Syzkaller reproducer: # {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}} syz_mount_image$ext4(&(0x7f0000000600)='ext4\x00', &(0x7f0000000640)='./file1\x00', 0x0, &(0x7f0000000080)={[{@norecovery}, {@debug_want_extra_isize={'debug_want_extra_isize', 0x3d, 0x3e}}]}, 0x1, 0x603, &(0x7f0000000d80)="$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") lchown(&(0x7f0000001600)='./file1\x00', 0x0, 0x0) lsetxattr$trusted_overlay_upper(&(0x7f0000000700)='./file1\x00', &(0x7f0000000740), &(0x7f0000000f40)=ANY=[], 0xe1, 0x0) C reproducer: // autogenerated by syzkaller (https://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 #ifndef __NR_memfd_create #define __NR_memfd_create 319 #endif static unsigned long long procid; static __thread int clone_ongoing; static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) { exit(sig); } uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0; int valid = addr < prog_start || addr > prog_end; if (skip && valid) { _longjmp(segv_env, 1); } exit(sig); } static void install_segv_handler(void) { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ ({ \ int ok = 1; \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } else \ ok = 0; \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ ok; \ }) static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } static void thread_start(void* (*fn)(void*), void* arg) { pthread_t th; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); int i = 0; for (; i < 100; i++) { if (pthread_create(&th, &attr, fn, arg) == 0) { pthread_attr_destroy(&attr); return; } if (errno == EAGAIN) { usleep(50); continue; } break; } exit(1); } typedef struct { int state; } event_t; static void event_init(event_t* ev) { ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { if (ev->state) exit(1); __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000); } static void event_wait(event_t* ev) { while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0); } static int event_isset(event_t* ev) { return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE); } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; for (;;) { uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts); if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) return 1; now = current_time_ms(); if (now - start > timeout) return 0; } } 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; } //% This code is derived from puff.{c,h}, found in the zlib development. The //% original files come with the following copyright notice: //% Copyright (C) 2002-2013 Mark Adler, all rights reserved //% version 2.3, 21 Jan 2013 //% This software is provided 'as-is', without any express or implied //% warranty. In no event will the author be held liable for any damages //% arising from the use of this software. //% Permission is granted to anyone to use this software for any purpose, //% including commercial applications, and to alter it and redistribute it //% freely, subject to the following restrictions: //% 1. The origin of this software must not be misrepresented; you must not //% claim that you wrote the original software. If you use this software //% in a product, an acknowledgment in the product documentation would be //% appreciated but is not required. //% 2. Altered source versions must be plainly marked as such, and must not be //% misrepresented as being the original software. //% 3. This notice may not be removed or altered from any source distribution. //% Mark Adler madler@alumni.caltech.edu //% BEGIN CODE DERIVED FROM puff.