186194 Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 9c23aa51477a37f8b56c3c40192248db0663c196 ]

rtl8152_close() takes the refcount via usb_autopm_get_interface() but
it doesn't release when RTL8152_UNPLUG test hits.  This may lead to
the imbalance of PM refcount.  This patch addresses it.

Link: https://bugzilla.suse.com/show_bug.cgi?id=1186194
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
r8152: Avoid memcpy() over-reading of ETH_SS_STATS 2021-06-30T12:49:21+00:00 Kees Cook keescook@chromium.org 2021-06-16T19:53:03+00:00 b05649373ee3e841e78a812d6857fe8136342ba8 [ Upstream commit 99718abdc00e86e4f286dd836408e2834886c16e ] In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memcpy(), memmove(), and memset(), avoid intentionally reading across neighboring array fields. The memcpy() is copying the entire structure, not just the first array. Adjust the source argument so the compiler can do appropriate bounds checking. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 99718abdc00e86e4f286dd836408e2834886c16e ]

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally reading across neighboring array fields.

The memcpy() is copying the entire structure, not just the first array.
Adjust the source argument so the compiler can do appropriate bounds
checking.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: cdc_eem: fix tx fixup skb leak 2021-06-30T12:49:16+00:00 Linyu Yuan linyyuan@codeaurora.org 2021-06-16T23:32:32+00:00 14184ec5c958b589ba934da7363a2877879204df [ Upstream commit c3b26fdf1b32f91c7a3bc743384b4a298ab53ad7 ] when usbnet transmit a skb, eem fixup it in eem_tx_fixup(), if skb_copy_expand() failed, it return NULL, usbnet_start_xmit() will have no chance to free original skb. fix it by free orginal skb in eem_tx_fixup() first, then check skb clone status, if failed, return NULL to usbnet. Fixes: 9f722c0978b0 ("usbnet: CDC EEM support (v5)") Signed-off-by: Linyu Yuan <linyyuan@codeaurora.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c3b26fdf1b32f91c7a3bc743384b4a298ab53ad7 ]

when usbnet transmit a skb, eem fixup it in eem_tx_fixup(),
if skb_copy_expand() failed, it return NULL,
usbnet_start_xmit() will have no chance to free original skb.

fix it by free orginal skb in eem_tx_fixup() first,
then check skb clone status, if failed, return NULL to usbnet.

Fixes: 9f722c0978b0 ("usbnet: CDC EEM support (v5)")
Signed-off-by: Linyu Yuan <linyyuan@codeaurora.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: usb: fix possible use-after-free in smsc75xx_bind 2021-06-30T12:49:15+00:00 Dongliang Mu mudongliangabcd@gmail.com 2021-06-16T02:48:33+00:00 64160d1741a3de5204d1a822e058e0b4cc526504 [ Upstream commit 56b786d86694e079d8aad9b314e015cd4ac02a3d ] The commit 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind") fails to clean up the work scheduled in smsc75xx_reset-> smsc75xx_set_multicast, which leads to use-after-free if the work is scheduled to start after the deallocation. In addition, this patch also removes a dangling pointer - dev->data[0]. This patch calls cancel_work_sync to cancel the scheduled work and set the dangling pointer to NULL. Fixes: 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind") Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 56b786d86694e079d8aad9b314e015cd4ac02a3d ]

The commit 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind")
fails to clean up the work scheduled in smsc75xx_reset->
smsc75xx_set_multicast, which leads to use-after-free if the work is
scheduled to start after the deallocation. In addition, this patch
also removes a dangling pointer - dev->data[0].

This patch calls cancel_work_sync to cancel the scheduled work and set
the dangling pointer to NULL.

