qemu/tests/qtest/fuzz/fuzz.h
Alexander Bulekov f5ec79f5e0 fuzz: Expect the cmdline in a freeable GString
In the initial FuzzTarget, get_init_cmdline returned a char *. With this
API, we had no guarantee about where the string came from. For example,
i440fx-qtest-reboot-fuzz simply returned a pointer to a string literal,
while the QOS-based targets build the arguments out in a GString an
return the gchar *str pointer. Since we did not try to free the cmdline,
we have a leak for any targets that do not simply return string
literals. Clean up this mess by forcing fuzz-targets to return
a GString, that we can free.

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20200714174616.20709-1-alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-07-17 10:44:23 +02:00

99 lines
2.5 KiB
C

/*
* fuzzing driver
*
* Copyright Red Hat Inc., 2019
*
* Authors:
* Alexander Bulekov <alxndr@bu.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef FUZZER_H_
#define FUZZER_H_
#include "qemu/osdep.h"
#include "qemu/units.h"
#include "qapi/error.h"
#include "tests/qtest/libqtest.h"
/**
* A libfuzzer fuzzing target
*
* The QEMU fuzzing binary is built with all available targets, each
* with a unique @name that can be specified on the command-line to
* select which target should run.
*
* A target must implement ->fuzz() to process a random input. If QEMU
* crashes in ->fuzz() then libfuzzer will record a failure.
*
* Fuzzing targets are registered with fuzz_add_target():
*
* static const FuzzTarget fuzz_target = {
* .name = "my-device-fifo",
* .description = "Fuzz the FIFO buffer registers of my-device",
* ...
* };
*
* static void register_fuzz_target(void)
* {
* fuzz_add_target(&fuzz_target);
* }
* fuzz_target_init(register_fuzz_target);
*/
typedef struct FuzzTarget {
const char *name; /* target identifier (passed to --fuzz-target=)*/
const char *description; /* help text */
/*
* Returns the arguments that are passed to qemu/softmmu init(). Freed by
* the caller.
*/
GString *(*get_init_cmdline)(struct FuzzTarget *);
/*
* will run once, prior to running qemu/softmmu init.
* eg: set up shared-memory for communication with the child-process
* Can be NULL
*/
void(*pre_vm_init)(void);
/*
* will run once, after QEMU has been initialized, prior to the fuzz-loop.
* eg: detect the memory map
* Can be NULL
*/
void(*pre_fuzz)(QTestState *);
/*
* accepts and executes an input from libfuzzer. this is repeatedly
* executed during the fuzzing loop. Its should handle setup, input
* execution and cleanup.
* Cannot be NULL
*/
void(*fuzz)(QTestState *, const unsigned char *, size_t);
} FuzzTarget;
void flush_events(QTestState *);
void reboot(QTestState *);
/* Use the QTest ASCII protocol or call address_space API directly?*/
void fuzz_qtest_set_serialize(bool option);
/*
* makes a copy of *target and adds it to the target-list.
* i.e. fine to set up target on the caller's stack
*/
void fuzz_add_target(const FuzzTarget *target);
int LLVMFuzzerTestOneInput(const unsigned char *Data, size_t Size);
int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp);
#endif