{c,h} #define MAXBITS 15 #define MAXLCODES 286 #define MAXDCODES 30 #define MAXCODES (MAXLCODES + MAXDCODES) #define FIXLCODES 288 struct puff_state { unsigned char* out; unsigned long outlen; unsigned long outcnt; const unsigned char* in; unsigned long inlen; unsigned long incnt; int bitbuf; int bitcnt; jmp_buf env; }; static int puff_bits(struct puff_state* s, int need) { long val = s->bitbuf; while (s->bitcnt < need) { if (s->incnt == s->inlen) longjmp(s->env, 1); val |= (long)(s->in[s->incnt++]) << s->bitcnt; s->bitcnt += 8; } s->bitbuf = (int)(val >> need); s->bitcnt -= need; return (int)(val & ((1L << need) - 1)); } static int puff_stored(struct puff_state* s) { s->bitbuf = 0; s->bitcnt = 0; if (s->incnt + 4 > s->inlen) return 2; unsigned len = s->in[s->incnt++]; len |= s->in[s->incnt++] << 8; if (s->in[s->incnt++] != (~len & 0xff) || s->in[s->incnt++] != ((~len >> 8) & 0xff)) return -2; if (s->incnt + len > s->inlen) return 2; if (s->outcnt + len > s->outlen) return 1; for (; len--; s->outcnt++, s->incnt++) { if (s->in[s->incnt]) s->out[s->outcnt] = s->in[s->incnt]; } return 0; } struct puff_huffman { short* count; short* symbol; }; static int puff_decode(struct puff_state* s, const struct puff_huffman* h) { int first = 0; int index = 0; int bitbuf = s->bitbuf; int left = s->bitcnt; int code = first = index = 0; int len = 1; short* next = h->count + 1; while (1) { while (left--) { code |= bitbuf & 1; bitbuf >>= 1; int count = *next++; if (code - count < first) { s->bitbuf = bitbuf; s->bitcnt = (s->bitcnt - len) & 7; return h->symbol[index + (code - first)]; } index += count; first += count; first <<= 1; code <<= 1; len++; } left = (MAXBITS + 1) - len; if (left == 0) break; if (s->incnt == s->inlen) longjmp(s->env, 1); bitbuf = s->in[s->incnt++]; if (left > 8) left = 8; } return -10; } static int puff_construct(struct puff_huffman* h, const short* length, int n) { int len; for (len = 0; len <= MAXBITS; len++) h->count[len] = 0; int symbol; for (symbol = 0; symbol < n; symbol++) (h->count[length[symbol]])++; if (h->count[0] == n) return 0; int left = 1; for (len = 1; len <= MAXBITS; len++) { left <<= 1; left -= h->count[len]; if (left < 0) return left; } short offs[MAXBITS + 1]; offs[1] = 0; for (len = 1; len < MAXBITS; len++) offs[len + 1] = offs[len] + h->count[len]; for (symbol = 0; symbol < n; symbol++) if (length[symbol] != 0) h->symbol[offs[length[symbol]]++] = symbol; return left; } static int puff_codes(struct puff_state* s, const struct puff_huffman* lencode, const struct puff_huffman* distcode) { static const short lens[29] = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258}; static const short lext[29] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0}; static const short dists[30] = { 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577}; static const short dext[30] = {0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13}; int symbol; do { symbol = puff_decode(s, lencode); if (symbol < 0) return symbol; if (symbol < 256) { if (s->outcnt == s->outlen) return 1; if (symbol) s->out[s->outcnt] = symbol; s->outcnt++; } else if (symbol > 256) { symbol -= 257; if (symbol >= 29) return -10; int len = lens[symbol] + puff_bits(s, lext[symbol]); symbol = puff_decode(s, distcode); if (symbol < 0) return symbol; unsigned dist = dists[symbol] + puff_bits(s, dext[symbol]); if (dist > s->outcnt) return -11; if (s->outcnt + len > s->outlen) return 1; while (len--) { if (dist <= s->outcnt && s->out[s->outcnt - dist]) s->out[s->outcnt] = s->out[s->outcnt - dist]; s->outcnt++; } } } while (symbol != 256); return 0; } static int puff_fixed(struct puff_state* s) { static int virgin = 1; static short lencnt[MAXBITS + 1], lensym[FIXLCODES]; static short distcnt[MAXBITS + 1], distsym[MAXDCODES]; static struct puff_huffman lencode, distcode; if (virgin) { lencode.count = lencnt; lencode.symbol = lensym; distcode.count = distcnt; distcode.symbol = distsym; short lengths[FIXLCODES]; int symbol; for (symbol = 0; symbol < 144; symbol++) lengths[symbol] = 8; for (; symbol < 256; symbol++) lengths[symbol] = 9; for (; symbol < 280; symbol++) lengths[symbol] = 7; for (; symbol < FIXLCODES; symbol++) lengths[symbol] = 8; puff_construct(&lencode, lengths, FIXLCODES); for (symbol = 0; symbol < MAXDCODES; symbol++) lengths[symbol] = 5; puff_construct(&distcode, lengths, MAXDCODES); virgin = 0; } return puff_codes(s, &lencode, &distcode); } static int puff_dynamic(struct puff_state* s) { static const short order[19] = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; int nlen = puff_bits(s, 5) + 257; int ndist = puff_bits(s, 5) + 1; int ncode = puff_bits(s, 4) + 4; if (nlen > MAXLCODES || ndist > MAXDCODES) return -3; short lengths[MAXCODES]; int index; for (index = 0; index < ncode; index++) lengths[order[index]] = puff_bits(s, 3); for (; index < 19; index++) lengths[order[index]] = 0; short lencnt[MAXBITS + 1], lensym[MAXLCODES]; struct puff_huffman lencode = {lencnt, lensym}; int err = puff_construct(&lencode, lengths, 19); if (err != 0) return -4; index = 0; while (index < nlen + ndist) { int symbol; int len; symbol = puff_decode(s, &lencode); if (symbol < 0) return symbol; if (symbol < 16) lengths[index++] = symbol; else { len = 0; if (symbol == 16) { if (index == 0) return -5; len = lengths[index - 1]; symbol = 3 + puff_bits(s, 2); } else if (symbol == 17) symbol = 3 + puff_bits(s, 3); else symbol = 11 + puff_bits(s, 7); if (index + symbol > nlen + ndist) return -6; while (symbol--) lengths[index++] = len; } } if (lengths[256] == 0) return -9; err = puff_construct(&lencode, lengths, nlen); if (err && (err < 0 || nlen != lencode.count[0] + lencode.count[1])) return -7; short distcnt[MAXBITS + 1], distsym[MAXDCODES]; struct puff_huffman distcode = {distcnt, distsym}; err = puff_construct(&distcode, lengths + nlen, ndist); if (err && (err < 0 || ndist != distcode.count[0] + distcode.count[1])) return -8; return puff_codes(s, &lencode, &distcode); } static int puff(unsigned char* dest, unsigned long* destlen, const unsigned char* source, unsigned long sourcelen) { struct puff_state s = { .out = dest, .outlen = *destlen, .outcnt = 0, .in = source, .inlen = sourcelen, .incnt = 0, .bitbuf = 0, .bitcnt = 0, }; int err; if (setjmp(s.env) != 0) err = 2; else { int last; do { last = puff_bits(&s, 1); int type = puff_bits(&s, 2); err = type == 0 ? puff_stored(&s) : (type == 1 ? puff_fixed(&s) : (type == 2 ? puff_dynamic(&s) : -1)); if (err != 0) break; } while (!last); } *destlen = s.outcnt; return err; } //% END CODE DERIVED FROM puff.