From f84ea696606b3dd6ae40006e5efb9f178651e916 Mon Sep 17 00:00:00 2001 From: Nils Bars Date: Thu, 20 Oct 2022 13:14:29 +0200 Subject: Fix child reaping on fuzzer termination This commit contains the following changes: - Call `waitpid()` on the child and the fork server when terminating the fuzzer; thus, we do not end up with zombies. - Rename `fsrv.kill_signal` to `fsrv.child_kill_signal`, since the documentation states that the signal is used to terminate the *child*. - Use SIGTERM instead of fsrv.(child)_kill_signal, thus the fork server can always reap the child. --- src/afl-fuzz-state.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'src/afl-fuzz-state.c') diff --git a/src/afl-fuzz-state.c b/src/afl-fuzz-state.c index 5199f7e6..8bbef87c 100644 --- a/src/afl-fuzz-state.c +++ b/src/afl-fuzz-state.c @@ -23,6 +23,7 @@ */ +#include #include "afl-fuzz.h" #include "envs.h" @@ -653,9 +654,14 @@ void afl_states_stop(void) { }); LIST_FOREACH(&afl_states, afl_state_t, { - - if (el->fsrv.child_pid > 0) kill(el->fsrv.child_pid, el->fsrv.kill_signal); - if (el->fsrv.fsrv_pid > 0) kill(el->fsrv.fsrv_pid, el->fsrv.kill_signal); + /* NOTE: We need to make sure that the parent (the forkserver) reap the child (see below). */ + if (el->fsrv.child_pid > 0) kill(el->fsrv.child_pid, el->fsrv.child_kill_signal); + if (el->fsrv.fsrv_pid > 0) { + /* This must be SIGTERM, to allow the forkserver to reap the child before exiting. */ + kill(el->fsrv.fsrv_pid, SIGTERM); + /* Make sure the forkserver does not end up as zombie. */ + waitpid(el->fsrv.fsrv_pid, NULL, 0); + } }); @@ -672,4 +678,3 @@ void afl_states_request_skip(void) { LIST_FOREACH(&afl_states, afl_state_t, { el->skip_requested = 1; }); } - -- cgit 1.4.1