From: darcy <acednes@xxxxxxxxx>
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".
Signed-off-by: Darcy Burke <acednes@xxxxxxxxx>
---
fix: prevent date underflow when using positive timezone offset
cc: Patrick Steinhardt ps@xxxxxx cc: Phillip Wood
phillip.wood123@xxxxxxxxx cc: darcy acednes@xxxxxxxxx cc: Jeff King
peff@xxxxxxxx
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1726%2Fdxrcy%2Fmaster-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1726/dxrcy/master-v3
Pull-Request: https://github.com/git/git/pull/1726
Range-diff vs v2:
1: db508b2f533 ! 1: f0de3a2c543 date: detect underflow when parsing dates with positive timezone offset
@@ Metadata
Author: darcy <acednes@xxxxxxxxx>
## Commit message ##
- date: detect underflow when parsing dates with positive timezone offset
+ 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 timezone for the equivelant GMT time to be before
- the epoch is considered valid by `parse_date_basic`.
+ 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 in the commit timestamp, which is not
- caught by `git-commit`, but will cause other services to fail, such as
- `git-fsck`, which reports "badDateOverflow: invalid author/committer
- line - date causes integer overflow".
+ 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", when parsing.
+ before the epoch "1970-01-01T00:00:00Z" or after the maximum date
+ "2099-12-31T23:59:59Z".
Signed-off-by: Darcy Burke <acednes@xxxxxxxxx>
## date.c ##
+@@ date.c: 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 time_t timestamp_max = ((2100L - 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)
@@ date.c: int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset)
}
}
@@ date.c: int parse_date_basic(const char *date, timestamp_t *timestamp, int *offs
- 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;
+ }
@@ date.c: int parse_date_basic(const char *date, timestamp_t *timestamp, int *offs
## t/t0006-date.sh ##
-@@ t/t0006-date.sh: check_parse '2008-02-14 20:30:45 -:30' '2008-02-14 20:30:45 +0000'
- check_parse '2008-02-14 20:30:45 -05:00' '2008-02-14 20:30:45 -0500'
+@@ t/t0006-date.sh: 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'
@@ t/t0006-date.sh: check_parse '2008-02-14 20:30:45 -:30' '2008-02-14 20:30:45 +00
+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
-
++
++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
++
check_approxidate() {
echo "$1 -> $2 +0000" >expect
+ test_expect_${3:-success} "parse approxidate ($1)" "
date.c | 12 +++++++++++-
t/t0006-date.sh | 31 +++++++++++++++++++++++++++++++
2 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/date.c b/date.c
index 7365a4ad24f..95776c8a92f 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 time_t timestamp_max = ((2100L - 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 3031256d143..e8fdf361ad4 100755
--- a/t/t0006-date.sh
+++ b/t/t0006-date.sh
@@ -117,6 +117,37 @@ 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
+
+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
+
check_approxidate() {
echo "$1 -> $2 +0000" >expect
test_expect_${3:-success} "parse approxidate ($1)" "
base-commit: cd77e87115eab5e80e6b161e7b84a79ba1a12cdc
--
gitgitgadget
