[PATCH 2/2] sha1-name: check for overflow of N in "foo^N" and "foo~N"
- From
René Scharfe <l.s.r@web.de>
- Date
- Sep 15, 2019, 12:10 UTC
- Message-ID
- <2be6e3ee-209e-9cd1-eb43-284f9a8462b3@web.de>
- In-Reply-To
- <c43610f2-a51f-7333-a200-a76930a0b705@web.de>
Reject values that don't fit into an int, as get_parent() and get_nth_ancestor() cannot handle them. That's better than potentially returning a random object.
If this restriction turns out to be too tight then we can switch to a wider data type, but we'd still have to check for overflow.
Signed-off-by: René Scharfe <l.s.r@web.de> --- sha1-name.c | 15 ++++++++++++--- t/t1506-rev-parse-diagnosis.sh | 4 ++-- 2 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/sha1-name.c b/sha1-name.c index c665e3f96d..7a047e9e2b 100644 --- a/sha1-name.c +++ b/sha1-name.c @@ -1160,13 +1160,22 @@ static enum get_oid_result get_oid_1(struct repository *r, } if (has_suffix) { - int num = 0; + unsigned int num = 0; int len1 = cp - name; cp++; - while (cp < name + len) - num = num * 10 + *cp++ - '0'; + while (cp < name + len) { + unsigned int digit = *cp++ - '0'; + if (unsigned_mult_overflows(num, 10)) + return MISSING_OBJECT; + num *= 10; + if (unsigned_add_overflows(num, digit)) + return MISSING_OBJECT; + num += digit; + } if (!num && len1 == len - 1) num = 1; + else if (num > INT_MAX) + return MISSING_OBJECT; if (has_suffix == '^') return get_parent(r, name, len1, oid, num); /* else if (has_suffix == '~') -- goes without saying */ diff --git a/t/t1506-rev-parse-diagnosis.sh b/t/t1506-rev-parse-diagnosis.sh index 5c4df47401..6a938b205b 100755 --- a/t/t1506-rev-parse-diagnosis.sh +++ b/t/t1506-rev-parse-diagnosis.sh @@ -215,11 +215,11 @@ test_expect_success 'arg before dashdash must be a revision (ambiguous)' ' test_cmp expect actual ' -test_expect_failure 'reject Nth parent if N is too high' ' +test_expect_success 'reject Nth parent if N is too high' ' test_must_fail git rev-parse HEAD^100000000000000000000000000000000 ' -test_expect_failure 'reject Nth ancestor if N is too high' ' +test_expect_success 'reject Nth ancestor if N is too high' ' test_must_fail git rev-parse HEAD~100000000000000000000000000000000 ' -- 2.23.0