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// Copyright 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// #define USE_FLAGS
// #define DUMP_SUPER
// #define SAVE_FS_IMAGE
#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#include <unistd.h>
#include <assert.h>
#include <fcntl.h>
#include <sys/syscall.h>
#include <linux/memfd.h>
#include <fuzzer/FuzzedDataProvider.h>
#include "ext2fs/ext2fs.h"
extern "C" {
#include "e2p/e2p.h"
#include "support/print_fs_flags.h"
}
extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
const char *progname = "ext2fs_read_bitmap_fuzzer";
add_error_table(&et_ext2_error_table);
enum FuzzerType {
ext2fsReadBlockBitmap,
ext2fsReadInodeBitmap,
kMaxValue = ext2fsReadInodeBitmap
};
FuzzedDataProvider stream(data, size);
const FuzzerType f = stream.ConsumeEnum<FuzzerType>();
int flags = stream.ConsumeIntegral<int>();
#ifndef USE_FLAGS
flags = 0;
#endif
static const char* fname = "/tmp/ext2_test_file";
// Write our data to a temp file.
#ifdef SAVE_FS_IMAGE
int fd = open(fname, O_CREAT|O_TRUNC|O_RDWR, 0644);
#else
int fd = syscall(SYS_memfd_create, fname, 0);
#endif
std::vector<char> buffer = stream.ConsumeRemainingBytes<char>();
write(fd, buffer.data(), buffer.size());
std::string fspath("/proc/self/fd/" + std::to_string(fd));
ext2_filsys fs;
#ifdef USE_FLAGS
printf("Flags: 0x%08x ", flags);
print_fs_flags(stdout, flags);
flags &= ~EXT2_FLAG_NOFREE_ON_ERROR;
#endif
errcode_t retval = ext2fs_open(
fspath.c_str(),
flags | EXT2_FLAG_IGNORE_CSUM_ERRORS, 0, 0,
unix_io_manager,
&fs);
if (retval) {
com_err(progname, retval, "while trying to open file system");
} else {
#ifdef DUMP_SUPER
list_super2(fs->super, stdout);
#endif
switch (f) {
case ext2fsReadBlockBitmap: {
retval = ext2fs_read_block_bitmap(fs);
if (retval)
com_err(progname, retval, "while trying to read block bitmap");
break;
}
case ext2fsReadInodeBitmap: {
retval = ext2fs_read_inode_bitmap(fs);
if (retval)
com_err(progname, retval, "while trying to read inode bitmap");
break;
}
default: {
assert(false);
}
}
retval = ext2fs_close(fs);
if (retval)
com_err(progname, retval, "while trying to close file system");
}
close(fd);
return 0;
}
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