Re: [GIT PULL] hardening fixes for v6.16-rc1

[Kees Cook <kees@kernel.org>]

On Sun, Jun 01, 2025 at 10:40:18AM -0400, Konstantin Ryabitsev wrote:
> On Sun, Jun 01, 2025 at 12:42:14AM -0700, Kees Cook wrote:
> > Okay, reproducing the "b4 trailers" steps:
> > 
> > #### start from known good tree
> > $ git checkout 62329e859b25 -b test/wreckage/before
> > $ l
> > 62329e859b25 (HEAD -> test/wreckage/before, dev/v6.16-rc1-pre/-Wunterminated-string-initialization) [DUP]
> > 9a7d4e791037 crypto: Annotate crypto strings with nonstring
> > b080c44c4d69 kbuild: Re-enable -Wunterminated-string-initialization
> > 8c2bb7d12601 ubsan: integer-overflow: depend on BROKEN to keep this out of CI
> > b9dbd69a32e3 wifi: iwlwifi: mld: Work around Clang loop unrolling bug
> > 9d230d500b0e Merge tag 'driver-core-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
> > bf373e4c786b Merge tag 'devicetree-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
> > 8ca154e4910e Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
> > 43db11110730 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
> > 12e9b9e5223b Merge tag 'ipe-pr-20250527' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe
> > 90b83efa6701 (stable/master) Merge tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
> > 1b98f357dadd Merge tag 'net-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
> > ...
> > ### Try to update 8c2bb7d12601 with the Acked-by from the list...
> > $ b4 trailers -u https://lore.kernel.org/all/CANpmjNPpyJn++DVZmO89ms_HkJ0OvQzkps0GjCFbWkk0F+_8Xg@mail.gmail.com
> > Finding code-review trailers for 39 commits...
> 
> Yeah, this is danger territory, because you're asking to update a random
> commit in the tree history. Without passing --since, we're looking at raw git
> history in the current branch as far as 1 month back to try to figure out the
> range of commits that we should work with:

Yeah, my SSD glitches were a red-herring -- they happened before the
"known good state" sfr pointed out (so, yay, I did fix my trees from
that).

My mistakes were:

- not noticing the "39 commits" warning

- overriding my push sanity checks

Sorry about all the noise and confusion!

> https://git.kernel.org/pub/scm/utils/b4/b4.git/tree/src/b4/ez.py#n1048
> 
> I don't yet know why it wants to rewrite 39 commits when we're updating a
> commit that's only 3 away from the tip. If you manage to rerun this with b4 -d
> and send me the output, I will be glad to look at it. Alternatively, if you
> can let me know the steps to get my tree in the same state as yours, I can run
> it locally.

This shows the same problem (using Linus's tree and linux-next):

$ git checkout 9d230d500b0e -b test/repro/before
$ git cherry-pick 368556dd234d
$ git cherry-pick eef1355c269b
$ b4 trailers -u https://lore.kernel.org/all/CANpmjNPpyJn++DVZmO89ms_HkJ0OvQzkps0GjCFbWkk0F+_8Xg@mail.gmail.com

> Thanks for looking into this. Linus, this is accurate and I am 100% convinced
> that there was no malicious intent. My apologies for being part of the mess
> through the tooling.
> 
> I will reinstate Kees's account so he can resume his work.

Thank you! I will now *very carefully* construct a v2 PR...

-- 
Kees Cook