Fuzzer is supposed to stop when first bug is found and report failure.
Present fuzzers fork new child at each iteration to isolate side-effects.
But child's exit code is ignored, i.e. libfuzzer does not see any crashes.
Right now virtio-net fuzzer instantly falls on assert in iov_copy and
dumps crash-*, but fuzzing continues and ends successfully if global
timeout is set.
Let's put required logic into helper function "fork_fuzzer_and_wait".
Signed-off-by: Konstantin Khlebnikov <khlebni...@yandex-team.ru>
---
tests/qtest/fuzz/fork_fuzz.c | 26 ++++++++++++++++++++++++++
tests/qtest/fuzz/fork_fuzz.h | 1 +
tests/qtest/fuzz/generic_fuzz.c | 3 +--
tests/qtest/fuzz/i440fx_fuzz.c | 3 +--
tests/qtest/fuzz/virtio_blk_fuzz.c | 6 ++----
tests/qtest/fuzz/virtio_net_fuzz.c | 6 ++----
tests/qtest/fuzz/virtio_scsi_fuzz.c | 6 ++----
7 files changed, 35 insertions(+), 16 deletions(-)
diff --git a/tests/qtest/fuzz/fork_fuzz.c b/tests/qtest/fuzz/fork_fuzz.c
index 6ffb2a7937..6e3a3867bf 100644
--- a/tests/qtest/fuzz/fork_fuzz.c
+++ b/tests/qtest/fuzz/fork_fuzz.c
@@ -38,4 +38,30 @@ void counter_shm_init(void)
free(copy);
}
+/* Returns true in child process */
+bool fork_fuzzer_and_wait(void)
+{
+ pid_t pid;
+ int wstatus;
+
+ pid = fork();
+ if (pid < 0) {
+ perror("fork");
+ abort();
+ }
+
+ if (pid == 0) {
+ return true;
+ }
+ if (waitpid(pid, &wstatus, 0) < 0) {
+ perror("waitpid");
+ abort();
+ }
+
+ if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus) != 0) {
+ abort();
+ }
+
+ return false;
+}
diff --git a/tests/qtest/fuzz/fork_fuzz.h b/tests/qtest/fuzz/fork_fuzz.h
index 9ecb8b58ef..792e922731 100644
--- a/tests/qtest/fuzz/fork_fuzz.h
+++ b/tests/qtest/fuzz/fork_fuzz.h
@@ -18,6 +18,7 @@ extern uint8_t __FUZZ_COUNTERS_START;
extern uint8_t __FUZZ_COUNTERS_END;
void counter_shm_init(void);
+bool fork_fuzzer_and_wait(void);
#endif
diff --git a/tests/qtest/fuzz/generic_fuzz.c b/tests/qtest/fuzz/generic_fuzz.c
index dd7e25851c..f0e25b39ea 100644
--- a/tests/qtest/fuzz/generic_fuzz.c
+++ b/tests/qtest/fuzz/generic_fuzz.c
@@ -667,7 +667,7 @@ static void generic_fuzz(QTestState *s, const unsigned char
*Data, size_t Size)
size_t cmd_len;
uint8_t op;
- if (fork() == 0) {
+ if (fork_fuzzer_and_wait()) {
struct sigaction sact;
struct itimerval timer;
sigset_t set;
@@ -723,7 +723,6 @@ static void generic_fuzz(QTestState *s, const unsigned char
*Data, size_t Size)
_Exit(0);
} else {
flush_events(s);
- wait(0);
}
}
diff --git a/tests/qtest/fuzz/i440fx_fuzz.c b/tests/qtest/fuzz/i440fx_fuzz.c
index 86796bff2b..0b927f4b3a 100644
--- a/tests/qtest/fuzz/i440fx_fuzz.c
+++ b/tests/qtest/fuzz/i440fx_fuzz.c
@@ -147,12 +147,11 @@ static void i440fx_fuzz_qos(QTestState *s,
static void i440fx_fuzz_qos_fork(QTestState *s,
const unsigned char *Data, size_t Size) {
- if (fork() == 0) {