{c,h} #define ZLIB_HEADER_WIDTH 2 static int puff_zlib_to_file(const unsigned char* source, unsigned long sourcelen, int dest_fd) { if (sourcelen < ZLIB_HEADER_WIDTH) return 0; source += ZLIB_HEADER_WIDTH; sourcelen -= ZLIB_HEADER_WIDTH; const unsigned long max_destlen = 132 << 20; void* ret = mmap(0, max_destlen, PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANON, -1, 0); if (ret == MAP_FAILED) return -1; unsigned char* dest = (unsigned char*)ret; unsigned long destlen = max_destlen; int err = puff(dest, &destlen, source, sourcelen); if (err) { munmap(dest, max_destlen); errno = -err; return -1; } if (write(dest_fd, dest, destlen) != (ssize_t)destlen) { munmap(dest, max_destlen); return -1; } return munmap(dest, max_destlen); } static int setup_loop_device(unsigned char* data, unsigned long size, const char* loopname, int* loopfd_p) { int err = 0, loopfd = -1; int memfd = syscall(__NR_memfd_create, "syzkaller", 0); if (memfd == -1) { err = errno; goto error; } if (puff_zlib_to_file(data, size, memfd)) { err = errno; goto error_close_memfd; } 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; } } close(memfd); *loopfd_p = loopfd; return 0; error_close_loop: close(loopfd); error_close_memfd: close(memfd); error: errno = err; return -1; } static void reset_loop_device(const char* loopname) { int loopfd = open(loopname, O_RDWR); if (loopfd == -1) { return; } if (ioctl(loopfd, LOOP_CLR_FD, 0)) { } close(loopfd); } static long syz_mount_image(volatile long fsarg, volatile long dir, volatile long flags, volatile long optsarg, volatile long change_dir, volatile unsigned long size, volatile long image) { unsigned char* data = (unsigned char*)image; int res = -1, err = 0, need_loop_device = !!size; char* mount_opts = (char*)optsarg; char* target = (char*)dir; char* fs = (char*)fsarg; char* source = NULL; char loopname[64]; if (need_loop_device) { int loopfd; memset(loopname, 0, sizeof(loopname)); snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid); if (setup_loop_device(data, size, loopname, &loopfd) == -1) return -1; close(loopfd); 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) { bool has_remount_ro = false; char* remount_ro_start = strstr(opts, "errors=remount-ro"); if (remount_ro_start != NULL) { char after = *(remount_ro_start + strlen("errors=remount-ro")); char before = remount_ro_start == opts ? '\0' : *(remount_ro_start - 1); has_remount_ro = ((before == '\0' || before == ',') && (after == '\0' || after == ',')); } if (strstr(opts, "errors=panic") || !has_remount_ro) strcat(opts, ",errors=continue"); } else if (strcmp(fs, "xfs") == 0) { strcat(opts, ",nouuid"); } else if (strncmp(fs, "gfs2", 4) == 0 && (strstr(opts, "errors=panic") || strstr(opts, "debug"))) { strcat(opts, ",errors=withdraw"); } 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; goto error_clear_loop; } if (change_dir) { res = chdir(target); if (res == -1) { err = errno; } } error_clear_loop: if (need_loop_device) reset_loop_device(loopname); errno = err; return res; } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { int iter = 0; DIR* dp = 0; const int umount_flags = MNT_FORCE | UMOUNT_NOFOLLOW; retry: while (umount2(dir, umount_flags) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } struct dirent* ep = 0; while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); while (umount2(filename, umount_flags) == 0) { } struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EPERM) { int fd = open(filename, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exit(1); if (umount2(filename, umount_flags)) exit(1); } } closedir(dp); for (int i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EPERM) { int fd = open(dir, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, umount_flags)) exit(1); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exit(1); } } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void reset_loop() { char buf[64]; snprintf(buf, sizeof(buf), "/dev/loop%llu", procid); int loopfd = open(buf, O_RDWR); if (loopfd != -1) { ioctl(loopfd, LOOP_CLR_FD, 0); close(loopfd); } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); if (symlink("/dev/binderfs", "./binderfs")) { } } static void setup_sysctl() { int cad_pid = fork(); if (cad_pid < 0) exit(1); if (cad_pid == 0) { for (;;) sleep(100); } char tmppid[32]; snprintf(tmppid, sizeof(tmppid), "%d", cad_pid); struct { const char* name; const char* data; } files[] = { {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"}, {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, {"/proc/sys/kernel/ctrl-alt-del", "0"}, {"/proc/sys/kernel/cad_pid", tmppid}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) { } } kill(cad_pid, SIGKILL); while (waitpid(cad_pid, NULL, 0) != cad_pid) ; } struct thread_t { int created, call; event_t ready, done; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { event_wait(&th->ready); event_reset(&th->ready); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); event_set(&th->done); } return 0; } static void execute_one(void) { if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } int i, call, thread; for (call = 0; call < 3; call++) { for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; event_init(&th->ready); event_init(&th->done); event_set(&th->done); thread_start(thr, th); } if (!event_isset(&th->done)) continue; event_reset(&th->done); th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); event_set(&th->ready); event_timedwait(&th->done, 50 + (call == 0 ? 4000 : 0)); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); reset_loop(); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); setup_test(); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { sleep_ms(10); if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } void execute_call(int call) { switch (call) { case 0: // syz_mount_image$ext4 arguments: [ // fs: ptr[in, buffer] { // buffer: {65 78 74 34 00} (length 0x5) // } // dir: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 31 00} (length 0x8) // } // flags: mount_flags = 0x0 (8 bytes) // opts: ptr[in, fs_options[ext4_options]] { // fs_options[ext4_options] { // elems: array[fs_opt_elem[ext4_options]] { // fs_opt_elem[ext4_options] { // elem: union ext4_options { // norecovery: buffer: {6e 6f 72 65 63 6f 76 65 72 79} (length // 0xa) // } // comma: const = 0x2c (1 bytes) // } // fs_opt_elem[ext4_options] { // elem: union ext4_options { // debug_want_extra_isize: fs_opt["debug_want_extra_isize", // fmt[hex, int32]] { // name: buffer: {64 65 62 75 67 5f 77 61 6e 74 5f 65 78 74 // 72 61 5f 69 73 69 7a 65} (length 0x16) eq: const = 0x3d (1 // bytes) val: int32 = 0x3e (18 bytes) // } // } // comma: const = 0x2c (1 bytes) // } // } // common: array[fs_opt_elem[fs_options_common]] { // } // null: const = 0x0 (1 bytes) // } // } // chdir: int8 = 0x1 (1 bytes) // size: len = 0x603 (8 bytes) // img: ptr[in, buffer] { // buffer: (compressed buffer with length 0x603) // } // ] // returns fd_dir NONFAILING(memcpy((void*)0x200000000600, "ext4\000", 