From: Srinivas Pandruvada srinivas.pandruvada@linux.intel.com
commit b5d68f84f4c62c78bc3d004911d80da5aa22df8b upstream.
If cur_state for the powerclamp cooling device is set to the default minimum state of 0, without setting first to cur_state > 0, this results in NULL pointer access.
This NULL pointer access happens in the powercap core idle-inject function idle_inject_set_duration() as there is no NULL check for idle_inject_device pointer. This pointer must be allocated by calling idle_inject_register() or idle_inject_register_full().
In the function powerclamp_set_cur_state(), idle_inject_device pointer is allocated only when the cur_state > 0. But setting 0 without changing to any other state, idle_inject_set_duration() will be called with a NULL idle_inject_device pointer.
To address this, just return from powerclamp_set_cur_state() if the current cooling device state is the same as the last one. Since the power-up default cooling device state is 0, changing the state to 0 again here will return without calling idle_inject_set_duration().
Signed-off-by: Srinivas Pandruvada srinivas.pandruvada@linux.intel.com Fixes: 8526eb7fc75a ("thermal: intel: powerclamp: Use powercap idle-inject feature") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=217386 Tested-by: Risto A. Paju teknohog@iki.fi Cc: 6.3+ stable@kernel.org # 6.3+ Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/thermal/intel/intel_powerclamp.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/thermal/intel/intel_powerclamp.c +++ b/drivers/thermal/intel/intel_powerclamp.c @@ -703,6 +703,10 @@ static int powerclamp_set_cur_state(stru
new_target_ratio = clamp(new_target_ratio, 0UL, (unsigned long) (max_idle - 1)); + + if (powerclamp_data.target_ratio == new_target_ratio) + goto exit_set; + if (!powerclamp_data.target_ratio && new_target_ratio > 0) { pr_info("Start idle injection to reduce power\n"); powerclamp_data.target_ratio = new_target_ratio;