[PATCH] cmd: ini: avoid NULL deref when loadaddr/filesize env vars are unset

[Naveen Kumar Chaudhary]

When the user runs "ini <section>" without explicit address or size
arguments, do_ini() falls back to env_get("loadaddr") and
env_get("filesize") and passes the results straight to hextoul().
env_get() returns NULL for an undefined variable and hextoul() does
not tolerate a NULL pointer, so on a board without these variables
set the command dereferences NULL.

Fetch the strings into locals first, reject the NULL case with
CMD_RET_USAGE, and only then convert to numeric values.

Fixes: c167cc02033 ("Add a new "ini" command")
Signed-off-by: Naveen Kumar Chaudhary <naveen.os...@gmail.com>
---
 cmd/ini.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/cmd/ini.c b/cmd/ini.c
index 96399017691..3fe86209c32 100644
--- a/cmd/ini.c
+++ b/cmd/ini.c
@@ -229,6 +229,7 @@ static int ini_handler(void *user, char *section, char 
*name, char *value)
 static int do_ini(struct cmd_tbl *cmdtp, int flag, int argc, char *const 
argv[])
 {
        const char *section;
+       const char *addr_str, *size_str;
        char *file_address;
        size_t file_size;
 
@@ -236,10 +237,16 @@ static int do_ini(struct cmd_tbl *cmdtp, int flag, int 
argc, char *const argv[])
                return CMD_RET_USAGE;
 
        section = argv[1];
-       file_address = (char *)hextoul(argc < 3 ? env_get("loadaddr") : argv[2],
-                                       NULL);
-       file_size = (size_t)hextoul(argc < 4 ? env_get("filesize") : argv[3],
-                                    NULL);
+       addr_str = argc < 3 ? env_get("loadaddr") : argv[2];
+       size_str = argc < 4 ? env_get("filesize") : argv[3];
+
+       if (!addr_str || !size_str) {
+               printf("ini: loadaddr/filesize not set\n");
+               return CMD_RET_USAGE;
+       }
+
+       file_address = (char *)hextoul(addr_str, NULL);
+       file_size = (size_t)hextoul(size_str, NULL);
 
        return ini_parse(file_address, file_size, ini_handler, (void *)section);
 }
-- 
2.43.0