[GIT PULL] pid: use flex array

[Christian Brauner]

Hey Linus,

/* Summary */
This contains Kees' work to make struct upid in struct pid a proper
flexible array and thus gets rid of a bunch of syzbot UBSAN warnings.

---

Sorry for sending this one later than the others.
It's pretty minimal though.

/* Testing */
clang: Ubuntu clang version 15.0.7
gcc: (Ubuntu 12.2.0-3ubuntu1) 12.2.0

All patches are based on v6.4-rc2 and have been sitting in linux-next.
No build failures or warnings were observed. All old and new tests in
selftests, and LTP pass without regressions.

/* Conflicts */
At the time of creating this PR no merge conflicts were reported from
linux-next and no merge conflicts showed up doing a test-merge with
current mainline.

The following changes since commit f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6:

  Linux 6.4-rc2 (2023-05-14 12:51:40 -0700)

are available in the Git repository at:

  git@xxxxxxxxxxxxxxxxxxx:pub/scm/linux/kernel/git/brauner/linux tags/v6.5/kernel.pid

for you to fetch changes up to 757777eef55b48b310603d0a1f6591f2a138691b:

  pid: Replace struct pid 1-element array with flex-array (2023-05-30 17:46:48 +0200)

Please consider pulling these changes from the signed v6.5/kernel.pid tag.

Thanks!
Christian

----------------------------------------------------------------
v6.5/kernel.pid

----------------------------------------------------------------
Kees Cook (1):
      pid: Replace struct pid 1-element array with flex-array

 include/linux/pid.h    |  2 +-
 kernel/pid.c           | 13 ++++++++-----
 kernel/pid_namespace.c |  2 +-
 3 files changed, 10 insertions(+), 7 deletions(-)