On Thu, Mar 11, 2021 at 4:19 AM JeongHyeon Lee <jhs2.lee@xxxxxxxxxxx> wrote:
>
> If there are multiple verity mode when parsing the verity mode of dm
> verity table, it will be set as the last one.
> So set to 'allow only once' to prevent it.
I agree that we shouldn't allow this, at least not without a warning,
but out of curiosity, do you actually have a situation where this
could happen? One ideally shouldn't be passing untrusted parameters to
dm-verity.
>
> Signed-off-by: JeongHyeon Lee <jhs2.lee@xxxxxxxxxxx>
> ---
> drivers/md/dm-verity-target.c | 38 ++++++++++++++++++++++++++---------
> 1 file changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
> index 808a98ef624c..b76431dc7721 100644
> --- a/drivers/md/dm-verity-target.c
> +++ b/drivers/md/dm-verity-target.c
> @@ -893,6 +893,28 @@ static int verity_alloc_zero_digest(struct dm_verity *v)
> return r;
> }
>
> +static inline bool verity_is_verity_mode(const char *arg_name)
> +{
> + return (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING) ||
> + !strcasecmp(arg_name, DM_VERITY_OPT_RESTART) ||
> + !strcasecmp(arg_name, DM_VERITY_OPT_PANIC));
> +}
> +
> +static int verity_parse_verity_mode(struct dm_verity *v, const char *arg_name)
> +{
> + if (v->mode)
> + return -EINVAL;
> +
> + if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING))
> + v->mode = DM_VERITY_MODE_LOGGING;
> + else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART))
> + v->mode = DM_VERITY_MODE_RESTART;
> + else if (!strcasecmp(arg_name, DM_VERITY_OPT_PANIC))
> + v->mode = DM_VERITY_MODE_PANIC;
> +
> + return 0;
> +}
> +
> static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
> struct dm_verity_sig_opts *verify_args)
> {
> @@ -916,16 +938,12 @@ static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
> arg_name = dm_shift_arg(as);
> argc--;
>
> - if (!strcasecmp(arg_name, DM_VERITY_OPT_LOGGING)) {
> - v->mode = DM_VERITY_MODE_LOGGING;
> - continue;
> -
> - } else if (!strcasecmp(arg_name, DM_VERITY_OPT_RESTART)) {
> - v->mode = DM_VERITY_MODE_RESTART;
> - continue;
> -
> - } else if (!strcasecmp(arg_name, DM_VERITY_OPT_PANIC)) {
> - v->mode = DM_VERITY_MODE_PANIC;
> + if (verity_is_verity_mode(arg_name)) {
> + r = verity_parse_verity_mode(v, arg_name);
> + if (r) {
> + ti->error = "Already verity mode set";
I don't have a strong opinion about this, but the documentation
doesn't talk about verity modes, so perhaps this could be reworded to
something like "Conflicting error handling parameters"?
> + return r;
> + }
> continue;
>
> } else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) {
> --
> 2.17.1
>
Sami
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/dm-devel
