LU-10772 utils: incorrect check in build_layout_from_yaml_node

In lustre/utils/lfs.c, build_layout_from_yaml_node(),
check and fail for NULL pointer 'string' before
dereferencing it.

Issue found in Static analysis.

Change-Id: I272432d3997f3bfae520ff3aa48d175309ccd386
Signed-off-by: Sonia Sharma <sonia.sharma@intel.com>
Reviewed-on: https://review.whamcloud.com/31537
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/utils/lfs.c b/lustre/utils/lfs.c
index e21b059..05e6f04 100644 (file)
--- a/lustre/utils/lfs.c
+++ b/lustre/utils/lfs.c
@@ -2255,59 +2255,64 @@ static int build_layout_from_yaml_node(struct cYAML *node,
        int rc = 0;
 
        while (node) {
-               string = node->cy_string;
-               /* skip leading lmm_ if present, to simplify parsing */
-               if (string != NULL && strncmp(string, "lmm_", 4) == 0)
-                       string += 4;
-
-               if (node->cy_type == CYAML_TYPE_STRING) {
-                       if (!strcmp(string, "lcme_extent.e_end")) {
-                               if (!strcmp(node->cy_valuestring, "EOF") ||
-                                   !strcmp(node->cy_valuestring, "eof"))
-                                       lsa->lsa_comp_end = LUSTRE_EOF;
-                       } else if (!strcmp(string, "pool")) {
-                               lsa->lsa_pool_name = node->cy_valuestring;
-                       } else if (!strcmp(string, "pattern")) {
-                               if (!strcmp(node->cy_valuestring, "mdt"))
-                                       lsa->lsa_pattern = LLAPI_LAYOUT_MDT;
-                       }
-               } else if (node->cy_type == CYAML_TYPE_NUMBER) {
-                       if (!strcmp(string, "lcm_mirror_count")) {
-                               lsa->lsa_mirror_count = node->cy_valueint;
-                       } else if (!strcmp(string, "lcme_extent.e_start")) {
-                               if (node->cy_valueint != 0 || *layout != NULL) {
-                                       rc = build_component(layout, lsa, true);
-                                       if (rc)
-                                               return rc;
-                               }
-
-                               if (node->cy_valueint == 0)
-                                       lsa->lsa_first_comp = true;
-
-                               /* initialize lsa */
-                               setstripe_args_init(lsa);
-                               lsa->lsa_tgts = osts;
-                       } else if (!strcmp(string, "lcme_extent.e_end")) {
-                               if (node->cy_valueint == -1)
-                                       lsa->lsa_comp_end = LUSTRE_EOF;
-                               else
-                                       lsa->lsa_comp_end = node->cy_valueint;
-                       } else if (!strcmp(string, "stripe_count")) {
-                               lsa->lsa_stripe_count = node->cy_valueint;
-                       } else if (!strcmp(string, "stripe_size")) {
-                               lsa->lsa_stripe_size = node->cy_valueint;
-                       } else if (!strcmp(string, "stripe_offset")) {
-                               lsa->lsa_stripe_off = node->cy_valueint;
-                       } else if (!strcmp(string, "l_ost_idx")) {
-                               osts[lsa->lsa_nr_tgts] = node->cy_valueint;
-                               lsa->lsa_nr_tgts++;
-                       }
-               } else if (node->cy_type == CYAML_TYPE_OBJECT) {
+               if (node->cy_type == CYAML_TYPE_OBJECT) {
                        /* go deep to sub blocks */
                        rc = build_layout_from_yaml_node(node->cy_child, layout,
                                                         lsa, osts);
                        if (rc)
                                return rc;
+               } else {
+                       if (node->cy_string == NULL)
+                               return -EINVAL;
+
+                       string = node->cy_string;
+                       /* skip leading lmm_ if present, to simplify parsing */
+                       if (strncmp(string, "lmm_", 4) == 0)
+                               string += 4;
+
+                       if (node->cy_type == CYAML_TYPE_STRING) {
+                               if (!strcmp(string, "lcme_extent.e_end")) {
+                                       if (!strcmp(node->cy_valuestring, "EOF") ||
+                                           !strcmp(node->cy_valuestring, "eof"))
+                                               lsa->lsa_comp_end = LUSTRE_EOF;
+                               } else if (!strcmp(string, "pool")) {
+                                       lsa->lsa_pool_name = node->cy_valuestring;
+                               } else if (!strcmp(string, "pattern")) {
+                                       if (!strcmp(node->cy_valuestring, "mdt"))
+                                               lsa->lsa_pattern = LLAPI_LAYOUT_MDT;
+                               }
+                       } else if (node->cy_type == CYAML_TYPE_NUMBER) {
+                               if (!strcmp(string, "lcm_mirror_count")) {
+                                       lsa->lsa_mirror_count = node->cy_valueint;
+                               } else if (!strcmp(string, "lcme_extent.e_start")) {
+                                       if (node->cy_valueint != 0 || *layout != NULL) {
+                                               rc = build_component(layout, lsa, true);
+                                               if (rc)
+                                                       return rc;
+                                       }
+
+                                       if (node->cy_valueint == 0)
+                                               lsa->lsa_first_comp = true;
+
+                                       /* initialize lsa */
+                                       setstripe_args_init(lsa);
+                                       lsa->lsa_tgts = osts;
+                               } else if (!strcmp(string, "lcme_extent.e_end")) {
+                                       if (node->cy_valueint == -1)
+                                               lsa->lsa_comp_end = LUSTRE_EOF;
+                                       else
+                                               lsa->lsa_comp_end = node->cy_valueint;
+                               } else if (!strcmp(string, "stripe_count")) {
+                                       lsa->lsa_stripe_count = node->cy_valueint;
+                               } else if (!strcmp(string, "stripe_size")) {
+                                       lsa->lsa_stripe_size = node->cy_valueint;
+                               } else if (!strcmp(string, "stripe_offset")) {
+                                       lsa->lsa_stripe_off = node->cy_valueint;
+                               } else if (!strcmp(string, "l_ost_idx")) {
+                                       osts[lsa->lsa_nr_tgts] = node->cy_valueint;
+                                       lsa->lsa_nr_tgts++;
+                               }
+                       }
                }
                node = node->cy_next;
        }