cmd: check argc for acpi dump

'acpi dump' without parameter results in a NULL dereference. Check the
number of arguments.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/cmd/acpi.c b/cmd/acpi.c
index 89970417a0285461738ed2def5baa131d16c0b0e..0c144092420eae705aa1f2fc932df6418215901c 100644 (file)
--- a/cmd/acpi.c
+++ b/cmd/acpi.c
@@ -160,6 +160,9 @@ static int do_acpi_dump(struct cmd_tbl *cmdtp, int flag, int argc,
        char sig[ACPI_NAME_LEN];
        int ret;
 
+       if (argc < 2)
+               return CMD_RET_USAGE;
+
        name = argv[1];
        if (strlen(name) != ACPI_NAME_LEN) {
                printf("Table name '%s' must be four characters\n", name);