[PATCH v1 1/2] parport: Clean up resources correctly when parport_register_port() fails

From: Andy Shevchenko
Date: Wed Oct 18 2023 - 10:59:33 EST


The smatch warns about uncleaned resources in case the
parport_register_port() fails:

parport_register_port() warn: '&tmp->full_list' not removed from list

This is indeed an issue introduced when converting code to use
kasprintf(). However, the whole kasprintf() dance in this case
is not needed as dev_set_name() can handle the formatted input
and produces the same result. So, the solution is to delegate
name forming to the dev_set_name() and make device_register()
error path to deal with error handling (via put_device() call).

Fixes: 8d8ae17eb0de ("parport: Use kasprintf() instead of fixed buffer formatting")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/r/202310180809.hepZB9k6-lkp@xxxxxxxxx/
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/parport/share.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index a9a9cb0477ea..048a459ce4b0 100644
--- a/drivers/parport/share.c
+++ b/drivers/parport/share.c
@@ -361,7 +361,6 @@ static void free_port(struct device *dev)
kfree(port->probe_info[d].description);
}

- kfree(port->name);
kfree(port);
}

@@ -479,16 +478,13 @@ struct parport *parport_register_port(unsigned long base, int irq, int dma,
/*
* Now that the portnum is known finish doing the Init.
*/
- tmp->name = kasprintf(GFP_KERNEL, "parport%d", tmp->portnum);
- if (!tmp->name) {
- kfree(tmp);
- return NULL;
- }
- dev_set_name(&tmp->bus_dev, tmp->name);
+ dev_set_name(&tmp->bus_dev, "parport%d", tmp->portnum);
tmp->bus_dev.bus = &parport_bus_type;
tmp->bus_dev.release = free_port;
tmp->bus_dev.type = &parport_device_type;

+ tmp->name = dev_name(&tmp->bus_dev);
+
for (device = 0; device < 5; device++)
/* assume the worst */
tmp->probe_info[device].class = PARPORT_CLASS_LEGACY;
--
2.40.0.1.gaa8946217a0b