Add checks for clusters bitmap entry.

diff --git a/libexfat/lookup.c b/libexfat/lookup.c
index c2f6811..e5607d4 100644 (file)
--- a/libexfat/lookup.c
+++ b/libexfat/lookup.c
@@ -43,6 +43,7 @@ int exfat_readdir(struct exfat* ef, struct exfat_node* node,
        const struct exfat_file_info* file_info;
        const struct exfat_file_name* file_name;
        const struct exfat_upcase* upcase;
+       const struct exfat_bitmap* bitmap;
        uint8_t continuations = 0;
        le16_t* namep = NULL;
 
@@ -158,6 +159,23 @@ int exfat_readdir(struct exfat* ef, struct exfat_node* node,
                        exfat_read_raw(ef->upcase, le64_to_cpu(upcase->size),
                                        exfat_c2o(ef, le32_to_cpu(upcase->start_cluster)), ef->fd);
                        break;
+
+               case EXFAT_ENTRY_BITMAP:
+                       bitmap = (const struct exfat_bitmap*) entry;
+                       if (CLUSTER_INVALID(le32_to_cpu(bitmap->start_cluster)))
+                       {
+                               exfat_error("invalid cluster in clusters bitmap");
+                               return -EIO;
+                       }
+                       if (le64_to_cpu(bitmap->size) !=
+                                       ((le32_to_cpu(ef->sb->cluster_count) + 7) / 8))
+                       {
+                               exfat_error("invalid bitmap size: %"PRIu64" (expected %u)",
+                                               le64_to_cpu(bitmap->size),
+                                               (le32_to_cpu(ef->sb->cluster_count) + 7) / 8);
+                               return -EIO;
+                       }
+                       break;
                }
 
                /* fetch the next cluster if needed */