[PATCH v2] pata_parport: fix possible memory leak

[Ondrej Zary]

When ida_alloc() fails, "pi" is not freed although the misleading
comment says otherwise.
Move the ida_alloc() call up so we really don't have to free it.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Link: https://lore.kernel.org/r/202303111822.IHNchbkp-lkp@xxxxxxxxx/
Signed-off-by: Ondrej Zary <linux@xxxxxxx>
---
 drivers/ata/pata_parport/pata_parport.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/ata/pata_parport/pata_parport.c b/drivers/ata/pata_parport/pata_parport.c
index 6165ee9aa7da..a9eff6003098 100644
--- a/drivers/ata/pata_parport/pata_parport.c
+++ b/drivers/ata/pata_parport/pata_parport.c
@@ -503,18 +503,19 @@ static struct pi_adapter *pi_init_one(struct parport *parport,
 	if (bus_for_each_dev(&pata_parport_bus_type, NULL, &match, pi_find_dev))
 		return NULL;
 
+	id = ida_alloc(&pata_parport_bus_dev_ids, GFP_KERNEL);
+	if (id < 0)
+		return NULL;
+
 	pi = kzalloc(sizeof(struct pi_adapter), GFP_KERNEL);
 	if (!pi)
-		return NULL;
+		goto out_ida_free;
 
 	/* set up pi->dev before pi_probe_unit() so it can use dev_printk() */
 	pi->dev.parent = &pata_parport_bus;
 	pi->dev.bus = &pata_parport_bus_type;
 	pi->dev.driver = &pr->driver;
 	pi->dev.release = pata_parport_dev_release;
-	id = ida_alloc(&pata_parport_bus_dev_ids, GFP_KERNEL);
-	if (id < 0)
-		return NULL; /* pata_parport_dev_release will do kfree(pi) */
 	pi->dev.id = id;
 	dev_set_name(&pi->dev, "pata_parport.%u", pi->dev.id);
 	if (device_register(&pi->dev)) {
@@ -571,7 +572,7 @@ static struct pi_adapter *pi_init_one(struct parport *parport,
 out_unreg_dev:
 	device_unregister(&pi->dev);
 out_ida_free:
-	ida_free(&pata_parport_bus_dev_ids, pi->dev.id);
+	ida_free(&pata_parport_bus_dev_ids, id);
 	return NULL;
 }
 
-- 
Ondrej Zary