[PATCH 03/10] rebase & sequencer API: fix get_replay_opts() leak in "rebase"

From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: git@vger.kernel.org
Cc: "Phillip Wood" <phillip.wood@dunelm.org.uk>,
	"Johannes Schindelin" <Johannes.Schindelin@gmx.de>,
	"Junio C Hamano" <gitster@pobox.com>,
	"Taylor Blau" <me@ttaylorr.com>, "René Scharfe" <l.s.r@web.de>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Subject: [PATCH 03/10] rebase & sequencer API: fix get_replay_opts() leak in "rebase"
Date: Fri, 30 Dec 2022 08:28:08 +0100	[thread overview]
Message-ID: <patch-03.10-3e9c4df61fe-20221230T071741Z-avarab@gmail.com> (raw)
In-Reply-To: <cover-00.10-00000000000-20221230T071741Z-avarab@gmail.com>

Make the recently added replay_opts_release() function non-static and
use it for freeing the "struct replay_opts" constructed by the
get_replay_opts() function in "builtin/rebase.c". See [1] for the
initial addition of get_replay_opts().

To safely call our new replay_opts_release() we'll need to change all
the free() to a FREE_AND_NULL(), and set "xopts_nr" to "0" after we
loop over it and free() it (the free() in the loop doesn't need to be
a FREE_AND_NULL()).

This is because in e.g. do_interactive_rebase() we construct a "struct
replay_opts" with "get_replay_opts()", and then call
"complete_action()". If we get far enough in that function without
encountering errors we'll call "pick_commits()" which (indirectly)
calls sequencer_remove_state() at the end.

But if we encounter errors anywhere along the way we'd punt out early,
and not free() the memory we allocated. Remembering whether we
previously called sequencer_remove_state() would be a hassle, so let's
make it safe to re-invoke replay_opts_release() instead.

I experimented with a change to be more paranoid instead, i.e. to
exhaustively check our state via an enum. We could make sure that we:

- Only allow calling "replay_opts_release()" after
  "sequencer_remove_state()", but not the other way around.

- Forbid invoking either function twice in a row.

But such paranoia isn't warranted here, let's instead take the easy
way out and FREE_AND_NULL() this.

See [2] for the initial implementation of "sequencer_remove_state()",
which assumed that it should be removing the full (including on-disk)
rebase state as a one-off.

1. 73fdc535d26 (rebase -i: use struct rebase_options to parse args,
   2019-04-17)
2. 26ae337be11 (revert: Introduce --reset to remove sequencer state,
   2011-08-04)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---

Re the "I experimented with...", the earlier version can be seen at
https://github.com/avar/git/commit/7a150d1b7e2; It's the commit I
linked to from
https://lore.kernel.org/git/221108.864jv9sc9r.gmgdl@evledraar.gmail.com/
(which is mentioned in the CL).

 builtin/rebase.c                       |  2 ++
 sequencer.c                            | 13 +++++++------
 sequencer.h                            |  1 +
 t/t3405-rebase-malformed.sh            |  1 +
 t/t3412-rebase-root.sh                 |  1 +
 t/t3423-rebase-reword.sh               |  1 +
 t/t3437-rebase-fixup-options.sh        |  1 +
 t/t3438-rebase-broken-files.sh         |  2 ++
 t/t7402-submodule-rebase.sh            |  1 +
 t/t9106-git-svn-commit-diff-clobber.sh |  1 -
 t/t9164-git-svn-dcommit-concurrent.sh  |  1 -
 11 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/builtin/rebase.c b/builtin/rebase.c
index 7141fd5e0c1..91bf55be6e6 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -301,6 +301,7 @@ static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 	}
 
 cleanup:
+	replay_opts_release(&replay);
 	string_list_clear(&commands, 0);
 	free(revisions);
 	free(shortrevisions);
@@ -343,6 +344,7 @@ static int run_sequencer_rebase(struct rebase_options *opts)
 		struct replay_opts replay_opts = get_replay_opts(opts);
 
 		ret = sequencer_continue(the_repository, &replay_opts);
+		replay_opts_release(&replay_opts);
 		break;
 	}
 	case ACTION_EDIT_TODO:
diff --git a/sequencer.c b/sequencer.c
index 655ae9f1a72..e29a97b6caa 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -351,15 +351,16 @@ static const char *gpg_sign_opt_quoted(struct replay_opts *opts)
 	return buf.buf;
 }
 
