Hi Yan, 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/Yan-Zhen/sunrpc-Fix-error-checking-for-d_hash_and_lookup/20240828-124615 base: git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next patch link: https://lore.kernel.org/r/20240828044355.590260-1-yanzhen%40vivo.com patch subject: [PATCH v3] sunrpc: Fix error checking for d_hash_and_lookup() config: i386-randconfig-141-20240829 (https://download.01.org/0day-ci/archive/20240829/202408290616.Ke1JxTcE-lkp@xxxxxxxxx/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@xxxxxxxxx> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202408290616.Ke1JxTcE-lkp@xxxxxxxxx/ smatch warnings: net/sunrpc/rpc_pipe.c:1310 rpc_gssd_dummy_populate() warn: passing zero to 'ERR_CAST' vim +/ERR_CAST +1310 net/sunrpc/rpc_pipe.c 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1297 static struct dentry * 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1298 rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data) 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1299 { 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1300 int ret = 0; 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1301 struct dentry *gssd_dentry; 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1302 struct dentry *clnt_dentry = NULL; 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1303 struct dentry *pipe_dentry = NULL; 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1304 struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name, 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1305 strlen(files[RPCAUTH_gssd].name)); 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1306 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1307 /* We should never get this far if "gssd" doesn't exist */ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1308 gssd_dentry = d_hash_and_lookup(root, &q); cf4564e657c6275 Yan Zhen 2024-08-28 1309 if (IS_ERR_OR_NULL(gssd_dentry)) cf4564e657c6275 Yan Zhen 2024-08-28 @1310 return ERR_CAST(gssd_dentry); The callers are not expecting a NULL return from rpc_gssd_dummy_populate() so this will lead to a crash. The comments to d_hash_and_lookup() say it returns NULL if the file doesn't exist and the error pointers if the filename is invalid. Neither one should be possible here according to the comments on line 1307. So we're debating about how to handle impossible situations. 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1311 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1312 ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL); 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1313 if (ret) { 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1314 pipe_dentry = ERR_PTR(ret); 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1315 goto out; 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1316 } 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1317 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1318 q.name = gssd_dummy_clnt_dir[0].name; 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1319 q.len = strlen(gssd_dummy_clnt_dir[0].name); 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1320 clnt_dentry = d_hash_and_lookup(gssd_dentry, &q); cf4564e657c6275 Yan Zhen 2024-08-28 1321 if (IS_ERR_OR_NULL(clnt_dentry)) { b7ade38165ca000 Vasily Averin 2020-06-01 1322 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1); 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1323 pipe_dentry = ERR_PTR(-ENOENT); 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1324 goto out; 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1325 } 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1326 e2f0c83a9de331d Jeff Layton 2013-12-05 1327 ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL); e2f0c83a9de331d Jeff Layton 2013-12-05 1328 if (ret) { e2f0c83a9de331d Jeff Layton 2013-12-05 1329 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1); e2f0c83a9de331d Jeff Layton 2013-12-05 1330 pipe_dentry = ERR_PTR(ret); e2f0c83a9de331d Jeff Layton 2013-12-05 1331 goto out; e2f0c83a9de331d Jeff Layton 2013-12-05 1332 } e2f0c83a9de331d Jeff Layton 2013-12-05 1333 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1334 pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data); e2f0c83a9de331d Jeff Layton 2013-12-05 1335 if (IS_ERR(pipe_dentry)) { e2f0c83a9de331d Jeff Layton 2013-12-05 1336 __rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1); 3396f92f8be606e Jeff Layton 2013-12-05 1337 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1); e2f0c83a9de331d Jeff Layton 2013-12-05 1338 } 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1339 out: 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1340 dput(clnt_dentry); 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1341 dput(gssd_dentry); 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1342 return pipe_dentry; 4b9a445e3eeb8bd Jeff Layton 2013-11-14 1343 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
