From 425908a00cdcaa4d49a513d283431b8b6eed0486 Mon Sep 17 00:00:00 2001 From: Marius Muench Date: Sun, 23 Aug 2020 10:39:34 +0200 Subject: Option for specifying forkserver initialization timeout via environment variable (#522) * Addition of AFL_FORKSRV_INIT_TMOUT env var This commit introduces a new environment variable which allows to specify the timespan AFL should wait for initial contact with the forkserver. This is useful for fuzz-targets requiring a rather long setup time before the actual fuzzing can be started (e.g., unicorn). * add .swp files to .gitignore * Inherit init_tmout in afl_fsrv_init_dup Without this patch, the forkserver would spawn with a timeout of 0 in cmplog mode, leading to an immediate crash. Additionally, this commit removes a spurious whitespace. * Initialize afl->fsrv.init_tmout in afl_fsrv_init Not all afl-components will need the new AFL_FORKSRV_INIT_TMOUT environment variable. Hence, it's initialized to the safe "default" value from before in afl_fsrv_init now. --- src/afl-fuzz.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'src/afl-fuzz.c') diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c index 664cc076..ae5cb087 100644 --- a/src/afl-fuzz.c +++ b/src/afl-fuzz.c @@ -173,6 +173,7 @@ static void usage(u8 *argv0, int more_help) { "AFL_FAST_CAL: limit the calibration stage to three cycles for speedup\n" "AFL_FORCE_UI: force showing the status screen (for virtual consoles)\n" "AFL_HANG_TMOUT: override timeout value (in milliseconds)\n" + "AFL_FORKSRV_INIT_TMOUT: time spent waiting for forkserver during startup (in milliseconds)\n" "AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES: don't warn about core dump handlers\n" "AFL_IMPORT_FIRST: sync and import test cases from other fuzzer instances first\n" "AFL_MAP_SIZE: the shared memory size for that target. must be >= the size\n" @@ -969,6 +970,22 @@ int main(int argc, char **argv_orig, char **envp) { } + if (afl->afl_env.afl_forksrv_init_tmout) { + + afl->fsrv.init_tmout = atoi(afl->afl_env.afl_forksrv_init_tmout); + if (!afl->fsrv.init_tmout) { + + FATAL("Invalid value of AFL_FORKSRV_INIT_TMOUT"); + + } + + } else { + + afl->fsrv.init_tmout = afl->fsrv.exec_tmout * FORK_WAIT_MULT; + + } + + if (afl->non_instrumented_mode == 2 && afl->no_forkserver) { FATAL("AFL_DUMB_FORKSRV and AFL_NO_FORKSRV are mutually exclusive"); -- cgit 1.4.1