Re: [RFC v2 3/4] overlayfs: Optimize credentials usage

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20240125235723.39507-4-vinicius.gomes@intel.com>
References: <20240125235723.39507-4-vinicius.gomes@intel.com>
TO: Vinicius Costa Gomes <vinicius.gomes@intel.com>

Hi Vinicius,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on brauner-vfs/vfs.all]
[also build test WARNING on linus/master v6.8-rc1 next-20240125]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Vinicius-Costa-Gomes/cleanup-Fix-discarded-const-warning-when-defining-guards/20240126-080128
base:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git vfs.all
patch link:    https://lore.kernel.org/r/20240125235723.39507-4-vinicius.gomes%40intel.com
patch subject: [RFC v2 3/4] overlayfs: Optimize credentials usage
:::::: branch date: 2 days ago
:::::: commit date: 2 days ago
config: i386-randconfig-141-20240128 (https://download.01.org/0day-ci/archive/20240128/202401281540.6nl399om-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)

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 <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202401281540.6nl399om-lkp@intel.com/

New smatch warnings:
fs/overlayfs/readdir.c:990 ovl_check_empty_dir() error: uninitialized symbol 'err'.
fs/overlayfs/inode.c:506 ovl_set_or_remove_acl() error: uninitialized symbol 'real_acl'.
fs/overlayfs/xattrs.c:51 ovl_xattr_set() error: uninitialized symbol 'err'.
fs/overlayfs/xattrs.c:126 ovl_listxattr() error: uninitialized symbol 'res'.

Old smatch warnings:
fs/overlayfs/readdir.c:922 ovl_dir_fsync() warn: 'realfile' is an error pointer or valid
fs/overlayfs/inode.c:1221 ovl_get_inode() error: we previously assumed 'lowerpath' could be null (see line 1218)

vim +/err +990 fs/overlayfs/readdir.c

e9be9d5e76e348 Miklos Szeredi       2014-10-24   979  
e9be9d5e76e348 Miklos Szeredi       2014-10-24   980  int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
e9be9d5e76e348 Miklos Szeredi       2014-10-24   981  {
e9be9d5e76e348 Miklos Szeredi       2014-10-24   982  	int err;
95e598e7ace2d8 zhangyi (F           2017-10-31   983) 	struct ovl_cache_entry *p, *n;
4edb83bb1041e2 Miklos Szeredi       2017-07-27   984  	struct rb_root root = RB_ROOT;
6d0a8a90a5bbfd Amir Goldstein       2017-11-10   985  	const struct cred *old_cred;
e9be9d5e76e348 Miklos Szeredi       2014-10-24   986  
659396b09f494f Vinicius Costa Gomes 2024-01-25   987  	old_cred = ovl_creds(dentry->d_sb);
659396b09f494f Vinicius Costa Gomes 2024-01-25   988  	scoped_guard(cred, old_cred)
4edb83bb1041e2 Miklos Szeredi       2017-07-27   989  		err = ovl_dir_read_merged(dentry, list, &root);
e9be9d5e76e348 Miklos Szeredi       2014-10-24  @990  	if (err)
e9be9d5e76e348 Miklos Szeredi       2014-10-24   991  		return err;
e9be9d5e76e348 Miklos Szeredi       2014-10-24   992  
e9be9d5e76e348 Miklos Szeredi       2014-10-24   993  	err = 0;
e9be9d5e76e348 Miklos Szeredi       2014-10-24   994  
95e598e7ace2d8 zhangyi (F           2017-10-31   995) 	list_for_each_entry_safe(p, n, list, l_node) {
95e598e7ace2d8 zhangyi (F           2017-10-31   996) 		/*
95e598e7ace2d8 zhangyi (F           2017-10-31   997) 		 * Select whiteouts in upperdir, they should
95e598e7ace2d8 zhangyi (F           2017-10-31   998) 		 * be cleared when deleting this directory.
95e598e7ace2d8 zhangyi (F           2017-10-31   999) 		 */
95e598e7ace2d8 zhangyi (F           2017-10-31  1000) 		if (p->is_whiteout) {
95e598e7ace2d8 zhangyi (F           2017-10-31  1001) 			if (p->is_upper)
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1002  				continue;
95e598e7ace2d8 zhangyi (F           2017-10-31  1003) 			goto del_entry;
95e598e7ace2d8 zhangyi (F           2017-10-31  1004) 		}
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1005  
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1006  		if (p->name[0] == '.') {
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1007  			if (p->len == 1)
95e598e7ace2d8 zhangyi (F           2017-10-31  1008) 				goto del_entry;
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1009  			if (p->len == 2 && p->name[1] == '.')
95e598e7ace2d8 zhangyi (F           2017-10-31  1010) 				goto del_entry;
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1011  		}
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1012  		err = -ENOTEMPTY;
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1013  		break;
95e598e7ace2d8 zhangyi (F           2017-10-31  1014) 
95e598e7ace2d8 zhangyi (F           2017-10-31  1015) del_entry:
95e598e7ace2d8 zhangyi (F           2017-10-31  1016) 		list_del(&p->l_node);
95e598e7ace2d8 zhangyi (F           2017-10-31  1017) 		kfree(p);
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1018  	}
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1019  
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1020  	return err;
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1021  }
e9be9d5e76e348 Miklos Szeredi       2014-10-24  1022  

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