Re: [U-Boot] [PATCH] cmd/gpt: Address error cases during gpt rename more correctly

[Simon Goldschmidt]

+ Jordy, who just found a bug here...

Am 08.11.2019 um 17:24 schrieb Tom Rini:
New analysis by the tool has shown that we have some cases where we
weren't handling the error exit condition correctly.  When we ran into
the ENOMEM case we wouldn't exit the function and thus incorrect things
could happen.  Rework the unwinding such that we don't need a helper
function now and free what we may have allocated.
Fixes: 18030d04d25d ("GPT: fix memory leaks identified by Coverity")
Reported-by: Coverity (CID: 275475, 275476)
Cc: Alison Chaiken <ali...@she-devel.com>
Signed-off-by: Tom Rini <tr...@konsulko.com>
---
  cmd/gpt.c | 35 ++++++++---------------------------
  1 file changed, 8 insertions(+), 27 deletions(-)

diff --git a/cmd/gpt.c b/cmd/gpt.c
index 0c4349f4b249..2da8df60dca3 100644
--- a/cmd/gpt.c
+++ b/cmd/gpt.c
@@ -633,21 +633,6 @@ static int do_disk_guid(struct blk_desc *dev_desc, char * 
const namestr)
  }
  
  #ifdef CONFIG_CMD_GPT_RENAME
-/*
- * There are 3 malloc() calls in set_gpt_info() and there is no info about 
which
- * failed.
- */
-static void set_gpt_cleanup(char **str_disk_guid,
-                           disk_partition_t **partitions)
-{
-#ifdef CONFIG_RANDOM_UUID
-       if (str_disk_guid)
-               free(str_disk_guid);
-#endif
-       if (partitions)
-               free(partitions);
-}
-
  static int do_rename_gpt_parts(struct blk_desc *dev_desc, char *subcomm,
                               char *name1, char *name2)
  {
@@ -699,11 +684,7 @@ static int do_rename_gpt_parts(struct blk_desc *dev_desc, 
char *subcomm,
                           &new_partitions, &part_count);
        if (ret < 0) {
                del_gpt_info();
-               free(partitions_list);
-               if (ret == -ENOMEM)
-                       set_gpt_cleanup(&str_disk_guid, &new_partitions);
-               else
-                       goto out;
+               goto out;
        }
  
  	if (!strcmp(subcomm, "swap")) {
@@ -768,11 +749,7 @@ static int do_rename_gpt_parts(struct blk_desc *dev_desc, 
char *subcomm,
         */
        if (ret < 0) {
                del_gpt_info();
-               free(partitions_list);
-               if (ret == -ENOMEM)
-                       set_gpt_cleanup(&str_disk_guid, &new_partitions);
-               else
-                       goto out;
+               goto out;
        }
  
  	debug("Writing new partition table\n");
@@ -797,8 +774,12 @@ static int do_rename_gpt_parts(struct blk_desc *dev_desc, 
char *subcomm,
        print_gpt_info();
        del_gpt_info();
   out:
-       free(new_partitions);
-       free(str_disk_guid);
+#ifdef CONFIG_RANDOM_UUID
+       if (str_disk_guid)

Looks good overall, but could it be required to initialize str_disk_guid 
and new_partitions to 0 to make this test here work? Because 
set_gpt_info does not always seem to set these pointers in the error 
case, so they could be left uninitialized?

Regards,
Simon

+               free(str_disk_guid);
+#endif
+       if (new_partitions)
+               free(new_partitions);
        free(partitions_list);
        return ret;
  }