Hello Namjae Jeon,
The patch 74d7970febf7: "ksmbd: fix racy issue from using ->d_parent
and ->d_name" from Apr 21, 2023, leads to the following Smatch static
checker warning:
fs/ksmbd/vfs.c:1159 ksmbd_vfs_kern_path_locked()
info: return a literal instead of 'err'
fs/ksmbd/vfs.c
1149 int ksmbd_vfs_kern_path_locked(struct ksmbd_work *work, char *name,
1150 unsigned int flags, struct path *path,
1151 bool caseless)
1152 {
1153 struct ksmbd_share_config *share_conf = work->tcon->share_conf;
1154 int err;
1155 struct path parent_path;
1156
1157 err = ksmbd_vfs_path_lookup_locked(share_conf, name, flags, path);
1158 if (!err)
--> 1159 return err;
Originally this was return 0, but the patch changed it to return ret.
The reason for this check is that sometimes people accidentally reverse
their if statements so they write if (!err) instead of if (err). Here
it looks intentional but it's hard to be sure.
1160
1161 if (caseless) {
1162 char *filepath;
1163 size_t path_len, remain_len;
1164
1165 filepath = kstrdup(name, GFP_KERNEL);
1166 if (!filepath)
1167 return -ENOMEM;
1168
1169 path_len = strlen(filepath);
1170 remain_len = path_len;
1171
1172 parent_path = share_conf->vfs_path;
1173 path_get(&parent_path);
1174
1175 while (d_can_lookup(parent_path.dentry)) {
1176 char *filename = filepath + path_len - remain_len;
1177 char *next = strchrnul(filename, '/');
1178 size_t filename_len = next - filename;
1179 bool is_last = !next[0];
1180
1181 if (filename_len == 0)
1182 break;
1183
1184 err = ksmbd_vfs_lookup_in_dir(&parent_path, filename,
1185 filename_len,
1186 work->conn->um);
1187 if (err)
1188 goto out2;
1189
1190 next[0] = '\0';
1191
1192 err = vfs_path_lookup(share_conf->vfs_path.dentry,
1193 share_conf->vfs_path.mnt,
1194 filepath,
1195 flags,
1196 path);
1197 if (err)
1198 goto out2;
1199 else if (is_last)
1200 goto out1;
1201 path_put(&parent_path);
1202 parent_path = *path;
1203
1204 next[0] = '/';
1205 remain_len -= filename_len + 1;
1206 }
1207
1208 err = -EINVAL;
1209 out2:
1210 path_put(&parent_path);
1211 out1:
1212 kfree(filepath);
1213 }
1214
1215 if (!err) {
1216 err = ksmbd_vfs_lock_parent(parent_path.dentry, path->dentry);
1217 if (err)
1218 dput(path->dentry);
1219 path_put(&parent_path);
1220 }
1221 return err;
1222 }
regards,
dan carpenter
