gpio: Restrict usage of GPIO chip irq members before initialization

[Asmaa Mnebhi]

SRU Justification:

[Impact]

GPIO chip irq members are exposed before they could be completely
initialized and this leads to race conditions.

One such issue was observed for the gc->irq.domain variable which
was accessed through the pwr-mlxbf.c driver in gpiochip_to_irq() before
it could be initialized by gpiochip_add_irqchip(). This resulted in
Kernel NULL pointer dereference. This is a well known issue in the linux community
and was fixed via 2 commits:
5467801f1fcbdc46bc7298a84dbf3ca1ff2a7320
and
06fb4ecfeac7e00d6704fa5ed19299f2fefb3cc9 (since the previous commit caused a regression)

This race condition is intermittent and hard to reproduce.

[Fix]

* Cherry pick: 5467801f1fcbdc46bc7298a84dbf3ca1ff2a7320 to fix the bug at stake
* cherry-pick: 06fb4ecfeac7e00d6704fa5ed19299f2fefb3cc9 to fix a regression introduced by the previous commit

[Test Case]

* Check that the gpio-mlxbf2.c driver is loaded with no kernel panic
* check that all drivers dependent on gpio-mlxbf2.c driver are loaded (mlxbf-gige and pwr-mlxbf)
* do 5000 reboots to make sure this race condition no longer happens

[Regression Potential]

This could cause some regression with the use of gpio interrupts so it is important to test the dependent
drivers mlxbf-gige and pwr-mlxbf. Trigger power reset interrupt to test pwr-mlxbf and bring down/up the
oob_net0 interface to test mlxbf-gige.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-bluefield/5.4.0-1060.66 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-bluefield - 5.4.0-1060.66

---------------
linux-bluefield (5.4.0-1060.66) focal; urgency=medium

  * focal/linux-bluefield: 5.4.0-1060.66 -proposed tracker (LP: #2008364)

  * gpio: Restrict usage of GPIO chip irq members before initialization
    (LP: #2007581)
    - gpio: Restrict usage of GPIO chip irq members before initialization
    - gpio: Request interrupts after IRQ is initialized

  * netfilter: flowtable: add counter support in HW offload (LP: #2008136)
    - netfilter: conntrack: add nf_ct_acct_add()
    - netfilter: flowtable: add counter support in HW offload

  [ Ubuntu: 5.4.0-145.162 ]

  * focal/linux: 5.4.0-145.162 -proposed tracker (LP: #2008389)
  * [SRU]Update ice driver to support E823 devices (LP: #1986717)
    - ice: Add device ids for E822 devices
    - ice: add support for E823 devices
  * btrfs/154: rename fails with EOVERFLOW when calculating item size during
    item key collision (LP: #2004132)
    - btrfs: correctly calculate item size used when item key collision happens
  * rtcpie in timers from ubuntu_kernel_selftests randomly failing
    (LP: #1814234)
    - SAUCE: selftest: rtcpie: Force passing unreliable subtest
  * [UBUNTU 20.04] KVM: s390: pv: don't allow userspace to set the clock under
    PV - kernel part (LP: #1999882)
    - KVM: s390x: fix SCK locking
    - KVM: s390: pv: don't allow userspace to set the clock under PV
  * CVE-2021-3669
    - ipc: replace costly bailout check in sysvipc_find_ipc()
  * net:fcnal-test.sh 'nettest' command not found on F/K (LP: #2006391)
    - selftests/net: Find nettest in current directory
  * xfs: Preallocated ioend transactions cause deadlock due to log buffer
    exhaustion (LP: #2007219)
    - xfs: drop submit side trans alloc for append ioends
  * CVE-2022-4382
    - USB: gadgetfs: Fix race between mounting and unmounting
  * CVE-2022-2196
    - KVM: VMX: Execute IBPB on emulated VM-exit when guest has IBRS
  * ubuntu_kernel_selftests: net:udpgso_bench.sh failed (LP: #1951447)
    - selftests: net: udpgso_bench: Fix racing bug between the rx/tx programs
  * net:fcnal-test.sh didn't return a non-zero value even with some sub-tests
    failed (LP: #2006692)
    - selftests: net/fcnal-test.sh: add exit code
  * Fix selftests/ftracetests/Meta-selftests in Focal (LP: #2006453)
    - SAUCE: Fix ftrace/Meta-selftests bashism check
  * CVE-2023-23559
    - wifi: rndis_wlan: Prevent buffer overflow in rndis_query_oid

 -- Bartlomiej Zolnierkiewicz <email address hidden> Fri, 10 Mar 2023 18:15:33 +0100