Re: [PATCH v3 1/1] report binder txn errors via generic netlink

[Dan Carpenter <dan.carpenter@linaro.org>]

Hi Li,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Li-Li/report-binder-txn-errors-via-generic-netlink/20241022-032903
base:   staging/staging-testing
patch link:    https://lore.kernel.org/r/20241021182821.1259487-3-dualli%40chromium.org
patch subject: [PATCH v3 1/1] report binder txn errors via generic netlink
config: x86_64-randconfig-161-20241024 (https://download.01.org/0day-ci/archive/20241026/202410260847.NDByoPQo-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202410260847.NDByoPQo-lkp@intel.com/

New smatch warnings:
drivers/android/binder.c:7204 init_binder_device() warn: '&binder_device->miscdev' from misc_register() not released on lines: 7204.

vim +7204 drivers/android/binder.c

ac4812c5ffbb88 Martijn Coenen    2017-02-03  7173  static int __init init_binder_device(const char *name)
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7174  {
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7175  	int ret;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7176  	struct binder_device *binder_device;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7177  
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7178  	binder_device = kzalloc(sizeof(*binder_device), GFP_KERNEL);
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7179  	if (!binder_device)
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7180  		return -ENOMEM;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7181  
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7182  	binder_device->miscdev.fops = &binder_fops;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7183  	binder_device->miscdev.minor = MISC_DYNAMIC_MINOR;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7184  	binder_device->miscdev.name = name;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7185  
f0fe2c0f050d31 Christian Brauner 2020-03-03  7186  	refcount_set(&binder_device->ref, 1);
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7187  	binder_device->context.binder_context_mgr_uid = INVALID_UID;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7188  	binder_device->context.name = name;
c44b1231ff1170 Todd Kjos         2017-06-29  7189  	mutex_init(&binder_device->context.context_mgr_node_lock);
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7190  
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7191  	ret = misc_register(&binder_device->miscdev);
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7192  	if (ret < 0) {
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7193  		kfree(binder_device);
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7194  		return ret;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7195  	}
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7196  
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7197  	hlist_add_head(&binder_device->hlist, &binder_devices);
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7198  
39854ac9458c74 Li Li             2024-10-21  7199  	binder_device->context.report_seq = (atomic_t)ATOMIC_INIT(0);
39854ac9458c74 Li Li             2024-10-21  7200  	ret = binder_genl_init(&binder_device->context.genl_family, name);
39854ac9458c74 Li Li             2024-10-21  7201  	if (ret < 0)

Needs a misc_unregister() as well to prevent a use after free.

39854ac9458c74 Li Li             2024-10-21  7202  		kfree(binder_device);
39854ac9458c74 Li Li             2024-10-21  7203  
ac4812c5ffbb88 Martijn Coenen    2017-02-03 @7204  	return ret;
ac4812c5ffbb88 Martijn Coenen    2017-02-03  7205  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki