From 9d69789770155cc6573ed07862de3b28f0597a25 Mon Sep 17 00:00:00 2001 From: Darcy Burke Date: Tue, 25 Jun 2024 16:12:48 -0700 Subject: [PATCH] date: detect underflow/overflow when parsing dates with timezone offset Overriding the date of a commit to be close to "1970-01-01 00:00:00" with a large enough positive timezone for the equivelant GMT time to be before the epoch is considered valid by `parse_date_basic`. Similar behaviour occurs when using a date close to "2099-12-31 23:59:59" (the maximum date allowed by `tm_to_time_t`) with a large enough negative timezone offset. This leads to an integer underflow or underflow respectively in the commit timestamp, which is not caught by `git-commit`, but will cause other services to fail, such as `git-fsck`, which, for the first case, reports "badDateOverflow: invalid author/committer line - date causes integer overflow". Instead check the timezone offset and fail if the resulting time comes before the epoch "1970-01-01T00:00:00Z" or after the maximum date "2099-12-31T23:59:59Z". Using the REQUIRE_64BIT_TIME prerequisite, make sure that the tests near the end of Git time (aka end of year 2099) are not attempted on purely 32-bit systems, as they cannot express timestamp beyond 2038 anyway. Signed-off-by: Darcy Burke [jc: fixups for 32-bit platforms] Signed-off-by: Junio C Hamano --- date.c | 12 +++++++++++- t/t0006-date.sh | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 44 insertions(+), 1 deletion(-) diff --git a/date.c b/date.c index 7365a4ad24..bee9fe8f10 100644 --- a/date.c +++ b/date.c @@ -868,6 +868,10 @@ static int match_object_header_date(const char *date, timestamp_t *timestamp, in return 0; } + +/* timestamp of 2099-12-31T23:59:59Z, including 32 leap days */ +static const timestamp_t timestamp_max = (((timestamp_t)2100 - 1970) * 365 + 32) * 24 * 60 * 60 - 1; + /* Gr. strptime is crap for this; it doesn't have a way to require RFC2822 (i.e. English) day/month names, and it doesn't work correctly with %z. */ int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset) @@ -937,8 +941,14 @@ int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset) } } - if (!tm_gmt) + if (!tm_gmt) { + if (*offset > 0 && *offset * 60 > *timestamp) + return -1; + if (*offset < 0 && -*offset * 60 > timestamp_max - *timestamp) + return -1; *timestamp -= *offset * 60; + } + return 0; /* success */ } diff --git a/t/t0006-date.sh b/t/t0006-date.sh index 24e8647f26..fd373e1b39 100755 --- a/t/t0006-date.sh +++ b/t/t0006-date.sh @@ -123,6 +123,39 @@ check_parse '2008-02-14 20:30:45 -05:00' '2008-02-14 20:30:45 -0500' check_parse '2008-02-14 20:30:45' '2008-02-14 20:30:45 -0500' EST5 check_parse 'Thu, 7 Apr 2005 15:14:13 -0700' '2005-04-07 15:14:13 -0700' +check_parse '1970-01-01 00:00:00' '1970-01-01 00:00:00 +0000' +check_parse '1970-01-01 00:00:00 +00' '1970-01-01 00:00:00 +0000' +check_parse '1970-01-01 00:00:00 Z' '1970-01-01 00:00:00 +0000' +check_parse '1970-01-01 00:00:00 -01' '1970-01-01 00:00:00 -0100' +check_parse '1970-01-01 00:00:00 +01' bad +check_parse '1970-01-01 00:00:00 +11' bad +check_parse '1970-01-01 00:59:59 +01' bad +check_parse '1970-01-01 01:00:00 +01' '1970-01-01 01:00:00 +0100' +check_parse '1970-01-01 01:00:00 +11' bad +check_parse '1970-01-02 00:00:00 +11' '1970-01-02 00:00:00 +1100' +check_parse '1969-12-31 23:59:59' bad +check_parse '1969-12-31 23:59:59 +00' bad +check_parse '1969-12-31 23:59:59 Z' bad +check_parse '1969-12-31 23:59:59 +11' bad +check_parse '1969-12-31 23:59:59 -11' bad + +REQUIRE_64BIT_TIME=HAVE_64BIT_TIME +check_parse '2099-12-31 23:59:59' '2099-12-31 23:59:59 +0000' +check_parse '2099-12-31 23:59:59 +00' '2099-12-31 23:59:59 +0000' +check_parse '2099-12-31 23:59:59 Z' '2099-12-31 23:59:59 +0000' +check_parse '2099-12-31 23:59:59 +01' '2099-12-31 23:59:59 +0100' +check_parse '2099-12-31 23:59:59 -01' bad +check_parse '2099-12-31 23:59:59 -11' bad +check_parse '2099-12-31 23:00:00 -01' bad +check_parse '2099-12-31 22:59:59 -01' '2099-12-31 22:59:59 -0100' +check_parse '2100-00-00 00:00:00' bad +check_parse '2099-12-30 00:00:00 -11' '2099-12-30 00:00:00 -1100' +check_parse '2100-00-00 00:00:00 +00' bad +check_parse '2100-00-00 00:00:00 Z' bad +check_parse '2100-00-00 00:00:00 -11' bad +check_parse '2100-00-00 00:00:00 +11' bad +REQUIRE_64BIT_TIME= + check_approxidate() { echo "$1 -> $2 +0000" >expect test_expect_${3:-success} "parse approxidate ($1)" "