[Bug 2121978] Re: Subiquity crashes for 1 malformed network adapter name.

William Hunt 2121978 at bugs.launchpad.net
Wed Sep 3 19:18:06 UTC 2025


Realised that the traceback message shows the characters are not Unicode
characters, and the name shouldn't be read. However, this still
shouldn't cause the entire installation to stop, since I was able to
install using Ethernet. It should give the user a warning that the
adapter was unable to be read due to an encoding issue.

** Summary changed:

- Subiquity crashes for non-ASCII network adapter names
+ Subiquity crashes for 1 malformed network adapter name.

** Description changed:

  Booting the live installer gave a UnicodeDecodeError when trying to read
- my Wi-Fi card as there are some non-ASCII characters appended to its
+ my Wi-Fi card as there are some malformed characters appended to its
  name as it appears in Window's Disk Management (2nd image in the
  uploaded PDF). The "Friendly Name" as it appears in the Windows Registry
  is "MediaTek Wi-Fi 6E MT7922 (RZ616) 160MHz PCIe Adapter", and the
  description is "@oem22.inf,%rz616.devicedescexc%;MediaTek Wi-Fi 6E
  MT7922 (RZ616) 160MHz PCIe Adapter". Those are both similar but
  different to the name that appears on the installer, but it has "USB WW
  WLAN<?>R<<?><?>N/A" appended, where "<?>" are non-ASCII characters that
- are unable to be displayed. This is likely a bug in the Wi-Fi adapter's
- firmware or EEPROM data, but giving a fatal crash from being unable to
- handle Unicode characters is a bug in Subiquity. Since Ubuntu should be
- designed for general users unlike other more involved distros like Arch,
- encoding issues should all be handled by Subiquity and not by the user.
+ are unable to be displayed. The traceback shows `'utf-8' codec can't
+ decode byte 0xec in position 80`, which means the bytes aren't invalid.
+ This is likely a bug in the Wi-Fi adapter's firmware or EEPROM data, but
+ giving a fatal crash from reading malformed characters shouldn't cause a
+ crash, just a warning that one of the network adapters wasn't able to be
+ read. Since Ubuntu should be designed for general users unlike other
+ more involved distros like Arch, encoding issues should all be handled
+ by Subiquity and not have to be fixed by the user.
  
  The only workaround I found was to disable the adapter before the error
  appeared (this had to be done in < 5 seconds), trying to disable the
  adapter after the error by re-running the installer just gives the same
  error, and subsequent runs of the installer result in the loading icon
  just spinning forever with nothing else being shown. If the name I had
  to type was longer, I probably wouldn't have been able to remove the
  module before the error occurred, so this fix isn't reliable. Walking
  through the installer after fixing the network adapter issue, it also
  quit at random button presses the first 3 times, but eventually I was
  able to install Ubuntu. I'm not sure whether this is related to removing
  the module, but I'll include it in this bug report in case it is. This
  issue occurred with another USB, and I was able to install Debian on my
  laptop without any issues.
  
  I assume this bug can be reproduced by any Wi-Fi network adapter with
  non-ASCII characters presented. The fix for this could involve either
  just using UTF-16 as the encoding to be used for the network adapter
  names if that's possible to do when calling the Python libraries that
  end up calling `encode_unicode_string`, or by having a catch block to
  attempt to decode the adapter name using UTF-16.

** Description changed:

  Booting the live installer gave a UnicodeDecodeError when trying to read
  my Wi-Fi card as there are some malformed characters appended to its
  name as it appears in Window's Disk Management (2nd image in the
  uploaded PDF). The "Friendly Name" as it appears in the Windows Registry
  is "MediaTek Wi-Fi 6E MT7922 (RZ616) 160MHz PCIe Adapter", and the
  description is "@oem22.inf,%rz616.devicedescexc%;MediaTek Wi-Fi 6E
  MT7922 (RZ616) 160MHz PCIe Adapter". Those are both similar but
  different to the name that appears on the installer, but it has "USB WW
  WLAN<?>R<<?><?>N/A" appended, where "<?>" are non-ASCII characters that
  are unable to be displayed. The traceback shows `'utf-8' codec can't
  decode byte 0xec in position 80`, which means the bytes aren't invalid.
  This is likely a bug in the Wi-Fi adapter's firmware or EEPROM data, but
- giving a fatal crash from reading malformed characters shouldn't cause a
- crash, just a warning that one of the network adapters wasn't able to be
- read. Since Ubuntu should be designed for general users unlike other
- more involved distros like Arch, encoding issues should all be handled
- by Subiquity and not have to be fixed by the user.
+ giving a fatal crash from reading malformed characters I would consider
+ as a bug in Subiquity as 1 adapter being unusable doesn't usually
+ prevent the installation. Just a warning that one of the network
+ adapters wasn't able to be read would be ideal. Since Ubuntu should be
+ designed for general users unlike other more involved distros like Arch,
+ encoding issues should all be handled by Subiquity and not have to be
+ fixed by the user.
  
  The only workaround I found was to disable the adapter before the error
  appeared (this had to be done in < 5 seconds), trying to disable the
  adapter after the error by re-running the installer just gives the same
  error, and subsequent runs of the installer result in the loading icon
  just spinning forever with nothing else being shown. If the name I had
  to type was longer, I probably wouldn't have been able to remove the
  module before the error occurred, so this fix isn't reliable. Walking
  through the installer after fixing the network adapter issue, it also
  quit at random button presses the first 3 times, but eventually I was
  able to install Ubuntu. I'm not sure whether this is related to removing
  the module, but I'll include it in this bug report in case it is. This
  issue occurred with another USB, and I was able to install Debian on my
  laptop without any issues.
  
