From: darcy <acednes@xxxxxxxxx>
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`.
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".
Instead check the timezone offset and fail if the resulting time comes
before the epoch, "1970-01-01T00:00:00Z", when parsing.
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
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1726%2Fdxrcy%2Fmaster-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1726/dxrcy/master-v2
Pull-Request: https://github.com/git/git/pull/1726
Range-diff vs v1:
1: 4542d984aab ! 1: db508b2f533 fix: prevent date underflow when using positive timezone offset
@@ Metadata
Author: darcy <acednes@xxxxxxxxx>
## Commit message ##
- fix: prevent date underflow when using positive timezone offset
+ date: detect underflow when parsing dates with positive timezone offset
- Overriding the date of a commit to be `1970-01-01` with a large enough
- timezone for the equivalent GMT time to before 1970 is no longer
- accepted.
+ 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`.
- Example: `GIT_COMMITTER_DATE='1970-01-01T00:00:00+10' git commit` would
- previously be accepted, only to unexpectedly fail in other parts of the
- code, such as `git push`. The timestamp is now checked against postitive
- timezone values.
+ 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".
- Signed-off-by: darcy <acednes@xxxxxxxxx>
+ Instead check the timezone offset and fail if the resulting time comes
+ before the epoch, "1970-01-01T00:00:00Z", when parsing.
+
+ Signed-off-by: Darcy Burke <acednes@xxxxxxxxx>
## date.c ##
-@@ date.c: int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset)
- match = match_alpha(date, &tm, offset);
- else if (isdigit(c))
- match = match_digit(date, &tm, offset, &tm_gmt);
-- else if ((c == '-' || c == '+') && isdigit(date[1]))
-+ else if ((c == '-' || c == '+') && isdigit(date[1]) && tm.tm_hour != -1)
- match = match_tz(date, offset);
-
- if (!match) {
@@ date.c: int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset)
}
}
- if (!tm_gmt)
+ if (!tm_gmt) {
-+ if (*offset > 0 && *offset * 60 > *timestamp) {
++ if (*offset > 0 && *offset * 60 > *timestamp)
+ return -1;
-+ }
*timestamp -= *offset * 60;
+ }
+
return 0; /* success */
}
+
+ ## 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'
+ 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_approxidate() {
+ echo "$1 -> $2 +0000" >expect
date.c | 6 +++++-
t/t0006-date.sh | 15 +++++++++++++++
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/date.c b/date.c
index 7365a4ad24f..8e3ec1bcb00 100644
--- a/date.c
+++ b/date.c
@@ -937,8 +937,12 @@ 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;
*timestamp -= *offset * 60;
+ }
+
return 0; /* success */
}
diff --git a/t/t0006-date.sh b/t/t0006-date.sh
index 3031256d143..cdbb40bec01 100755
--- a/t/t0006-date.sh
+++ b/t/t0006-date.sh
@@ -116,6 +116,21 @@ 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'
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_approxidate() {
echo "$1 -> $2 +0000" >expect
base-commit: 9eaef5822cd76bbeb53b6479ce0ddaad34ee2b14
--
gitgitgadget
