On 07/09/2021 21:01, 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
I'm still not convinced by the changes.
Could please tell the commit-id where this is happening and give the procedure to reproduce the bug ?
... 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
While at it, fix the possible NULL pointer dereference in other functions as well: of_thermal_get_temp(), of_thermal_set_emul_temp(), of_thermal_get_trend().
Cc: stable@vger.kernel.org Suggested-by: David Collins quic_collinsd@quicinc.com Signed-off-by: Subbaraman Narayanamurthy quic_subbaram@quicinc.com
Changes for v2:
- Added checks in of_thermal_get_temp(), of_thermal_set_emul_temp(), of_thermal_get_trend().
drivers/thermal/thermal_of.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c index 6379f26..9233f7e 100644 --- a/drivers/thermal/thermal_of.c +++ b/drivers/thermal/thermal_of.c @@ -89,7 +89,7 @@ static int of_thermal_get_temp(struct thermal_zone_device *tz, { struct __thermal_zone *data = tz->devdata;
- if (!data->ops->get_temp)
- if (!data->ops || !data->ops->get_temp) return -EINVAL;
return data->ops->get_temp(data->sensor_data, temp); @@ -186,6 +186,9 @@ static int of_thermal_set_emul_temp(struct thermal_zone_device *tz, { struct __thermal_zone *data = tz->devdata;
- if (!data->ops || !data->ops->set_emul_temp)
return -EINVAL;- return data->ops->set_emul_temp(data->sensor_data, temp);
} @@ -194,7 +197,7 @@ static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip, { struct __thermal_zone *data = tz->devdata;
- if (!data->ops->get_trend)
- if (!data->ops || !data->ops->get_trend) return -EINVAL;
return data->ops->get_trend(data->sensor_data, trip, trend); @@ -301,7 +304,7 @@ 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);