// https://syzkaller.appspot.com/bug?id=31a3f2ad09a571fb7a5212efc400ce6bfc82e04c
// autogenerated by syzkaller (https://github.com/google/syzkaller)
#define _GNU_SOURCE
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include <linux/loop.h>
#ifndef __NR_memfd_create
#define __NR_memfd_create 319
#endif
static unsigned long long procid;
struct fs_image_segment {
void* data;
uintptr_t size;
uintptr_t offset;
};
#define IMAGE_MAX_SEGMENTS 4096
#define IMAGE_MAX_SIZE (129 << 20)
static unsigned long fs_image_segment_check(unsigned long size,
unsigned long nsegs,
struct fs_image_segment* segs)
{
if (nsegs > IMAGE_MAX_SEGMENTS)
nsegs = IMAGE_MAX_SEGMENTS;
for (size_t i = 0; i < nsegs; i++) {
if (segs[i].size > IMAGE_MAX_SIZE)
segs[i].size = IMAGE_MAX_SIZE;
segs[i].offset %= IMAGE_MAX_SIZE;
if (segs[i].offset > IMAGE_MAX_SIZE - segs[i].size)
segs[i].offset = IMAGE_MAX_SIZE - segs[i].size;
if (size < segs[i].offset + segs[i].offset)
size = segs[i].offset + segs[i].offset;
}
if (size > IMAGE_MAX_SIZE)
size = IMAGE_MAX_SIZE;
return size;
}
static int setup_loop_device(long unsigned size, long unsigned nsegs,
struct fs_image_segment* segs,
const char* loopname, int* memfd_p, int* loopfd_p)
{
int err = 0, loopfd = -1;
size = fs_image_segment_check(size, nsegs, segs);
int memfd = syscall(__NR_memfd_create, "syzkaller", 0);
if (memfd == -1) {
err = errno;
goto error;
}
if (ftruncate(memfd, size)) {
err = errno;
goto error_close_memfd;
}
for (size_t i = 0; i < nsegs; i++) {
if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) {
}
}
loopfd = open(loopname, O_RDWR);
if (loopfd == -1) {
err = errno;
goto error_close_memfd;
}
if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
if (errno != EBUSY) {
err = errno;
goto error_close_loop;
}
ioctl(loopfd, LOOP_CLR_FD, 0);
usleep(1000);
if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
err = errno;
goto error_close_loop;
}
}
*memfd_p = memfd;
*loopfd_p = loopfd;
return 0;
error_close_loop:
close(loopfd);
error_close_memfd:
close(memfd);
error:
errno = err;
return -1;
}
static long syz_mount_image(volatile long fsarg, volatile long dir,
volatile unsigned long size,
volatile unsigned long nsegs,
volatile long segments, volatile long flags,
volatile long optsarg)
{
struct fs_image_segment* segs = (struct fs_image_segment*)segments;
int res = -1, err = 0, loopfd = -1, memfd = -1, need_loop_device = !!segs;
char* mount_opts = (char*)optsarg;
char* target = (char*)dir;
char* fs = (char*)fsarg;
char* source = NULL;
char loopname[64];
if (need_loop_device) {
memset(loopname, 0, sizeof(loopname));
snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
if (setup_loop_device(size, nsegs, segs, loopname, &memfd, &loopfd) == -1)
return -1;
source = loopname;
}
mkdir(target, 0777);
char opts[256];
memset(opts, 0, sizeof(opts));
if (strlen(mount_opts) > (sizeof(opts) - 32)) {
}
strncpy(opts, mount_opts, sizeof(opts) - 32);
if (strcmp(fs, "iso9660") == 0) {
flags |= MS_RDONLY;
} else if (strncmp(fs, "ext", 3) == 0) {
if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0)
strcat(opts, ",errors=continue");
} else if (strcmp(fs, "xfs") == 0) {
strcat(opts, ",nouuid");
}
res = mount(source, target, fs, flags, opts);
if (res == -1) {
err = errno;
goto error_clear_loop;
}
res = open(target, O_RDONLY | O_DIRECTORY);
if (res == -1) {
err = errno;
}
error_clear_loop:
if (need_loop_device) {
ioctl(loopfd, LOOP_CLR_FD, 0);
close(loopfd);
close(memfd);
}
errno = err;
return res;
}
uint64_t r[1] = {0xffffffffffffffff};
int main(void)
{
syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul);
syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
intptr_t res = 0;
memcpy((void*)0x20000000, "ext4\000", 5);
memcpy((void*)0x20000040, "./file0\000", 8);
*(uint64_t*)0x20000540 = 0x20010000;
memcpy((void*)0x20010000,
"\x20\x00\x00\x00\x00\x02\x00\x00\x19\x00\x00\x00\x60\x01\x00\x00\x0f"
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00"
"\x02\x00\x00\x20\x00\x00\x20\x00\x00\x00\xdd\xf4\x65\x5f\xdd\xf4\x65"
"\x5f\x01\x00\xff\xff\x53\xef\x2e\x47\x01\x00\x00\x00\xdd\xf4\x65\x5f"
"\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x0b"
"\x00\x00\x00\x00\x01\x00\x00\x08\x00\x00\x00\xd2\x42\x00\x00\x12\x03",
102);
*(uint64_t*)0x20000548 = 0x66;
*(uint64_t*)0x20000550 = 0x400;
*(uint64_t*)0x20000558 = 0x20010100;
memcpy((void*)0x20010100,
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x68\x56\xd4\x9a\x00"
"\xcc\x43\x71\xbd\x6a\x7c\x89\x3f\x28\x00\x45\x01\x00\x40",
31);
*(uint64_t*)0x20000560 = 0x1f;
*(uint64_t*)0x20000568 = 0x4e0;
*(uint64_t*)0x20000570 = 0x20010400;
memcpy((void*)0x20010400, "\x03\x00\x00\x00\x04\x00\x00\x00\x05", 9);
*(uint64_t*)0x20000578 = 9;
*(uint64_t*)0x20000580 = 0x800;
*(uint64_t*)0x20000588 = 0x20000080;
memcpy((void*)0x20000080,
"\xed\x41\x00\x00\x00\x04\x00\x00\xdd\xf4\x65\x5f\xdd\xf4\x04\x00\xdd"
"\xf4\x65\x5f\x00\x00\x00\x00\x00\x00\xe4\xcb\x7a\x7a\xa7\xb5\x28\x46"
"\xdd\x12\x93\xbd\x8f\x41\xe4\x9f\x2a",
43);
*(uint64_t*)0x20000590 = 0x2b;
*(uint64_t*)0x20000598 = 0x1500;
*(uint8_t*)0x20000140 = 0;
res = -1;
res = syz_mount_image(0x20000000, 0x20000040, 0x83600, 4, 0x20000540, 0x81,
0x20000140);
if (res != -1)
r[0] = res;
memcpy((void*)0x20000100, "./file0/file0\000", 14);
syscall(__NR_openat, r[0], 0x20000100ul, 0xc880ul, 0ul);
return 0;
}