On 9/3/21 6:07 PM, David Collins wrote:
> On 9/3/21 5:34 PM, Subbaraman Narayanamurthy wrote:
>> of_parse_thermal_zones() parses the thermal-zones node and registers a
>> thermal_zone device for each subnode. However, if a thermal zone is
>> consuming a thermal sensor and that thermal sensor device hasn't probed
>> yet, an attempt to set trip_point_*_temp for that thermal zone device
>> can cause a NULL pointer dereference. Fix it.
>>
>> console:/sys/class/thermal/thermal_zone87 # echo 120000 > trip_point_0_temp
>> ...
>> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
>> ...
>> Call trace:
>> of_thermal_set_trip_temp+0x40/0xc4
>> trip_point_temp_store+0xc0/0x1dc
>> dev_attr_store+0x38/0x88
>> sysfs_kf_write+0x64/0xc0
>> kernfs_fop_write_iter+0x108/0x1d0
>> vfs_write+0x2f4/0x368
>> ksys_write+0x7c/0xec
>> __arm64_sys_write+0x20/0x30
>> el0_svc_common.llvm.7279915941325364641+0xbc/0x1bc
>> do_el0_svc+0x28/0xa0
>> el0_svc+0x14/0x24
>> el0_sync_handler+0x88/0xec
>> el0_sync+0x1c0/0x200
>>
>> Cc: stable@xxxxxxxxxxxxxxx
>> Suggested-by: David Collins <quic_collinsd@xxxxxxxxxxx>
>> Signed-off-by: Subbaraman Narayanamurthy <quic_subbaram@xxxxxxxxxxx>
>> ---
>> drivers/thermal/thermal_of.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
>> index 6379f26..ba53252 100644
>> --- a/drivers/thermal/thermal_of.c
>> +++ b/drivers/thermal/thermal_of.c
>> @@ -301,7 +301,7 @@ static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
>> if (trip >= data->ntrips || trip < 0)
>> return -EDOM;
>> - if (data->ops->set_trip_temp) {
>> + if (data->ops && data->ops->set_trip_temp) {
>> int ret;
>> ret = data->ops->set_trip_temp(data->sensor_data, trip, temp);
>>
>
> It looks like the same kind of data->ops null pointer dereference issue is present in three other functions within this file: of_thermal_get_temp(), of_thermal_set_emul_temp(), and of_thermal_get_trend(). Should those be fixed along with of_thermal_set_trip_temp() in a single patch?
Sure, I can make those changes in this patch itself.
>
> Thanks,
> David
