Re: [PATCH v2] rev-parse: check lookup'ed commit references for NULL
- From
Todd Zullinger <tmz@pobox.com>
- Date
- May 24, 2018, 14:04 UTC
- Message-ID
- <20180524140454.GC26695@zaya.teonanacatl.net>
- In-Reply-To
- <20180524062733.5412-1-newren@gmail.com>
[Added Florian to Cc]
Elijah Newren wrote:
Show 12 quoted lines
> Commits 2122f8b963d4 ("rev-parse: Add support for the ^! and ^@ syntax",
> 2008-07-26) and 3dd4e7320d ("Teach rev-parse the ... syntax.", 2006-07-04)
> taught rev-parse new syntax, and used lookup_commit_reference() as part of
> their logic. Neither usage checked the returned commit to see if it was
> non-NULL before using it. Check for NULL and ensure an appropriate error
> is reported to the user.
>
> Reported by Florian Weimer and Todd Zullinger.
>
> Helped-by: Jeff King <peff@peff.net>
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---The output is now much more consistent with other invalid input. The only (minor) difference I noticed was when using the fff...fff form. With exactly 40 chars, rev-parse prints both refs separately and then the full input string before the "fatal:" error. I doubt it's terribly important.
# exactly 40 chars $ ./git-rev-parse ffffffffffffffffffffffffffffffffffffffff...ffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffff...ffffffffffffffffffffffffffffffffffffffff fatal: ambiguous argument 'ffffffffffffffffffffffffffffffffffffffff...ffffffffffffffffffffffffffffffffffffffff': unknown revision or path not in the working tree. Use '--' to separate paths from revisions, like this: 'git <command> [<revision>...] -- [<file>...]'
# not 40 chars $ ./git-rev-parse fffffffffffffffffffffffffffffffffffffff...fffffffffffffffffffffffffffffffffffffff fffffffffffffffffffffffffffffffffffffff...fffffffffffffffffffffffffffffffffffffff fatal: ambiguous argument 'fffffffffffffffffffffffffffffffffffffff...fffffffffffffffffffffffffffffffffffffff': unknown revision or path not in the working tree. Use '--' to separate paths from revisions, like this: 'git <command> [<revision>...] -- [<file>...]'
Show 5 quoted lines
> I would have used a Reported-by tag for Florian and Todd, but looking at > the bugzilla.redhat.com bug report doesn't show me Florian's email > address. I grepped through git logs and found two associated with that > name, but didn't know if they were still accurate, or were a different > Florian. So I just went with the sentence instead.
I added Florian to Cc, in case he wants to provide a preferred address. (The Red Hat Bugzilla only shows email addresses if you're logged in.)
Thanks Elijah and Peff.
Show 51 quoted lines
> builtin/rev-parse.c | 8 ++++++--
> t/t6101-rev-parse-parents.sh | 8 ++++++++
> 2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
> index a1e680b5e9..a0a0ace38d 100644
> --- a/builtin/rev-parse.c
> +++ b/builtin/rev-parse.c
> @@ -282,6 +282,10 @@ static int try_difference(const char *arg)
> struct commit *a, *b;
> a = lookup_commit_reference(&start_oid);
> b = lookup_commit_reference(&end_oid);
> + if (!a || !b) {
> + *dotdot = '.';
> + return 0;
> + }
> exclude = get_merge_bases(a, b);
> while (exclude) {
> struct commit *commit = pop_commit(&exclude);
> @@ -328,12 +332,12 @@ static int try_parent_shorthands(const char *arg)
> return 0;
>
> *dotdot = 0;
> - if (get_oid_committish(arg, &oid)) {
> + if (get_oid_committish(arg, &oid) ||
> + !(commit = lookup_commit_reference(&oid))) {
> *dotdot = '^';
> return 0;
> }
>
> - commit = lookup_commit_reference(&oid);
> if (exclude_parent &&
> exclude_parent > commit_list_count(commit->parents)) {
> *dotdot = '^';
> diff --git a/t/t6101-rev-parse-parents.sh b/t/t6101-rev-parse-parents.sh
> index 8c617981a3..7683e4a114 100755
> --- a/t/t6101-rev-parse-parents.sh
> +++ b/t/t6101-rev-parse-parents.sh
> @@ -214,4 +214,12 @@ test_expect_success 'rev-list merge^-1x (garbage after ^-1)' '
> test_must_fail git rev-list merge^-1x
> '
>
> +test_expect_success 'rev-parse $garbage^@ does not segfault' '
> + test_must_fail git rev-parse $EMPTY_TREE^@
> +'
> +
> +test_expect_success 'rev-parse $garbage...$garbage does not segfault' '
> + test_must_fail git rev-parse $EMPTY_TREE...$EMPTY_BLOB
> +'
> +
> test_done--
Todd
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If the triangles were to make a God they would give him three sides.
-- Montesquieu