Merge branch 'pw/config-int-parse-fixes'

Assorted fixes of parsing end-user input as integers.

* pw/config-int-parse-fixes:
  git_parse_signed(): avoid integer overflow
  config: require at least one digit when parsing numbers
  git_parse_unsigned: reject negative values

1 files changed, 19 insertions, 5 deletions

diff --git a/config.c b/config.c
index c058b2c..27f3828 100644
--- a/config.c
+++ b/config.c
@@ -1160,21 +1160,26 @@ static int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
 	if (value && *value) {
 		char *end;
 		intmax_t val;
-		uintmax_t uval;
-		uintmax_t factor;
+		intmax_t factor;
+
+		if (max < 0)
+			BUG("max must be a positive integer");
 
 		errno = 0;
 		val = strtoimax(value, &end, 0);
 		if (errno == ERANGE)
 			return 0;
+		if (end == value) {
+			errno = EINVAL;
+			return 0;
+		}
 		factor = get_unit_factor(end);
 		if (!factor) {
 			errno = EINVAL;
 			return 0;
 		}
-		uval = val < 0 ? -val : val;
-		if (unsigned_mult_overflows(factor, uval) ||
-		    factor * uval > max) {
+		if ((val < 0 && -max / factor > val) ||
+		    (val > 0 && max / factor < val)) {
 			errno = ERANGE;
 			return 0;
 		}
@@ -1193,10 +1198,19 @@ 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)
 			return 0;
+		if (end == value) {
+			errno = EINVAL;
+			return 0;
+		}
 		factor = get_unit_factor(end);
 		if (!factor) {
 			errno = EINVAL;