5)); NONFAILING(memcpy((void*)0x200000000640, "./file1\000", 8)); NONFAILING(memcpy((void*)0x200000000080, "norecovery", 10)); NONFAILING(*(uint8_t*)0x20000000008a = 0x2c); NONFAILING(memcpy((void*)0x20000000008b, "debug_want_extra_isize", 22)); NONFAILING(*(uint8_t*)0x2000000000a1 = 0x3d); NONFAILING(sprintf((char*)0x2000000000a2, "0x%016llx", (long long)0x3e)); NONFAILING(*(uint8_t*)0x2000000000b4 = 0x2c); NONFAILING(*(uint8_t*)0x2000000000b5 = 0); NONFAILING(memcpy( (void*)0x200000000d80, "\x78\x9c\xec\xdd\xcd\x6f\x14\xe7\x19\x00\xf0\x67\x66\xb1\xc1\xc6\xad" "\x41\xf2\xa1\xf4\x52\x57\x3d\x80\x54\x75\xfd\xd5\x0a\xe8\xa5\xa0\xb6" "\xa7\x16\x41\x69\xd5\x5e\x2a\x51\x17\xd6\x1f\x62\xed\x75\xfd\x21\x61" "\xf7\x62\x38\x58\xea\xad\x95\x2a\xf5\xd6\x36\x87\x1c\x72\xb3\xf2\x07" "\x24\x1c\xf2\x07\x24\xb7\x44\x89\x94\x2b\x8a\x84\x88\x42\x0e\x91\x38" "\x38\x9a\xfd\xb0\x8d\xbd\x1b\x3b\x60\x3c\xd8\xf3\xfb\x49\xe3\x9d\x77" "\xde\x9d\x7d\xdf\xd9\x67\x9f\xdd\x9d\x17\xde\xd9\x00\x0a\x6b\x30\xfb" "\x93\x46\x9c\x8b\x88\x2b\x49\x44\xff\xb6\xba\x13\xd1\xac\x1c\x6c\xdc" "\x6f\x6d\x6c\x7d\x2a\x5b\x92\xd8\x28\xfd\xfe\x49\x12\x49\x44\x2c\x8d" "\xad\x4f\xb5\xee\x9f\x34\x6f\x4f\x37\x77\xbb\x10\x11\x37\x7f\x1d\x71" "\xb3\xb4\xbb\xdd\x85\xe5\x95\xbb\xe3\xd5\x6a\x65\xbe\x59\x1e\x5a\x9c" "\x99\x1b\x5a\x58\x5e\xf9\xc9\xf4\xcc\xf8\x64\x65\xb2\x32\x3b\x76\x69" "\xe4\xf2\xa5\xb1\x9f\x5d\xbc\x38\x72\x60\xc7\xfa\xbb\x27\x7d\xef\x3f" "\xfa\xdf\xf5\x81\xb7\x7f\xfa\xdf\x3f\x4f\xfc\xfd\xad\x95\xac\xbf\x7d" "\xcd\xba\xed\xc7\x71\x50\x06\x63\xb0\xf9\x9c\x74\xc5\x95\x1d\x75\x3b" "\xcb\x47\x55\xa9\xf9\x3a\x49\xf3\xee\x08\x2f\xa4\x15\xbf\xae\x88\x18" "\x88\xfe\x28\x35\xb3\x3e\xd3\x1f\xcf\x3e\xc9\xb5\x73\xc0\x2b\xb5\xd1" "\x1f\xb1\xb1\x53\xf6\xa1\xb5\x6b\xe3\x73\x7a\x5a\xbb\x03\x47\x59\x22" "\x89\xa1\xa0\x5a\xdf\x03\xb2\xf3\xdf\xd6\x92\xdf\xb7\x11\x0e\xdb\xe3" "\xab\x8d\x13\xc0\xa5\xe6\xd8\xce\xda\x66\xfc\x4f\x34\xc6\x86\xe2\x54" "\xbc\x77\x32\xa2\xf7\x69\xb2\xed\xcc\xb0\x31\xd6\x33\x78\x00\xed\x67" "\x8f\x71\x65\xf0\x4f\xef\x64\x4b\xbc\xa2\x71\x18\x3a\x5b\xbd\x1f\x11" "\xdf\x6b\x97\xff\x49\x3d\x36\x67\xe2\x54\xbd\xd4\xfb\x34\x7d\x2e\xfe" "\x69\x44\xdc\x68\xde\x66\xdb\x6f\xbe\x60\xfb\x3b\x5f\x43\xe2\x7f\xb8" "\x5e\x26\xfe\x7f\xd9\x16\xff\xbf\xbe\x60\xfb\xe2\x0f\x00\x00\x70\x38" "\x1e\x5e\x8d\x88\xe1\x76\xe7\x7f\xe9\xe6\xf8\x4f\xc4\xee\xf1\x9f\xbe" "\xc6\x6e\x2f\xcd\xf9\x5f\xbe\x5a\xe3\x7f\x6b\xbb\xc6\xff\xb6\xe2\x5f" "\x6a\x13\xff\x24\x22\xe6\xf6\xd9\xc6\xf5\x0f\xfe\xf5\xc3\x4e\x75\xdb" "\xc7\xff\xb2\x25\x6b\xbf\x35\x16\xc8\xab\xf7\xf8\x7e\xc4\xf7\xdb\xc6" "\x3f\xd9\x8c\x7f\xd2\x26\xfe\x69\x44\xac\xee\xb3\x8d\x8f\xcf\xfe\x67" "\xa0\x53\x5d\xa7\xf8\xaf\xbc\xd4\x51\xb1\x5f\x1b\x6f\x44\x9c\x8f\xf6" "\xf1\x6f\x49\xbe\xf9\xff\x67\x0e\x4d\x4c\x57\x2b\xc3\x8d\xbf\x6d\xdb" "\x78\xf6\xc7\x47\x6f\x76\x6a\x5f\xfe\xe7\x2b\xcb\xff\xde\x0e\xf1\xdf" "\xeb\xfd\xff\x9f\xfb\x6c\xa3\xfa\x8f\x2f\xfa\x76\x6f\xdd\x7a\xb4\x56" "\xec\x57\x7f\xf5\x9b\x77\x77\xc7\x3f\xfd\xac\x3b\xf9\x43\xfd\xc5\xd8" "\xdd\xdc\x72\x6f\x7c\x71\x71\x7e\x24\xa2\x3b\xf9\xed\xee\xed\xa3\xdf" "\xe6\xe8\x8b\xa7\xf5\x1c\xb5\x9e\xc3\x2c\xfe\x17\x7e\xf4\xac\xf9\xaf" "\xc1\xed\x3f\xff\xdb\xbd\xff\xf7\x44\xc4\xff\xf7\xd9\xe6\x83\x4f\x7f" "\xf9\x55\xa7\x3a\xf9\x9f\xaf\x2c\xfe\x77\xf6\xc8\xff\x76\xf1\xcf\xb6" "\xad\xef\xb3\x8d\xcf\x1f\xfc\xad\xe3\xc7\xf9\xe0\x9e\xf9\x0f\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xc7" "\x47\x5a\xbf\x96\x6f\x92\x96\x