// https://syzkaller.appspot.com/bug?id=3f86c0edf75c86d2633aeb9dd69eccc70bc7e90b // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #include #include #include #include const int kFailStatus = 67; const int kRetryStatus = 69; static void fail(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus); } static void exitf(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit(kRetryStatus); } #define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1) #define BITMASK_LEN_OFF(type, bf_off, bf_len) \ (type)(BITMASK_LEN(type, (bf_len)) << (bf_off)) #define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len) \ if ((bf_off) == 0 && (bf_len) == 0) { \ *(type*)(addr) = (type)(val); \ } else { \ type new_val = *(type*)(addr); \ new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len)); \ new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off); \ *(type*)(addr) = new_val; \ } static void use_temporary_dir() { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); } static uintptr_t syz_fuse_mount(uintptr_t a0, uintptr_t a1, uintptr_t a2, uintptr_t a3, uintptr_t a4, uintptr_t a5) { uint64_t target = a0; uint64_t mode = a1; uint64_t uid = a2; uint64_t gid = a3; uint64_t maxread = a4; uint64_t flags = a5; int fd = open("/dev/fuse", O_RDWR); if (fd == -1) return fd; char buf[1024]; sprintf(buf, "fd=%d,user_id=%ld,group_id=%ld,rootmode=0%o", fd, (long)uid, (long)gid, (unsigned)mode & ~3u); if (maxread != 0) sprintf(buf + strlen(buf), ",max_read=%ld", (long)maxread); if (mode & 1) strcat(buf, ",default_permissions"); if (mode & 2) strcat(buf, ",allow_other"); syscall(SYS_mount, "", target, "fuse", flags, buf); return fd; } extern 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) #define SYZ_memfd_create 319 static uintptr_t syz_mount_image(uintptr_t fs, uintptr_t dir, uintptr_t size, uintptr_t nsegs, uintptr_t segments, uintptr_t flags, uintptr_t opts) { char loopname[64]; int loopfd, err = 0, res = -1; uintptr_t i; struct fs_image_segment* segs = (struct fs_image_segment*)segments; if (nsegs > IMAGE_MAX_SEGMENTS) nsegs = IMAGE_MAX_SEGMENTS; for (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; int memfd = syscall(SYZ_memfd_create, "syz_mount_image", 0); if (memfd == -1) { err = errno; goto error; } if (ftruncate(memfd, size)) { err = errno; goto error_close_memfd; } for (i = 0; i < nsegs; i++) { if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) { } } snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid); 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; } } mkdir((char*)dir, 0777); if (strcmp((char*)fs, "iso9660") == 0) flags |= MS_RDONLY; if (mount(loopname, (char*)dir, (char*)fs, flags, (char*)opts)) { err = errno; goto error_clear_loop; } res = 0; error_clear_loop: ioctl(loopfd, LOOP_CLR_FD, 0); error_close_loop: close(loopfd); error_close_memfd: close(memfd); error: errno = err; return res; } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static void setup_cgroups() { if (mkdir("/syzcgroup", 0777)) { } if (mkdir("/syzcgroup/unified", 0777)) { } if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) { } if (chmod("/syzcgroup/unified", 0777)) { } if (!write_file("/syzcgroup/unified/cgroup.subtree_control", "+cpu +memory +io +pids +rdma")) { } if (mkdir("/syzcgroup/cpu", 0777)) { } if (mount("none", "/syzcgroup/cpu", "cgroup", 0, "cpuset,cpuacct,perf_event,hugetlb")) { } if (!write_file("/syzcgroup/cpu/cgroup.clone_children", "1")) { } if (chmod("/syzcgroup/cpu", 0777)) { } if (mkdir("/syzcgroup/net", 0777)) { } if (mount("none", "/syzcgroup/net", "cgroup", 0, "net_cls,net_prio,devices,freezer")) { } if (chmod("/syzcgroup/net", 0777)) { } } static void setup_binfmt_misc() { if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz0:M:0:syz0::./file0:")) { } if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz1:M:1:yz1::./file0:POC")) { } } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 160 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; setup_cgroups(); setup_binfmt_misc(); sandbox_common(); if (unshare(CLONE_NEWNET)) { } loop(); doexit(1); } static int inject_fault(int nth) { int fd; char buf[16]; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exitf("failed to open /proc/thread-self/fail-nth"); sprintf(buf, "%d", nth + 1); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exitf("failed to write /proc/thread-self/fail-nth"); return fd; } static void execute_one(); extern unsigned long long procid; void loop() { while (1) { execute_one(); } } unsigned long long procid; void execute_one() { *(uint32_t*)0x20000140 = 2; *(uint32_t*)0x20000144 = 0x70; *(uint8_t*)0x20000148 = 0xe3; *(uint8_t*)0x20000149 = 0; *(uint8_t*)0x2000014a = 0; *(uint8_t*)0x2000014b = 0; *(uint32_t*)0x2000014c = 0; *(uint64_t*)0x20000150 = 0; *(uint64_t*)0x20000158 = 0; *(uint64_t*)0x20000160 = 0; STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 0, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 1, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 2, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 3, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 4, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 5, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 6, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 7, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 8, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 9, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 10, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 11, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 12, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 13, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 14, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 15, 2); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 17, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 18, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 19, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 20, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 21, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 22, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 23, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 24, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 25, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 26, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 27, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 28, 1); STORE_BY_BITMASK(uint64_t, 0x20000168, 0, 29, 35); *(uint32_t*)0x20000170 = 0; *(uint32_t*)0x20000174 = 0; *(uint64_t*)0x20000178 = 0x20000080; *(uint64_t*)0x20000180 = 0; *(uint64_t*)0x20000188 = 0; *(uint64_t*)0x20000190 = 0; *(uint32_t*)0x20000198 = 0; *(uint32_t*)0x2000019c = 0; *(uint64_t*)0x200001a0 = 0; *(uint32_t*)0x200001a8 = 0; *(uint16_t*)0x200001ac = 0; *(uint16_t*)0x200001ae = 0; syscall(__NR_perf_event_open, 0x20000140, 0, -1, -1, 0); memcpy((void*)0x20000000, "vfat", 5); memcpy((void*)0x200004c0, "./file0", 8); syz_mount_image(0x20000000, 0x200004c0, 0, 0, 0x20000040, 0, 0x20000240); memcpy((void*)0x20000400, "./file0", 8); write_file("/sys/kernel/debug/failslab/ignore-gfp-wait", "N"); write_file("/sys/kernel/debug/fail_futex/ignore-private", "N"); inject_fault(78); syz_fuse_mount(0x20000400, 0x1000, 0, 0, 0, 0); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); char* cwd = get_current_dir_name(); for (procid = 0; procid < 8; procid++) { if (fork() == 0) { for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } } } sleep(1000000); return 0; }