Re: [PATCH 1/3] git_parse_unsigned: reject negative values
From: Junio C Hamano <hidden>
Date: 2022-10-21 18:09:26
"Phillip Wood via GitGitGadget" [off-list ref] writes:
From: Phillip Wood <redacted> 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.
And the code now would reject something like "43-21" because it does not insist that "-" must be used for a sign, so it makes EINVAL doubly appropriate, I would think. In the original code, "43-21" would have been parsed as "43" (by strtoumax) followed by "-" (which is rejected by get_unit_factor() and yielded EINVAL, so this change would not change the behaviour for such an input, if we receive EINVAL when we see a "-". A devil's advocate would consider if we ever want to have a unit factor that has "-" in it (e.g. "10000e-3" == 10). I can buy it if we want to declare that it is not worth supporting.
quoted hunk
Signed-off-by: Phillip Wood <redacted> --- 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)