37\xd7\xd3\xb4\x5c\x6e\xfc\x86\xf7\x40" "\xf4\xa6\xd5\xda\xc2\xe2\x8f\x27\x6a\x4b\xb3\x77\x1a\xd7\xfc\x3d\x13" "\x5d\x69\xeb\x4a\x8f\xfd\x8d\x72\x92\x95\x47\xea\xeb\x5b\xe5\xd1\x1d" "\xe5\xb1\x88\x38\x1b\x11\xff\x2e\xf5\xd4\xcb\xe5\xdb\xb5\xea\x9d\xbc" "\x0f\x1e\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x5e\x13\xa7\x77\xcc\xff\xff\xb2\xd4\x98\xff\x0f\x14\xc4\x89\xbc\x3b" "\x00\xe4\x46\xfe\x43\x71\xc9\x7f\x28\x2e\xf9\x0f\xc5\x25\xff\xa1\xb8" "\xe4\x3f\x14\x97\xfc\x87\xe2\x92\xff\x50\x5c\xf2\x1f\x8a\x4b\xfe\x43" "\x71\xc9\x7f\x00\x00\x00\x00\x38\x96\x6e\x5c\xbb\x96\x2d\x1b\x6b\x63" "\xeb\x53\x59\x79\xb6\x36\x39\x7d\x77\x6a\xee\xf2\xe8\x70\x79\x66\xe9" "\x76\xf9\x76\x6d\x7e\xae\x3c\x59\xab\x4d\xd6\x7f\xb1\x7f\x66\xef\xc7" "\xab\xd6\x6a\x73\x23\xa3\xb1\x74\x6f\x68\xb1\xb2\xb0\x38\xb4\xb0\xbc" "\x72\x6b\xa6\xb6\x34\xbb\x78\x6b\x7a\x66\x7c\xb2\x72\xab\xd2\x75\x08" "\xc7\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x47\xcd\xd9\x1f\x3c\xfc\x28\x89\x88\xd5\x9f\xf7\xd4\x97\x4c\x77\xb3" "\xce\x5c\x7d\x38\xde\xd2\xbc\x3b\x00\xe4\xa6\x94\x77\x07\x80\xdc\xb8" "\xf4\x3f\x14\x97\x73\x7c\x20\xd9\xa3\xfe\x54\xa7\x8a\x87\x7b\xed\x09" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x1c\x94\xf3\xe7\xcc\xff\x87" "\xa2\x32\xff\x1f\x8a\xcb\xfc\x7f\x28\x2e\xf3\xff\xa1\xb8\x3a\x9d\xe3" "\x9f\x3c\xe4\x7e\x00\xf9\x31\xff\x1f\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x5e\x7f\x7d\xf5\x25\x49\xcb\xcd\xb9\xc0\x7d\x91\xa6\xe5\x72" "\xc4\x77\x22\xe2\x4c\x74\x25\x13\xd3\xd5\xca\x70\x44\x7c\x37\x22\x3e" "\x2c\x75\x9d\xcc\xca\x23\x79\x77\x1a\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x8e\x99\x85\xe5\x95\xbb\xe3\xd5\x6a\x65" "\x3e\xd7\x95\x5f\x34\x7b\x93\x73\x37\xac\x58\x79\xad\x56\x4a\x11\x91" "\x57\xeb\x39\xbf\x31\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x40\x01\x6d\x4d\xfa\xcd\xbb\x27\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x90\x9f\xad\xdf\xff\x3f\x98\x95\xee\x36" "\x55\x79\x1f\x23\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xc0\x51\xf4\x75" "\x00\x00\x00\xff\xff\x86\xf0\xf3\x59", 1539)); NONFAILING(syz_mount_image(/*fs=*/0x200000000600, /*dir=*/0x200000000640, /*flags=*/0, /*opts=*/0x200000000080, /*chdir=*/1, /*size=*/0x603, /*img=*/0x200000000d80)); break; case 1: // lchown arguments: [ // file: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 31 00} (length 0x8) // } // uid: uid (resource) // gid: gid (resource) // ] NONFAILING(memcpy((void*)0x200000001600, "./file1\000", 8)); syscall(__NR_lchown, /*file=*/0x200000001600ul, /*uid=*/0, /*gid=*/0); break; case 2: // lsetxattr$trusted_overlay_upper arguments: [ // path: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 31 00} (length 0x8) // } // name: ptr[in, buffer] { // buffer: {74 72 75 73 74 65 64 2e 6f 76 65 72 6c 61 79 2e 75 70 70 65 // 72 00} (length 0x16) // } // val: ptr[inout, array[ANYUNION]] { // array[ANYUNION] { // } // } // size: len = 0xe1 (8 bytes) // flags: setxattr_flags = 0x0 (8 bytes) // ] NONFAILING(memcpy((void*)0x200000000700, "./file1\000", 8)); NONFAILING(memcpy((void*)0x200000000740, "trusted.overlay.upper\000", 22)); syscall(__NR_lsetxattr, /*path=*/0x200000000700ul, /*name=*/0x200000000740ul, /*val=*/0x200000000f40ul, /*size=*/0xe1ul, /*flags=*/0ul); break; } } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); setup_sysctl(); const char* reason; (void)reason; install_segv_handler(); use_temporary_dir(); loop(); return 0; }