[PATCH 1/3] git_parse_unsigned: reject negative values

From: Phillip Wood via GitGitGadget <gitgitgadget@gmail.com>
Date: Oct 21, 2022, 13:45 UTC
Message-ID: <9c8440e5e82777311c6217cb4a9ddcd5cb8ce689.1666359915.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.1389.git.1666359915.gitgitgadget@gmail.com>

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.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
---
 config.c | 5 +++++
 1 file changed, 5 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)

-- 
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