git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-core-2026-06-13

Updates for the time/timer core subsystem:

  - Harden the user space controllable hrtimer interfaces further to
    protect against unpriviledged DoS attempts by arming timers in the past.

  - Add per-capacity hierarchies to the timer migration code to prevent
    timer migration accross different capacity domains. This code has been
    disabled last minute as there is a pathological problem with SoCs which
    advertise a larger number of capacity domains. The problem is under
    investigation and the code won't be active before v7.3, but that turned
    out to be less intrusive than a full revert as it preserves the
    preparatory steps and allows people to work on the final resolution

  - Export time namespace functionality as a recent user can be built as a
    module.

  - Initialize the jiffies clocksource before using it. The recent
    hardening against time moving backward requires that the related
    members of struct clocksource have been initialized, otherwise it
    clamps the readout to 0, which makes time stand sill and causes boot
    delays.

  - Fix a more than twenty year old PID reference count leak in an error
    path of the POSIX CPU timer code.

  - The usual small fixes, improvements and cleanups all over the place.

posix-cpu-timers: Fix pid refcount leak in do_cpu_nanosleep() error path

In do_cpu_nanosleep(), posix_cpu_timer_create() takes a pid reference
via get_pid() and stores it in timer.it.cpu.pid. If the subsequent
posix_cpu_timer_set() call fails, the function returns immediately
without calling posix_cpu_timer_del() to release the pid reference,
causing a leak.

Fix it by calling posix_cpu_timer_del() before the unlock-and-return
on the error path, consistent with the other exit paths in the same
function.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260611161738.97043-1-vulab@iscas.ac.cn