Re: [PATCH v2 1/3] keys, trusted: fix: *do not* allow duplicate key options

[Mimi Zohar <zohar@linux.vnet.ibm.com>]

On Sun, 2015-12-13 at 17:42 +0200, Jarkko Sakkinen wrote:
> The trusted keys option parsing allows specifying the same option
> multiple times. The last option value specified is used.
> 
> This can be seen as a regression because:
> 
> * No gain.
> * Could be problematic if there is be options dependent on other
>   options.

Thanks, Jarkko.   Although it should be obvious that patch limits the
number of times an option can be specified, you should explicitly
mention it in the patch description.

Mimi

> Reported-by: James Morris James Morris <jmorris@namei.org>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
>  security/keys/trusted.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/security/keys/trusted.c b/security/keys/trusted.c
> index 903dace..7c183c7 100644
> --- a/security/keys/trusted.c
> +++ b/security/keys/trusted.c
> @@ -736,11 +736,14 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
>  	int res;
>  	unsigned long handle;
>  	unsigned long lock;
> +	unsigned long token_mask = 0;
> 
>  	while ((p = strsep(&c, " \t"))) {
>  		if (*p == '\0' || *p == ' ' || *p == '\t')
>  			continue;
>  		token = match_token(p, key_tokens, args);
> +		if (test_and_set_bit(token, &token_mask))
> +			return -EINVAL;
> 
>  		switch (token) {
>  		case Opt_pcrinfo: