Subject: Re: [PATCH 2/2] gpg-interface: avoid buffer overrun in parse_ssh_output()

From: Junio C Hamano <[email-masked]>
Date: Sun, 31 Oct 2021 23:07:07 -0700

René Scharfe <[email-masked]> writes:

> If the string "key" we found in the output of ssh-keygen happens to be
> located at the very end of the line, then going four characters further
> leaves us beyond the end of the string.  Explicitly search for the
> space after "key" to handle a missing one gracefully.
>
> Signed-off-by: René Scharfe <[email-masked]>
> ---
> This code was added after v2.33.0.

Thanks.

Fabian, we are in -rc phase where we concentrate on fixing bugs in
the new code in 'master'.  A quick ack, "here is a better way to fix
it", or "no, that won't be needed because..." is very much
appreciated.

>  gpg-interface.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/gpg-interface.c b/gpg-interface.c
> index 62d340e78a..3838536f0a 100644
> --- a/gpg-interface.c
> +++ b/gpg-interface.c
> @@ -409,9 +409,9 @@ static void parse_ssh_output(struct signature_check *sigc)
>  		goto cleanup;
>  	}
>
> -	key = strstr(line, "key");
> +	key = strstr(line, "key ");
>  	if (key) {
> -		sigc->fingerprint = xstrdup(strstr(line, "key") + 4);
> +		sigc->fingerprint = xstrdup(strstr(line, "key ") + 4);
>  		sigc->key = xstrdup(sigc->fingerprint);
>  	} else {
>  		/*
> --
> 2.33.1