drivers/ata/pata_parport/pata_parport.c:446 pi_init_one() warn: possible memory leak of 'pi'

From: Dan Carpenter
Date: Sat Mar 11 2023 - 07:36:19 EST

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: ef5f68cc1f829b492b19cd4df5af4454aa816b93
commit: 72f2b0b2185099dce354c805009f591dda3ab73d drivers/block: Move PARIDE protocol modules to drivers/ata/pata_parport
config: ia64-randconfig-m041-20230308 (https://download.01.org/0day-ci/archive/20230311/202303111822.IHNchbkp-lkp@xxxxxxxxx/config)
compiler: ia64-linux-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Reported-by: Dan Carpenter <error27@xxxxxxxxx>
| Link: https://lore.kernel.org/r/202303111822.IHNchbkp-lkp@xxxxxxxxx/

New smatch warnings:
drivers/ata/pata_parport/pata_parport.c:446 pi_init_one() warn: possible memory leak of 'pi'
drivers/ata/pata_parport/comm.c:64 comm_read_regr() warn: inconsistent indenting
drivers/ata/pata_parport/comm.c:164 comm_write_block() warn: inconsistent indenting

Old smatch warnings:
drivers/ata/pata_parport/pata_parport.c:445 pi_init_one() warn: unsigned 'pi->dev.id' is never less than zero.
drivers/ata/pata_parport/comm.c:168 comm_write_block() warn: inconsistent indenting
drivers/ata/pata_parport/comm.c:172 comm_write_block() warn: inconsistent indenting

vim +/pi +446 drivers/ata/pata_parport/pata_parport.c

246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 418 static struct pi_adapter *pi_init_one(struct parport *parport,
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 419 struct pi_protocol *pr, int mode, int unit, int delay)
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 420 {
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 421 struct pardev_cb par_cb = { };
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 422 char scratch[512];
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 423 const struct ata_port_info *ppi[] = { &pata_parport_port_info };
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 424 struct ata_host *host;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 425 struct pi_adapter *pi;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 426 struct pi_device_match match = { .parport = parport, .proto = pr };
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 427
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 428 /*
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 429 * Abort if there's a device already registered on the same parport
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 430 * using the same protocol.
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 431 */
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 432 if (bus_for_each_dev(&pata_parport_bus_type, NULL, &match, pi_find_dev))
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 433 return NULL;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 434
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 435 pi = kzalloc(sizeof(struct pi_adapter), GFP_KERNEL);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 436 if (!pi)
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 437 return NULL;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 438
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 439 /* set up pi->dev before pi_probe_unit() so it can use dev_printk() */
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 440 pi->dev.parent = &pata_parport_bus;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 441 pi->dev.bus = &pata_parport_bus_type;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 442 pi->dev.driver = &pr->driver;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 443 pi->dev.release = pata_parport_dev_release;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 444 pi->dev.id = ida_alloc(&pata_parport_bus_dev_ids, GFP_KERNEL);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 445 if (pi->dev.id < 0)
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 @446 return NULL; /* pata_parport_dev_release will do kfree(pi) */

The comment says that pata_parport_dev_release() will free "pi" but
that's impossible because pi is a local variable and we haven't called
device_register().

246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 447 dev_set_name(&pi->dev, "pata_parport.%u", pi->dev.id);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 448 if (device_register(&pi->dev)) {
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 449 put_device(&pi->dev);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 450 goto out_ida_free;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 451 }
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 452
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 453 pi->proto = pr;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 454
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 455 if (!try_module_get(pi->proto->owner))
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 456 goto out_unreg_dev;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 457 if (pi->proto->init_proto && pi->proto->init_proto(pi) < 0)
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 458 goto out_module_put;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 459
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 460 pi->delay = (delay == -1) ? pi->proto->default_delay : delay;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 461 pi->mode = mode;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 462 pi->port = parport->base;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 463
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 464 par_cb.private = pi;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 465 pi->pardev = parport_register_dev_model(parport, DRV_NAME, &par_cb,
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 466 pi->dev.id);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 467 if (!pi->pardev)
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 468 goto out_module_put;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 469
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 470 if (!pi_probe_unit(pi, unit, scratch)) {
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 471 dev_info(&pi->dev, "Adapter not found\n");
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 472 goto out_unreg_parport;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 473 }
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 474
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 475 pi->proto->log_adapter(pi, scratch, 1);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 476
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 477 host = ata_host_alloc_pinfo(&pi->pardev->dev, ppi, 1);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 478 if (!host)
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 479 goto out_unreg_parport;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 480 dev_set_drvdata(&pi->dev, host);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 481 host->private_data = pi;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 482
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 483 ata_port_desc(host->ports[0], "port %s", pi->pardev->port->name);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 484 ata_port_desc(host->ports[0], "protocol %s", pi->proto->name);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 485
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 486 pi_connect(pi);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 487 if (ata_host_activate(host, 0, NULL, 0, &pata_parport_sht))
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 488 goto out_unreg_parport;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 489
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 490 return pi;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 491
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 492 out_unreg_parport:
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 493 pi_disconnect(pi);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 494 parport_unregister_device(pi->pardev);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 495 if (pi->proto->release_proto)
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 496 pi->proto->release_proto(pi);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 497 out_module_put:
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 498 module_put(pi->proto->owner);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 499 out_unreg_dev:
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 500 device_unregister(&pi->dev);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 501 out_ida_free:
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 502 ida_free(&pata_parport_bus_dev_ids, pi->dev.id);
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 503 return NULL;
246a1c4c6b7ffb drivers/ata/pata_parport.c Ondrej Zary 2023-01-23 504 }

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