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| author | Guenter Roeck <linux@roeck-us.net> | 2026-07-25 15:27:28 -0700 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2026-07-27 11:35:22 -0700 |
| commit | aa9429edf9fc0e90d6f4da19ea4b5495a54ab117 (patch) | |
| tree | c65c56b2d14b84dd1f1abc3c3ceb5a758ef5fe0d | |
| parent | f46d5ab43a572b84773015a76966f5da56fc1748 (diff) | |
| download | linux-next-aa9429edf9fc0e90d6f4da19ea4b5495a54ab117.tar.gz linux-next-aa9429edf9fc0e90d6f4da19ea4b5495a54ab117.zip | |
hwmon: (lm90) Only report alarms if driver is ready
Userspace can read sysfs attributes before driver registration is complete,
immediately after devm_hwmon_device_register_with_info() has been called.
At that time, data->hwmon_dev is not yet initialized. This can trigger
a NULL pointer access since lm90_update_device() and with it
lm90_update_alarms_locked() will be called. This call schedules
report_work and lm90_report_alarms(), which passes the still-NULL
data->hwmon_dev to hwmon_notify_event() and triggers a NULL pointer
dereference.
Fix the problem by only scheduling the report and alert workers
data->hwmon_dev is set.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: f6d0775119fb9 ("hwmon: (lm90) Rework alarm/status handling")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
| -rw-r--r-- | drivers/hwmon/lm90.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c index 4b9c0ccdf260..c6186505661f 100644 --- a/drivers/hwmon/lm90.c +++ b/drivers/hwmon/lm90.c @@ -1194,7 +1194,7 @@ static int lm90_update_alarms_locked(struct lm90_data *data, bool force) check_enable = (client->irq || !(data->config_orig & 0x80)) && (data->config & 0x80); - if (force || check_enable) + if (data->hwmon_dev && (force || check_enable)) schedule_work(&data->report_work); /* @@ -1202,7 +1202,7 @@ static int lm90_update_alarms_locked(struct lm90_data *data, bool force) * alarms are all clear, and alerts are currently disabled. * Otherwise (re)schedule worker if needed. */ - if (check_enable) { + if (check_enable && data->hwmon_dev) { if (!(data->current_alarms & data->alert_alarms)) { dev_dbg(&client->dev, "Re-enabling ALERT#\n"); lm90_update_confreg(data, data->config & ~0x80); |