merge-upstream/v6.18.41 from branch/tag: upstream/v6.18.41 into branch: cos-6.18

Changelog:
-------------------------------------------------------------

Greg Kroah-Hartman (1):
      Linux 6.18.41

Thomas Gleixner (2):
      posix-timers: Expand timer_[re]arm() callbacks with a boolean return value
      posix-cpu-timers: Prevent UAF caused by non-leader exec() race

BUG=b/541136746
TEST=tryjob, validation and K8s e2e
RELEASE_NOTE=Updated the Linux kernel to v6.18.41.

Change-Id: Icc5b2b56996e1968f1ffa82ab84116d5a015eae7
Signed-off-by: COS Kernel Merge Bot <cloud-image-merge-automation@prod.google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/176946
Reviewed-by: Kevin Berry <kpberry@google.com>
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>