[Bug 1850184] Re: losetup -f broken in 2.0.6-1ubuntu2

[Launchpad Bug Tracker]

This bug was fixed in the package klibc - 2.0.7-1ubuntu1

---------------
klibc (2.0.7-1ubuntu1) focal; urgency=low

  * Merge from Debian unstable.  Remaining changes:
    * Fix FTBFS on eoan and later with new gcc
      - cf-protection.patch: Disable cf-protection for syscalls stub.

  * save-argc.patch: when build with gcc-9 linux-5.3, calling ioctl,
    clears global argc, thus save it, to compare to it later. Otheriwse
    losetup -f is broken LP: #1850184

klibc (2.0.7-1) unstable; urgency=medium

  [ Ben Hutchings ]
  * New upstream version:
    - klcc: Enable stripping even if CONFIG_DEBUG_INFO is enabled
    - run-init: Allow the initramfs to be persisted across root changes
      (thanks to Matthew Garrett)
    - ipconfig: Implement support -d ...:dns0:dns1 options (Closes: #931416)
    - Kbuild: Work around broken "ar s" in binutils 2.32 (see #941921)
  * debian/rules: Reorganise make flags variables
  * debian/rules: Define ARCH for klibc, for all architectures
  * debian/rules: Delete redundant architecture mappings
  * debian/rules: Delete redundant export
  * klibc-utils: Trigger update-initramfs on install/upgrade
  * initramfs-tools: Don't install commands that already exist in /sbin
  * initramfs-tools: Exclude kinit and zcat commands earlier
  * initramfs-tools: Exclude gzip command
  * Drop "resume: Backward compatibility for resume_offset", which will
    not be needed in the next release
  * [klibc] fstype: Drop obsolete support for "ext4dev" (Closes: #932926)
  * debian/control: Set Maintainer to Debian Kernel Team; move maks to
    Uploaders

  [ James Clarke ]
  * debian/control: Restrict m4 build dependency to just sparc

  [ Helmut Grohne ]
  * Honour DEB_BUILD_OPTIONS=nocheck. (Closes: #922814)

 -- Dimitri John Ledkov <xnox at ubuntu.com>  Thu, 31 Oct 2019 11:50:44
+0000

** Changed in: klibc (Ubuntu Focal)
       Status: New => Fix Released

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to klibc in Ubuntu.
https://bugs.launchpad.net/bugs/1850184

Title:
  losetup -f broken in 2.0.6-1ubuntu2

Status in gcc-9 package in Ubuntu:
  New
Status in klibc package in Ubuntu:
  Fix Released
Status in linux package in Ubuntu:
  Incomplete
Status in gcc-9 source package in Eoan:
  New
Status in klibc source package in Eoan:
  New
Status in linux source package in Eoan:
  Incomplete
Status in gcc-9 source package in Focal:
  New
Status in klibc source package in Focal:
  Fix Released
Status in linux source package in Focal:
  Incomplete

Bug description:
  [Impact]

   * sudo /usr/lib/klibc/bin/losetup -vf, which appears to be missbuilt,
  as main(argc) is reset to zero, after ioctl() operations in a function
  call, quite unexpectadly.

  [Test Case]

   * $ sudo /usr/lib/klibc/bin/losetup -vf
  Loop device is /dev/loop20
  loop: can't get info on device /dev/loop20: No such device or address

  is bad.

  Note that ioctl() must succeed, thus loop0 device must be configured
  to trigger the bug.

  
  [Regression Potential]

   * klibc is quite special, as it uses linux kernel headers/assembly.
  It seems like there is incompatibility between klibc sources, and
  gcc-9 with linux-5.3 when used to build userspace programmes.

   * disabling cf-protection and stack-clash-protection did not help.

   * building with gcc-8 does not exhibit the problem.

   * the workaround is quite simple in the code, keep a copy of argc to
  compare to it later in the code.

  [Other Info]

   * Original bug report

  http://autopkgtest.ubuntu.com/packages/c/casper/focal/amd64

  https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac
  /autopkgtest-focal/focal/amd64/c/casper/20191025_214555_df8b8@/log.gz

  ...
  [   11.751912] EXT4-fs (sda1): mounting ext2 file system using the ext4 subsystem
  [   11.761441] EXT4-fs (sda1): mounted filesystem without journal. Opts: (null)
  loop: can't get info on device /dev/loop1: No such device or address

  BusyBox v1.30.1 (Ubuntu 1:1.30.1-4ubuntu4) built-in shell (ash)
  Enter 'help' for a list of built-in commands.

  (initramfs) + mkdir result
  + set -x
  + read LINE
  + grep -e '^--OUT .* BEGIN-- .* --END--$' qemu-output.txt
  ++ grep -q /rofs result/lsblk.txt
  grep: result/lsblk.txt: No such file or directory
  autopkgtest [21:45:45]: test boot: -----------------------]
  autopkgtest [21:45:45]: test boot:  - - - - - - - - - - results - - - - - - - - - -
  boot                 FAIL non-zero exit status 2
  autopkgtest [21:45:45]: @@@@@@@@@@@@@@@@@@@@ summary
  boot                 FAIL non-zero exit status 2
  ...

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/gcc-9/+bug/1850184/+subscriptions