From: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
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@xxxxxx>
Cc: 6.3+ <stable@xxxxxxxxxx> # 6.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
