Re: [PATCH v2 1/3] git_parse_unsigned: reject negative values
- From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
- Date
- Nov 9, 2022, 15:57 UTC
- Message-ID
- <221109.86pmdwp19z.gmgdl@evledraar.gmail.com>
- In-Reply-To
- <d1ac79909b9e777cae40a6a301e5cfd988c5f9d7.1668003388.git.gitgitgadget@gmail.com>
On Wed, Nov 09 2022, Phillip Wood via GitGitGadget wrote:
Show 39 quoted lines
> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> git_parse_unsigned() relies on strtoumax() which unfortunately parses
> negative values as large positive integers. Fix this by rejecting any
> string that contains '-' as we do in strtoul_ui(). I've chosen to treat
> negative numbers as invalid input and set errno to EINVAL rather than
> ERANGE one the basis that they are never acceptable if we're looking for
> a unsigned integer. This is also consistent with the existing behavior
> of rejecting "1–2" with EINVAL.
>
> As we do not have unit tests for this function it is tested indirectly
> by checking that negative values of reject for core.bigFileThreshold are
> rejected. As this function is also used by OPT_MAGNITUDE() a test is
> added to check that rejects negative values too.
>
> Helped-by: Jeff King <peff@peff.net>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---
> config.c | 5 +++++
> t/t0040-parse-options.sh | 5 +++++
> t/t1050-large.sh | 6 ++++++
> 3 files changed, 16 insertions(+)
>
> diff --git a/config.c b/config.c
> index cbb5a3bab74..d5069d4f01d 100644
> --- a/config.c
> +++ b/config.c
> @@ -1193,6 +1193,11 @@ static int git_parse_unsigned(const char *value, uintmax_t *ret, uintmax_t max)
> uintmax_t val;
> uintmax_t factor;
>
> + /* negative values would be accepted by strtoumax */
> + if (strchr(value, '-')) {
> + errno = EINVAL;
> + return 0;
> + }
> errno = 0;
> val = strtoumax(value, &end, 0);
> if (errno == ERANGE)There's nothing wrong with this, but since the topic here is "some issues I noticed" here's another one: We don't actually care if you set "errno = EINVAL" here in particular, just as long as it's not "ERANGE", anything else will do.
So, not worth a re-roll in itself, but maybe a prep patch (or follow-up) to do this would be nice? to make sure this errno handling is "reachable"?
diff --git a/config.c b/config.c index ff4ea29784b..33d05fde0ea 100644 --- a/config.c +++ b/config.c @@ -1260,9 +1260,12 @@ NORETURN static void die_bad_number(const char *name, const char *value) { const char *error_type = (errno == ERANGE) ? - N_("out of range") : N_("invalid unit"); + N_("out of range") : errno == EINVAL ? N_("invalid unit") : NULL; const char *bad_numeric = N_("bad numeric config value '%s' for '%s': %s"); + if (!error_type) + BUG("unhandled errno %d: %s", errno, strerror(errno)); + if (!value) value = "";