  I assume this bug can be reproduced by any Wi-Fi network adapter with
  non-ASCII characters presented. The fix for this could involve either
  just using UTF-16 as the encoding to be used for the network adapter
  names if that's possible to do when calling the Python libraries that
  end up calling `encode_unicode_string`, or by having a catch block to
  attempt to decode the adapter name using UTF-16.

** Description changed:

  Booting the live installer gave a UnicodeDecodeError when trying to read
  my Wi-Fi card as there are some malformed characters appended to its
- name as it appears in Window's Disk Management (2nd image in the
- uploaded PDF). The "Friendly Name" as it appears in the Windows Registry
- is "MediaTek Wi-Fi 6E MT7922 (RZ616) 160MHz PCIe Adapter", and the
- description is "@oem22.inf,%rz616.devicedescexc%;MediaTek Wi-Fi 6E
+ name (not as it appears in Window's Disk Management) in the 2nd image in
+ the uploaded PDF). The "Friendly Name" as it appears in the Windows
+ Registry is "MediaTek Wi-Fi 6E MT7922 (RZ616) 160MHz PCIe Adapter", and
+ the description is "@oem22.inf,%rz616.devicedescexc%;MediaTek Wi-Fi 6E
  MT7922 (RZ616) 160MHz PCIe Adapter". Those are both similar but
  different to the name that appears on the installer, but it has "USB WW
  WLAN<?>R<<?><?>N/A" appended, where "<?>" are non-ASCII characters that
  are unable to be displayed. The traceback shows `'utf-8' codec can't
  decode byte 0xec in position 80`, which means the bytes aren't invalid.
  This is likely a bug in the Wi-Fi adapter's firmware or EEPROM data, but
  giving a fatal crash from reading malformed characters I would consider
  as a bug in Subiquity as 1 adapter being unusable doesn't usually
  prevent the installation. Just a warning that one of the network
  adapters wasn't able to be read would be ideal. Since Ubuntu should be
  designed for general users unlike other more involved distros like Arch,
  encoding issues should all be handled by Subiquity and not have to be
  fixed by the user.
  
  The only workaround I found was to disable the adapter before the error
  appeared (this had to be done in < 5 seconds), trying to disable the
  adapter after the error by re-running the installer just gives the same
  error, and subsequent runs of the installer result in the loading icon
  just spinning forever with nothing else being shown. If the name I had
  to type was longer, I probably wouldn't have been able to remove the
  module before the error occurred, so this fix isn't reliable. Walking
  through the installer after fixing the network adapter issue, it also
  quit at random button presses the first 3 times, but eventually I was
  able to install Ubuntu. I'm not sure whether this is related to removing
  the module, but I'll include it in this bug report in case it is. This
  issue occurred with another USB, and I was able to install Debian on my
  laptop without any issues.
  
  I assume this bug can be reproduced by any Wi-Fi network adapter with
  non-ASCII characters presented. The fix for this could involve either
  just using UTF-16 as the encoding to be used for the network adapter
  names if that's possible to do when calling the Python libraries that
  end up calling `encode_unicode_string`, or by having a catch block to
  attempt to decode the adapter name using UTF-16.

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https://bugs.launchpad.net/bugs/2121978

Title:
  Subiquity crashes for 1 malformed network adapter name.

Status in subiquity package in Ubuntu:
  New

Bug description:
  Booting the live installer gave a UnicodeDecodeError when trying to
  read my Wi-Fi card as there are some malformed characters appended to
  its name (not as it appears in Window's Disk Management) in the 2nd
  image in the uploaded PDF). The "Friendly Name" as it appears in the
  Windows Registry is "MediaTek Wi-Fi 6E MT7922 (RZ616) 160MHz PCIe
  Adapter", and the description is
  "@oem22.inf,%rz616.devicedescexc%;MediaTek Wi-Fi 6E MT7922 (RZ616)
  160MHz PCIe Adapter". Those are both similar but different to the name
  that appears on the installer, but it has "USB WW WLAN<?>R<<?><?>N/A"
  appended, where "<?>" are non-ASCII characters that are unable to be
  displayed. The traceback shows `'utf-8' codec can't decode byte 0xec
  in position 80`, which means the bytes aren't invalid. This is likely
  a bug in the Wi-Fi adapter's firmware or EEPROM data, but giving a
  fatal crash from reading malformed characters I would consider as a
  bug in Subiquity as 1 adapter being unusable doesn't usually prevent
  the installation. Just a warning that one of the network adapters
  wasn't able to be read would be ideal. Since Ubuntu should be designed
  for general users unlike other more involved distros like Arch,
  encoding issues should all be handled by Subiquity and not have to be
  fixed by the user.

  The only workaround I found was to disable the adapter before the
  error appeared (this had to be done in < 5 seconds), trying to disable
  the adapter after the error by re-running the installer just gives the
  same error, and subsequent runs of the installer result in the loading
  icon just spinning forever with nothing else being shown. If the name
  I had to type was longer, I probably wouldn't have been able to remove
  the module before the error occurred, so this fix isn't reliable.
  Walking through the installer after fixing the network adapter issue,
  it also quit at random button presses the first 3 times, but
  eventually I was able to install Ubuntu. I'm not sure whether this is
  related to removing the module, but I'll include it in this bug report
  in case it is. This issue occurred with another USB, and I was able to
  install Debian on my laptop without any issues.

  I assume this bug can be reproduced by any Wi-Fi network adapter with
  non-ASCII characters presented. The fix for this could involve either
  just using UTF-16 as the encoding to be used for the network adapter
  names if that's possible to do when calling the Python libraries that
  end up calling `encode_unicode_string`, or by having a catch block to
  attempt to decode the adapter name using UTF-16.

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