[bug report] iwlwifi: ACPI: support revision 3 WGDS tables

[bug report] iwlwifi: ACPI: support revision 3 WGDS tables

[Dan Carpenter]

Hello Ayala Barazani,

The patch 97f8a3d1610b: "iwlwifi: ACPI: support revision 3 WGDS
tables" from Oct 24, 2021, leads to the following Smatch static
checker warning:

	drivers/net/wireless/intel/iwlwifi/fw/acpi.c:801 iwl_sar_get_wgds_table()
	warn: duplicate check 'idx < (12 / 4 + (0))' (previous on line 749)

drivers/net/wireless/intel/iwlwifi/fw/acpi.c
   743  
   744          data = iwl_acpi_get_object(fwrt->dev, ACPI_WGDS_METHOD);
   745          if (IS_ERR(data))
   746                  return PTR_ERR(data);
   747  
   748          /* read the highest revision we understand first */
   749          for (idx = 0; idx < ARRAY_SIZE(rev_data); idx++) {
   750                  /* min_profiles != 0 requires num_profiles header */
   751                  u32 hdr_size = 1 + !!rev_data[idx].min_profiles;
   752                  u32 profile_size = ACPI_GEO_PER_CHAIN_SIZE *
   753                                     rev_data[idx].bands;
   754                  u32 max_size = hdr_size + profile_size * rev_data[idx].profiles;
   755                  u32 min_size;
   756  
   757                  if (!rev_data[idx].min_profiles)
   758                          min_size = max_size;
   759                  else
   760                          min_size = hdr_size +
   761                                     profile_size * rev_data[idx].min_profiles;
   762  
   763                  wifi_pkg = iwl_acpi_get_wifi_pkg_range(fwrt->dev, data,
   764                                                         min_size, max_size,
   765                                                         &tbl_rev);
   766                  if (!IS_ERR(wifi_pkg)) {

Should this break on error instead of a continue?

   767                          if (!(BIT(tbl_rev) & rev_data[idx].revisions))
   768                                  continue;
   769  
   770                          num_bands = rev_data[idx].bands;
   771                          num_profiles = rev_data[idx].profiles;
   772  
   773                          if (rev_data[idx].min_profiles) {
   774                                  /* read header that says # of profiles */
   775                                  union acpi_object *entry;
   776  
   777                                  entry = &wifi_pkg->package.elements[entry_idx];
   778                                  entry_idx++;
   779                                  if (entry->type != ACPI_TYPE_INTEGER ||
   780                                      entry->integer.value > num_profiles) {
   781                                          ret = -EINVAL;
   782                                          goto out_free;
   783                                  }
   784                                  num_profiles = entry->integer.value;
   785  
   786                                  /*
   787                                   * this also validates >= min_profiles since we
   788                                   * otherwise wouldn't have gotten the data when
   789                                   * looking up in ACPI
   790                                   */
   791                                  if (wifi_pkg->package.count !=
   792                                      min_size + profile_size * num_profiles) {
   793                                          ret = -EINVAL;
   794                                          goto out_free;
   795                                  }
   796                          }
   797                          goto read_table;
   798                  }
   799          }
   800  
   801          if (idx < ARRAY_SIZE(rev_data))
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^
idx is always == ARRAY_SIZE() at this point.


   802                  ret = PTR_ERR(wifi_pkg);
   803          else
   804                  ret = -ENOENT;
   805          goto out_free;
   806  
   807  read_table:
   808          fwrt->geo_rev = tbl_rev;
   809          for (i = 0; i < num_profiles; i++) {
   810                  for (j = 0; j < ACPI_GEO_NUM_BANDS_REV2; j++) {

regards,
dan carpenter