From: Taylor Blau <me@ttaylorr.com>
To: git@vger.kernel.org
Cc: gitster@pobox.com, stolee@gmail.com, peff@peff.net
Subject: [PATCH 1/3] t/t5318: introduce failing 'git commit-graph write' tests
Date: Thu, 5 Sep 2019 18:04:53 -0400 [thread overview]
Message-ID: <042a8ba8b2a98c269f9cd1a8e88488b80d686f0d.1567720960.git.me@ttaylorr.com> (raw)
In-Reply-To: <cover.1567720960.git.me@ttaylorr.com>
When invoking 'git commit-graph' in a corrupt repository, one can cause
a segfault when ancestral commits are corrupt in one way or another.
This is due to two function calls in the 'commit-graph.c' code that may
return NULL, but are not checked for NULL-ness before dereferencing.
Before fixing the bug, introduce two failing tests that demonstrate the
problem. The first test corrupts an ancestral commit's parent to point
to a non-existent object. The second test instead corrupts an ancestral
tree by removing the 'tree' information entirely from the commit. Both
of these cases cause segfaults, each at different lines.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
t/t5318-commit-graph.sh | 43 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index ab3eccf0fa..c855f81930 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -585,4 +585,47 @@ test_expect_success 'get_commit_tree_in_graph works for non-the_repository' '
test_cmp expect actual
'
+test_expect_failure 'corrupt commit-graph write (broken parent)' '
+ rm -rf repo &&
+ git init repo &&
+ (
+ cd repo &&
+ empty="$(git mktree </dev/null)" &&
+ cat >broken <<-EOF &&
+ tree $empty
+ parent 0000000000000000000000000000000000000000
+ author whatever <whatever@example.com> 1234 -0000
+ committer whatever <whatever@example.com> 1234 -0000
+
+ broken commit
+ EOF
+ broken="$(git hash-object -w -t commit --literally broken)" &&
+ git commit-tree -p "$broken" -m "good commit" "$empty" >good &&
+ test_must_fail git commit-graph write --stdin-commits \
+ <good 2>test_err &&
+ test_i18ngrep "unable to parse commit" test_err
+ )
+'
+
+test_expect_failure 'corrupt commit-graph write (missing tree)' '
+ rm -rf repo &&
+ git init repo &&
+ (
+ cd repo &&
+ tree="$(git mktree </dev/null)" &&
+ cat >broken <<-EOF &&
+ parent 0000000000000000000000000000000000000000
+ author whatever <whatever@example.com> 1234 -0000
+ committer whatever <whatever@example.com> 1234 -0000
+
+ broken commit
+ EOF
+ broken="$(git hash-object -w -t commit --literally broken)" &&
+ git commit-tree -p "$broken" -m "good" "$tree" >good &&
+ test_must_fail git commit-graph write --stdin-commits \
+ <good 2>test_err &&
+ test_i18ngrep "unable to get tree for" test_err
+ )
+'
+
test_done
--
2.23.0
next prev parent reply other threads:[~2019-09-05 22:04 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 22:04 [PATCH 0/3] commit-graph: harden against various corruptions Taylor Blau
2019-09-05 22:04 ` Taylor Blau [this message]
2019-09-06 16:48 ` [PATCH 1/3] t/t5318: introduce failing 'git commit-graph write' tests Derrick Stolee
2019-09-05 22:04 ` [PATCH 2/3] commit-graph.c: handle commit parsing errors Taylor Blau
2019-09-05 22:04 ` [PATCH 3/3] commit-graph.c: handle corrupt/missing trees Taylor Blau
2019-09-06 6:19 ` Jeff King
2019-09-06 15:42 ` Taylor Blau
2019-09-06 17:34 ` Jeff King
2019-09-06 16:51 ` Derrick Stolee
2019-09-06 17:37 ` Jeff King
2019-09-06 16:57 ` Junio C Hamano
2019-09-06 17:11 ` Junio C Hamano
2019-09-06 17:30 ` Jeff King
2019-09-06 17:28 ` Jeff King
2019-09-09 17:55 ` Junio C Hamano
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