Fixes: 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: cdc_ncm: switch to eth%d interface naming 2021-06-30T12:49:14+00:00 Maciej Żenczykowski maze@google.com 2021-06-15T08:05:49+00:00 4c3522ea49c64d93eb42dd15900c963dea0a034e [ Upstream commit c1a3d4067309451e68c33dbd356032549cc0bd8e ] This is meant to make the host side cdc_ncm interface consistently named just like the older CDC protocols: cdc_ether & cdc_ecm (and even rndis_host), which all use 'FLAG_ETHER | FLAG_POINTTOPOINT'. include/linux/usb/usbnet.h: #define FLAG_ETHER 0x0020 /* maybe use "eth%d" names */ #define FLAG_WLAN 0x0080 /* use "wlan%d" names */ #define FLAG_WWAN 0x0400 /* use "wwan%d" names */ #define FLAG_POINTTOPOINT 0x1000 /* possibly use "usb%d" names */ drivers/net/usb/usbnet.c @ line 1711: strcpy (net->name, "usb%d"); ... // heuristic: "usb%d" for links we know are two-host, // else "eth%d" when there's reasonable doubt. userspace // can rename the link if it knows better. if ((dev->driver_info->flags & FLAG_ETHER) != 0 && ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 || (net->dev_addr [0] & 0x02) == 0)) strcpy (net->name, "eth%d"); /* WLAN devices should always be named "wlan%d" */ if ((dev->driver_info->flags & FLAG_WLAN) != 0) strcpy(net->name, "wlan%d"); /* WWAN devices should always be named "wwan%d" */ if ((dev->driver_info->flags & FLAG_WWAN) != 0) strcpy(net->name, "wwan%d"); So by using ETHER | POINTTOPOINT the interface naming is either usb%d or eth%d based on the global uniqueness of the mac address of the device. Without this 2.5gbps ethernet dongles which all seem to use the cdc_ncm driver end up being called usb%d instead of eth%d even though they're definitely not two-host. (All 1gbps & 5gbps ethernet usb dongles I've tested don't hit this problem due to use of different drivers, primarily r8152 and aqc111) Fixes tag is based purely on git blame, and is really just here to make sure this hits LTS branches newer than v4.5. Cc: Lorenzo Colitti <lorenzo@google.com> Fixes: 4d06dd537f95 ("cdc_ncm: do not call usbnet_link_change from cdc_ncm_bind") Signed-off-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c1a3d4067309451e68c33dbd356032549cc0bd8e ]

This is meant to make the host side cdc_ncm interface consistently
named just like the older CDC protocols: cdc_ether & cdc_ecm
(and even rndis_host), which all use 'FLAG_ETHER | FLAG_POINTTOPOINT'.

include/linux/usb/usbnet.h:
  #define FLAG_ETHER	0x0020		/* maybe use "eth%d" names */
  #define FLAG_WLAN	0x0080		/* use "wlan%d" names */
  #define FLAG_WWAN	0x0400		/* use "wwan%d" names */
  #define FLAG_POINTTOPOINT 0x1000	/* possibly use "usb%d" names */

drivers/net/usb/usbnet.c @ line 1711:
  strcpy (net->name, "usb%d");
  ...
  // heuristic:  "usb%d" for links we know are two-host,
  // else "eth%d" when there's reasonable doubt.  userspace
  // can rename the link if it knows better.
  if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
      ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
       (net->dev_addr [0] & 0x02) == 0))
          strcpy (net->name, "eth%d");
  /* WLAN devices should always be named "wlan%d" */
  if ((dev->driver_info->flags & FLAG_WLAN) != 0)
          strcpy(net->name, "wlan%d");
  /* WWAN devices should always be named "wwan%d" */
  if ((dev->driver_info->flags & FLAG_WWAN) != 0)
          strcpy(net->name, "wwan%d");

So by using ETHER | POINTTOPOINT the interface naming is
either usb%d or eth%d based on the global uniqueness of the
mac address of the device.

Without this 2.5gbps ethernet dongles which all seem to use the cdc_ncm
driver end up being called usb%d instead of eth%d even though they're
definitely not two-host.  (All 1gbps & 5gbps ethernet usb dongles I've
tested don't hit this problem due to use of different drivers, primarily
r8152 and aqc111)

Fixes tag is based purely on git blame, and is really just here to make
sure this hits LTS branches newer than v4.5.

