[PATCH] rebase: use child_process_clear() to clean
- From
Jeff King <peff@peff.net>
- Date
- Mar 22, 2024, 10:35 UTC
- Message-ID
- <20240322103502.GA2045297@coredump.intra.peff.net>
In the run_am() function, we set up a child_process struct to run "git-am", allocating memory for its args and env strvecs. These are normally cleaned up when we call run_command(). But if we encounter certain errors, we exit the function early and try to clean up ourselves by clearing the am.args field. This leaks the "env" strvec.
We should use child_process_clear() instead, which covers both. And more importantly, it future proofs us against the struct ever growing more allocated fields.
These are unlikely errors to happen in practice, so they don't actually trigger the leak sanitizer in the tests. But we can add a new test which does exercise one of the paths (and fails SANITIZE=leak without this patch).
Signed-off-by: Jeff King <peff@peff.net> --- I noticed this when investigating a different leak, since that other one caused format-patch to crash, hitting one of the error paths. ;)
The results of "git grep 'strvec_clear.*\.args'" imply the problem doesn't exist elsewhere (arguably the hit in test-trace2.c should use child_process_clear() to set a good example, but it's already a bit of an oddball use of the struct).
Not sure if the test is overkill. It really does nothing useful in a non-leak-checking build.
builtin/rebase.c | 6 +++--- t/t3438-rebase-broken-files.sh | 9 +++++++++ 2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/builtin/rebase.c b/builtin/rebase.c index e444ab102d..b9d0fb3269 100644 --- a/builtin/rebase.c +++ b/builtin/rebase.c @@ -610,7 +610,7 @@ static int run_am(struct rebase_options *opts) status = error_errno(_("could not open '%s' for writing"), rebased_patches); free(rebased_patches); - strvec_clear(&am.args); + child_process_clear(&am); return status; } @@ -638,7 +638,7 @@ static int run_am(struct rebase_options *opts) struct reset_head_opts ropts = { 0 }; unlink(rebased_patches); free(rebased_patches); - strvec_clear(&am.args); + child_process_clear(&am); ropts.oid = &opts->orig_head->object.oid; ropts.branch = opts->head_name; @@ -659,7 +659,7 @@ static int run_am(struct rebase_options *opts) status = error_errno(_("could not open '%s' for reading"), rebased_patches); free(rebased_patches); - strvec_clear(&am.args); + child_process_clear(&am); return status; } diff --git a/t/t3438-rebase-broken-files.sh b/t/t3438-rebase-broken-files.sh index c614c4f2e4..821f08e5af 100755 --- a/t/t3438-rebase-broken-files.sh +++ b/t/t3438-rebase-broken-files.sh @@ -58,4 +58,13 @@ test_expect_success 'unknown key in author-script' ' check_resolve_fails ' +test_expect_success POSIXPERM,SANITY 'unwritable rebased-patches does not leak' ' + >.git/rebased-patches && + chmod a-w .git/rebased-patches && + + git checkout -b side HEAD^ && + test_commit unrelated && + test_must_fail git rebase --apply --onto tmp HEAD^ +' + test_done
-- 2.44.0.682.g01e1dab148