[PATCH] cmd: nvedit: Validate argument count before use

[Vincent Stehlé]

On Wed, Dec 17, 2025 at 08:57:38PM +0100, Marek Vasut wrote:
> Avoid NULL pointer dereference in case 'env select' is invoked
> without parameters, check the arg count and make sure it is at
> least 2, otherwise print usage.
> 
> The crash is easy to trigger e.g. in sandbox:
> $ ./u-boot -Tc "env select"

Thanks Marek.

I confirm this patch does indeed fix the crash on sandbox.
The behaviour remains the same when selecting "nowhere".
Feel free to add (or not):

  Tested-by: Vincent Stehlé <vincent.stehle at arm.com>

Best regards,
Vincent.

> 
> Fixes: a97d22ebba23 ("cmd: env: add env select command")
> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
> ---
> Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> Cc: Patrick Delaunay <patrick.delaunay at st.com>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: Vincent Stehlé <vincent.stehle at arm.com>
> Cc: u-boot at lists.denx.de
> ---
>  cmd/nvedit.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/cmd/nvedit.c b/cmd/nvedit.c
> index 11c3cea882b..636bddee1be 100644
> --- a/cmd/nvedit.c
> +++ b/cmd/nvedit.c
> @@ -499,6 +499,9 @@ static int do_env_load(struct cmd_tbl *cmdtp, int flag, int argc,
>  static int do_env_select(struct cmd_tbl *cmdtp, int flag, int argc,
>  			 char *const argv[])
>  {
> +	if (argc < 2)
> +		return CMD_RET_USAGE;
> +
>  	return env_select(argv[1]) ? 1 : 0;
>  }
>  #endif
> -- 
> 2.51.0
>