Hello Neil Armstrong,
Commit 3c9b6fd74188 ("iio: magnetometer: add Allegro MicroSystems
ALS31300 3-D Linear Hall Effect driver") from Oct 30, 2024
(linux-next), leads to the following Smatch static checker warning:
drivers/iio/magnetometer/als31300.c:248 als31300_trigger_handler()
warn: check that 'scan.timestamp' doesn't leak information
drivers/iio/magnetometer/als31300.c
226 static irqreturn_t als31300_trigger_handler(int irq, void *p)
227 {
228 struct iio_poll_func *pf = p;
229 struct iio_dev *indio_dev = pf->indio_dev;
230 struct als31300_data *data = iio_priv(indio_dev);
231 struct {
232 u16 temperature;
233 s16 channels[3];
234 aligned_s64 timestamp;
235 } scan;
236 s16 x, y, z;
237 int ret;
238 u16 t;
239
240 ret = als31300_get_measure(data, &t, &x, &y, &z);
241 if (ret)
242 goto trigger_out;
243
244 scan.temperature = t;
245 scan.channels[0] = x;
246 scan.channels[1] = y;
247 scan.channels[2] = z;
--> 248 iio_push_to_buffers_with_timestamp(indio_dev, &scan,
249 pf->timestamp);
So I guess we had some CVEs recently with regards to
iio_push_to_buffers_with_timestamp() so this was added as a "must be
initialized" thing. The "aligned_s64 timestamp" struct member is
sometimes initialized in iio_push_to_buffers_with_timestamp() but not
always. So this seems like a valid static checker warning?
These are simple enoug to fix if we add a "scan = {};" initializer
but the IIO function is slightly new to me so I thought I would consult.
There was also one in trigger_handler().
drivers/media/pci/mgb4/mgb4_trigger.c:99 trigger_handler()
warn: check that 'scan' doesn't leak information (struct has a hole after 'data')
250
251 trigger_out:
252 iio_trigger_notify_done(indio_dev->trig);
253
254 return IRQ_HANDLED;
255 }
regards,
dan carpenter
