From: Junio C Hamano Date: Wed, 25 Feb 2026 21:01:20 GMT Subject: Re: [PATCH v6 01/10] fsmonitor: fix khash memory leak in do_handle_client Message-ID: In-Reply-To: <4d4dec8fa161926e6f6ac822aff0db35353705eb.1772050636.git.gitgitgadget@gmail.com> "Paul Tarjan via GitGitGadget" writes: > From: Paul Tarjan > > The `shown` kh_str_t was freed with kh_release_str() at a point in > the code only reachable in the non-trivial response path. When the > client receives a trivial response, the code jumps to the `cleanup` > label, skipping the kh_release_str() call entirely and leaking the > hash table. > > Fix this by initializing `shown` to NULL and moving the cleanup to the > `cleanup` label using kh_destroy_str(), which is safe to call on NULL. > This ensures the hash table is freed regardless of which code path is > taken. Makes perfect sense, the changes to the code matches the description, and the difference between kh_release_* and kh_destroy_* in khash.h is exactly as described in the log message. Perfect. I wish all the patches posted here are as easy to review as this one ;-) > Signed-off-by: Paul Tarjan > --- > builtin/fsmonitor--daemon.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/builtin/fsmonitor--daemon.c b/builtin/fsmonitor--daemon.c > index 242c594646..bc4571938c 100644 > --- a/builtin/fsmonitor--daemon.c > +++ b/builtin/fsmonitor--daemon.c > @@ -671,7 +671,7 @@ static int do_handle_client(struct fsmonitor_daemon_state *state, > const struct fsmonitor_batch *batch; > struct fsmonitor_batch *remainder = NULL; > intmax_t count = 0, duplicates = 0; > - kh_str_t *shown; > + kh_str_t *shown = NULL; > int hash_ret; > int do_trivial = 0; > int do_flush = 0; > @@ -909,8 +909,6 @@ static int do_handle_client(struct fsmonitor_daemon_state *state, > total_response_len += payload.len; > } > > - kh_release_str(shown); > - > pthread_mutex_lock(&state->main_lock); > > if (token_data->client_ref_count > 0) > @@ -954,6 +952,7 @@ static int do_handle_client(struct fsmonitor_daemon_state *state, > trace2_data_intmax("fsmonitor", the_repository, "response/count/duplicates", duplicates); > > cleanup: > + kh_destroy_str(shown); > strbuf_release(&response_token); > strbuf_release(&requested_token_id); > strbuf_release(&payload);