Cc: Lorenzo Colitti <lorenzo@google.com>
Fixes: 4d06dd537f95 ("cdc_ncm: do not call usbnet_link_change from cdc_ncm_bind")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: usb: cdc_ncm: don't spew notifications 2021-06-10T10:42:35+00:00 Grant Grundler grundler@chromium.org 2021-01-20T01:12:08+00:00 7246d9cfe11b818c35bfb6780ef319e3298f0bd2 [ Upstream commit de658a195ee23ca6aaffe197d1d2ea040beea0a2 ] RTL8156 sends notifications about every 32ms. Only display/log notifications when something changes. This issue has been reported by others: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1832472 https://lkml.org/lkml/2020/8/27/1083 ... [785962.779840] usb 1-1: new high-speed USB device number 5 using xhci_hcd [785962.929944] usb 1-1: New USB device found, idVendor=0bda, idProduct=8156, bcdDevice=30.00 [785962.929949] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=6 [785962.929952] usb 1-1: Product: USB 10/100/1G/2.5G LAN [785962.929954] usb 1-1: Manufacturer: Realtek [785962.929956] usb 1-1: SerialNumber: 000000001 [785962.991755] usbcore: registered new interface driver cdc_ether [785963.017068] cdc_ncm 1-1:2.0: MAC-Address: 00:24:27:88:08:15 [785963.017072] cdc_ncm 1-1:2.0: setting rx_max = 16384 [785963.017169] cdc_ncm 1-1:2.0: setting tx_max = 16384 [785963.017682] cdc_ncm 1-1:2.0 usb0: register 'cdc_ncm' at usb-0000:00:14.0-1, CDC NCM, 00:24:27:88:08:15 [785963.019211] usbcore: registered new interface driver cdc_ncm [785963.023856] usbcore: registered new interface driver cdc_wdm [785963.025461] usbcore: registered new interface driver cdc_mbim [785963.038824] cdc_ncm 1-1:2.0 enx002427880815: renamed from usb0 [785963.089586] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected [785963.121673] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected [785963.153682] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected ... This is about 2KB per second and will overwrite all contents of a 1MB dmesg buffer in under 10 minutes rendering them useless for debugging many kernel problems. This is also an extra 180 MB/day in /var/logs (or 1GB per week) rendering the majority of those logs useless too. When the link is up (expected state), spew amount is >2x higher: ... [786139.600992] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected [786139.632997] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink [786139.665097] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected [786139.697100] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink [786139.729094] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected [786139.761108] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink ... Chrome OS cannot support RTL8156 until this is fixed. Signed-off-by: Grant Grundler <grundler@chromium.org> Reviewed-by: Hayes Wang <hayeswang@realtek.com> Link: https://lore.kernel.org/r/20210120011208.3768105-1-grundler@chromium.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit de658a195ee23ca6aaffe197d1d2ea040beea0a2 ]

RTL8156 sends notifications about every 32ms.
Only display/log notifications when something changes.

This issue has been reported by others:
	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1832472
	https://lkml.org/lkml/2020/8/27/1083

...
[785962.779840] usb 1-1: new high-speed USB device number 5 using xhci_hcd
[785962.929944] usb 1-1: New USB device found, idVendor=0bda, idProduct=8156, bcdDevice=30.00
[785962.929949] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=6
[785962.929952] usb 1-1: Product: USB 10/100/1G/2.5G LAN
[785962.929954] usb 1-1: Manufacturer: Realtek
[785962.929956] usb 1-1: SerialNumber: 000000001
[785962.991755] usbcore: registered new interface driver cdc_ether
[785963.017068] cdc_ncm 1-1:2.0: MAC-Address: 00:24:27:88:08:15
[785963.017072] cdc_ncm 1-1:2.0: setting rx_max = 16384
[785963.017169] cdc_ncm 1-1:2.0: setting tx_max = 16384
[785963.017682] cdc_ncm 1-1:2.0 usb0: register 'cdc_ncm' at usb-0000:00:14.0-1, CDC NCM, 00:24:27:88:08:15
[785963.019211] usbcore: registered new interface driver cdc_ncm
[785963.023856] usbcore: registered new interface driver cdc_wdm
[785963.025461] usbcore: registered new interface driver cdc_mbim
[785963.038824] cdc_ncm 1-1:2.0 enx002427880815: renamed from usb0
[785963.089586] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected
[785963.121673] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected
[785963.153682] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected
...

This is about 2KB per second and will overwrite all contents of a 1MB
dmesg buffer in under 10 minutes rendering them useless for debugging
many kernel problems.

This is also an extra 180 MB/day in /var/logs (or 1GB per week) rendering
the majority of those logs useless too.

When the link is up (expected state), spew amount is >2x higher:
...
[786139.600992] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected
[786139.632997] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink
[786139.665097] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected
[786139.697100] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink
[786139.729094] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected
[786139.761108] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink
...

Chrome OS cannot support RTL8156 until this is fixed.

Signed-off-by: Grant Grundler <grundler@chromium.org>
Reviewed-by: Hayes Wang <hayeswang@realtek.com>
Link: https://lore.kernel.org/r/20210120011208.3768105-1-grundler@chromium.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>