-static void replay_opts_release(struct replay_opts *opts)
+void replay_opts_release(struct replay_opts *opts)
 {
-	free(opts->gpg_sign);
-	free(opts->reflog_action);
-	free(opts->default_strategy);
-	free(opts->strategy);
+	FREE_AND_NULL(opts->gpg_sign);
+	FREE_AND_NULL(opts->reflog_action);
+	FREE_AND_NULL(opts->default_strategy);
+	FREE_AND_NULL(opts->strategy);
 	for (size_t i = 0; i < opts->xopts_nr; i++)
 		free(opts->xopts[i]);
-	free(opts->xopts);
+	opts->xopts_nr = 0;
+	FREE_AND_NULL(opts->xopts);
 	strbuf_release(&opts->current_fixups);
 }
 
diff --git a/sequencer.h b/sequencer.h
index 888c18aad71..3bcdfa1b586 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -158,6 +158,7 @@ int sequencer_pick_revisions(struct repository *repo,
 int sequencer_continue(struct repository *repo, struct replay_opts *opts);
 int sequencer_rollback(struct repository *repo, struct replay_opts *opts);
 int sequencer_skip(struct repository *repo, struct replay_opts *opts);
+void replay_opts_release(struct replay_opts *opts);
 int sequencer_remove_state(struct replay_opts *opts);
 
 #define TODO_LIST_KEEP_EMPTY (1U << 0)
diff --git a/t/t3405-rebase-malformed.sh b/t/t3405-rebase-malformed.sh
index 25243318618..8979bc34073 100755
--- a/t/t3405-rebase-malformed.sh
+++ b/t/t3405-rebase-malformed.sh
@@ -5,6 +5,7 @@ test_description='rebase should handle arbitrary git message'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-rebase.sh
 
diff --git a/t/t3412-rebase-root.sh b/t/t3412-rebase-root.sh
index 58371d8a547..e75b3d0e07c 100755
--- a/t/t3412-rebase-root.sh
+++ b/t/t3412-rebase-root.sh
@@ -7,6 +7,7 @@ Tests if git rebase --root --onto <newparent> can rebase the root commit.
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 log_with_names () {
diff --git a/t/t3423-rebase-reword.sh b/t/t3423-rebase-reword.sh
index 4859bb8f722..2fab703d615 100755
--- a/t/t3423-rebase-reword.sh
+++ b/t/t3423-rebase-reword.sh
@@ -2,6 +2,7 @@
 
 test_description='git rebase interactive with rewording'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 . "$TEST_DIRECTORY"/lib-rebase.sh
diff --git a/t/t3437-rebase-fixup-options.sh b/t/t3437-rebase-fixup-options.sh
index c023fefd681..274699dadb8 100755
--- a/t/t3437-rebase-fixup-options.sh
+++ b/t/t3437-rebase-fixup-options.sh
@@ -14,6 +14,7 @@ to the "fixup" command that works with "fixup!", "fixup -C" works with
 "amend!" upon --autosquash.
 '
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 . "$TEST_DIRECTORY"/lib-rebase.sh
diff --git a/t/t3438-rebase-broken-files.sh b/t/t3438-rebase-broken-files.sh
index b92a3ce46b8..c614c4f2e4b 100755
--- a/t/t3438-rebase-broken-files.sh
+++ b/t/t3438-rebase-broken-files.sh
@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='rebase behavior when on-disk files are broken'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'set up conflicting branches' '
diff --git a/t/t7402-submodule-rebase.sh b/t/t7402-submodule-rebase.sh
index ebeca12a711..b19792b3269 100755
--- a/t/t7402-submodule-rebase.sh
+++ b/t/t7402-submodule-rebase.sh
@@ -5,6 +5,7 @@
 
 test_description='Test rebasing, stashing, etc. with submodules'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '
diff --git a/t/t9106-git-svn-commit-diff-clobber.sh b/t/t9106-git-svn-commit-diff-clobber.sh
index 3cab0b9720a..bca496c40e0 100755
--- a/t/t9106-git-svn-commit-diff-clobber.sh
+++ b/t/t9106-git-svn-commit-diff-clobber.sh
@@ -3,7 +3,6 @@
 # Copyright (c) 2006 Eric Wong
 test_description='git svn commit-diff clobber'
 
-TEST_FAILS_SANITIZE_LEAK=true
 . ./lib-git-svn.sh
 
 test_expect_success 'initialize repo' '
diff --git a/t/t9164-git-svn-dcommit-concurrent.sh b/t/t9164-git-svn-dcommit-concurrent.sh
index 1465156072e..c8e6c0733f4 100755
--- a/t/t9164-git-svn-dcommit-concurrent.sh
+++ b/t/t9164-git-svn-dcommit-concurrent.sh
@@ -5,7 +5,6 @@
 
 test_description='concurrent git svn dcommit'
 
-TEST_FAILS_SANITIZE_LEAK=true
 . ./lib-git-svn.sh
 
 
-- 
2.39.0.1153.g589e4efe9dc