+ if (fork_fuzzer_and_wait()) {
i440fx_fuzz_qos(s, Data, Size);
_Exit(0);
} else {
flush_events(s);
- wait(NULL);
}
}
diff --git a/tests/qtest/fuzz/virtio_blk_fuzz.c
b/tests/qtest/fuzz/virtio_blk_fuzz.c
index 623a756fd4..9532dc1fa7 100644
--- a/tests/qtest/fuzz/virtio_blk_fuzz.c
+++ b/tests/qtest/fuzz/virtio_blk_fuzz.c
@@ -136,13 +136,12 @@ static void virtio_blk_fork_fuzz(QTestState *s,
if (!queues) {
queues = qvirtio_blk_init(blk->vdev, 0);
}
- if (fork() == 0) {
+ if (fork_fuzzer_and_wait()) {
virtio_blk_fuzz(s, queues, Data, Size);
flush_events(s);
_Exit(0);
} else {
flush_events(s);
- wait(NULL);
}
}
@@ -152,7 +151,7 @@ static void virtio_blk_with_flag_fuzz(QTestState *s,
QVirtioBlk *blk = fuzz_qos_obj;
static QVirtioBlkQueues *queues;
- if (fork() == 0) {
+ if (fork_fuzzer_and_wait()) {
if (Size >= sizeof(uint64_t)) {
queues = qvirtio_blk_init(blk->vdev, *(uint64_t *)Data);
virtio_blk_fuzz(s, queues,
@@ -162,7 +161,6 @@ static void virtio_blk_with_flag_fuzz(QTestState *s,
_Exit(0);
} else {
flush_events(s);
- wait(NULL);
}
}
diff --git a/tests/qtest/fuzz/virtio_net_fuzz.c
b/tests/qtest/fuzz/virtio_net_fuzz.c
index 0e873ab8e2..6b492ef9e7 100644
--- a/tests/qtest/fuzz/virtio_net_fuzz.c
+++ b/tests/qtest/fuzz/virtio_net_fuzz.c
@@ -118,26 +118,24 @@ static void virtio_net_fuzz_multi(QTestState *s,
static void virtio_net_fork_fuzz(QTestState *s,
const unsigned char *Data, size_t Size)
{
- if (fork() == 0) {
+ if (fork_fuzzer_and_wait()) {
virtio_net_fuzz_multi(s, Data, Size, false);
flush_events(s);
_Exit(0);
} else {
flush_events(s);
- wait(NULL);
}
}
static void virtio_net_fork_fuzz_check_used(QTestState *s,
const unsigned char *Data, size_t Size)
{
- if (fork() == 0) {
+ if (fork_fuzzer_and_wait()) {
virtio_net_fuzz_multi(s, Data, Size, true);
flush_events(s);
_Exit(0);
} else {
flush_events(s);
- wait(NULL);
}
}
diff --git a/tests/qtest/fuzz/virtio_scsi_fuzz.c
b/tests/qtest/fuzz/virtio_scsi_fuzz.c
index 6ff6fabe4a..c7eaf3242b 100644
--- a/tests/qtest/fuzz/virtio_scsi_fuzz.c
+++ b/tests/qtest/fuzz/virtio_scsi_fuzz.c
@@ -140,13 +140,12 @@ static void virtio_scsi_fork_fuzz(QTestState *s,
if (!queues) {
queues = qvirtio_scsi_init(scsi->vdev, 0);
}
- if (fork() == 0) {
+ if (fork_fuzzer_and_wait()) {
virtio_scsi_fuzz(s, queues, Data, Size);
flush_events(s);
_Exit(0);
} else {
flush_events(s);
- wait(NULL);
}
}
@@ -156,7 +155,7 @@ static void virtio_scsi_with_flag_fuzz(QTestState *s,
QVirtioSCSI *scsi = fuzz_qos_obj;
static QVirtioSCSIQueues *queues;
- if (fork() == 0) {
+ if (fork_fuzzer_and_wait()) {
if (Size >= sizeof(uint64_t)) {
queues = qvirtio_scsi_init(scsi->vdev, *(uint64_t *)Data);
virtio_scsi_fuzz(s, queues,
@@ -166,7 +165,6 @@ static void virtio_scsi_with_flag_fuzz(QTestState *s,
_Exit(0);
} else {
flush_events(s);
- wait(NULL);
}
}
