`comedi_auto_config()` uses `dev->class_dev` for logging a kernel
message after releasing `dev->mutex`. There is an unlikely possibility
that the Comedi device `dev` will have been removed by the
`COMEDI_DEVCONFIG` ioctl() command. Keep hold of the mutex until the
kernel message has been sent to prevent that. The function can call
`comedi_release_hardware_device()` on error. In that case, the mutex
must be unlocked before that.
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/drivers.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 5a32b8fc000e..b7b9e48d4303 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -1059,12 +1059,12 @@ int comedi_auto_config(struct device *hardware_device,
ret = driver->auto_attach(dev, context);
if (ret >= 0)
ret = comedi_device_postconfig(dev);
- mutex_unlock(&dev->mutex);
if (ret < 0) {
dev_warn(hardware_device,
"driver '%s' failed to auto-configure device.\n",
driver->driver_name);
+ mutex_unlock(&dev->mutex);
comedi_release_hardware_device(hardware_device);
} else {
/*
@@ -1074,6 +1074,7 @@ int comedi_auto_config(struct device *hardware_device,
dev_info(dev->class_dev,
"driver '%s' has successfully auto-configured '%s'.\n",
driver->driver_name, dev->board_name);
+ mutex_unlock(&dev->mutex);
}
return ret;
}
--
2.20.1
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