# [PATCH] test-mktemp: plug memory and descriptor leaks 1 messages from 2025-11-18 to 2025-11-18. Participants: Jeff King. Thread: https://gitlist.dev/t/64505 ## Jeff King, 2025-11-18 12:21 Subject: [PATCH] test-mktemp: plug memory and descriptor leaks Message-ID: <20251118122124.GA1117960@coredump.intra.peff.net> URL: https://gitlist.dev/e/20251118122124.GA1117960%40coredump.intra.peff.net ``` We test xmkstemp() in our helper by just calling: xmkstemp(xstrdup(argv[1])); This leaks both the copied string as well as the descriptor returned by the function. In practice this isn't a big deal, since we immediately exit the program, but: 1. LSan will complain about the memory leak. The only reason we did not notice this in our leak-checking builds is that both of the callers in the test suite (both in t0070) pass a broken template (and expect failure). So the function calls die() before we can actually leak. But it's an accident waiting to happen if anybody adds a call which succeeds. 2. Coverity complains about the descriptor leak. There's a long list of uninteresting or false positives in Coverity's results, but since we're here we might as well fix it, too. I didn't bother adding a new test that triggers the leak. It's not even in real production code, but just in the test-helper itself. Signed-off-by: Jeff King --- I think the rewrite of xmkstemp() triggered Coverity to consider this a "new" problem, even though it has been there for years. So not urgent, but this is mostly just trying not to waste the brain cycles I spent analyzing. :) t/helper/test-mktemp.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/t/helper/test-mktemp.c b/t/helper/test-mktemp.c index 2290688940..da195640a9 100644 --- a/t/helper/test-mktemp.c +++ b/t/helper/test-mktemp.c @@ -6,10 +6,16 @@ int cmd__mktemp(int argc, const char **argv) { + char *template; + int fd; + if (argc != 2) usage("Expected 1 parameter defining the temporary file template"); + template = xstrdup(argv[1]); - xmkstemp(xstrdup(argv[1])); + fd = xmkstemp(template); + close(fd); + free(template); return 0; } -- 2.52.0.292.gf04cec7acc ```