Re: [PATCH -next] thermal/drivers/thermal_hwmon: Fix a kernel NULL pointer dereference

From: Daniel Lezcano
Date: Wed Mar 29 2023 - 12:03:18 EST


On 29/03/2023 11:00, Zhang Rui wrote:
When the hwmon device node of a thermal zone device is not found,
using hwmon->device causes a kernel NULL pointer dereference.

Reported-by: Preble Adam C <adam.c.preble@xxxxxxxxx>
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>

Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>

---
Fixes: dec07d399cc8 ("thermal: Don't use 'device' internal thermal zone structure field")
dec07d399cc8 is a commit in the linux-next branch of linux-pm repo.
I'm not sure if the Fix tag applies to such commit or not.
---
drivers/thermal/thermal_hwmon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c
index c59db17dddd6..261743f461be 100644
--- a/drivers/thermal/thermal_hwmon.c
+++ b/drivers/thermal/thermal_hwmon.c
@@ -229,7 +229,7 @@ void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
hwmon = thermal_hwmon_lookup_by_type(tz);
if (unlikely(!hwmon)) {
/* Should never happen... */
- dev_dbg(hwmon->device, "hwmon device lookup failed!\n");
+ dev_dbg(&tz->device, "hwmon device lookup failed!\n");
return;
}

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