cpufreq: intel_pstate: Fix object lifecycle issue in update_qos_request()

Browse source

commit 69e5d50fcf upstream.

The cpufreq_cpu_put() call in update_qos_request() takes place too early
because the latter subsequently calls freq_qos_update_request() that
indirectly accesses the policy object in question through the QoS request
object passed to it.

Fortunately, update_qos_request() is called under intel_pstate_driver_lock,
so this issue does not matter for changing the intel_pstate operation
mode, but it theoretically can cause a crash to occur on CPU device hot
removal (which currently can only happen in virt, but it is formally
supported nevertheless).

Address this issue by modifying update_qos_request() to drop the
reference to the policy later.

Fixes: da5c504c7a ("cpufreq: intel_pstate: Implement QoS supported freq constraints")
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Link: https://patch.msgid.link/2255671.irdbgypaU6@rafael.j.wysocki
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Rafael J. Wysocki 2025-09-05 15:52:03 +02:00 • committed by Greg Kroah-Hartman

parent 83b594504d

commit ad4e8f9bdb

1 changed files with 5 additions and 3 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

8

drivers/cpufreq/intel_pstate.c

View file