// https://syzkaller.appspot.com/bug?id=cdb658d8cbeff62a4d998e94be26bd578507e32c // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #ifndef __NR_add_key #define __NR_add_key 286 #endif #ifndef __NR_getsockopt #define __NR_getsockopt 365 #endif #ifndef __NR_mkdirat #define __NR_mkdirat 296 #endif #ifndef __NR_mmap #define __NR_mmap 192 #endif #ifndef __NR_mount #define __NR_mount 21 #endif #ifndef __NR_open #define __NR_open 5 #endif #undef __NR_mmap #define __NR_mmap __NR_mmap2 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; \ }) uint64_t r[1] = {0xffffffffffffffff}; int main(void) { syscall(__NR_mmap, /*addr=*/0x7ffff000, /*len=*/0x1000, /*prot=*/0, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32, /*fd=*/(intptr_t)-1, /*offset=*/0); syscall(__NR_mmap, /*addr=*/0x80000000, /*len=*/0x1000000, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32, /*fd=*/(intptr_t)-1, /*offset=*/0); syscall(__NR_mmap, /*addr=*/0x81000000, /*len=*/0x1000, /*prot=*/0, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32, /*fd=*/(intptr_t)-1, /*offset=*/0); const char* reason; (void)reason; install_segv_handler(); intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // mkdirat arguments: [ // fd: fd_dir (resource) // path: ptr[in, buffer] { // buffer: {2e 2f 6d 6e 74 00} (length 0x6) // } // mode: open_mode = 0x1ff (4 bytes) // ] NONFAILING(memcpy((void*)0x80004000, "./mnt\000", 6)); syscall( __NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x80004000, /*mode=S_IXOTH|S_IWOTH|S_IROTH|S_IXGRP|S_IWGRP|S_IRGRP|S_IXUSR|S_IWUSR|0x100*/ 0x1ff); // getsockopt$TIPC_DEST_DROPPABLE arguments: [ // fd: sock_tipc (resource) // level: const = 0x10f (4 bytes) // opt: const = 0x81 (4 bytes) // val: ptr[out, int32] { // int32 = 0x0 (4 bytes) // } // len: ptr[inout, bytesize] { // bytesize = 0x4 (4 bytes) // } // ] NONFAILING(*(uint32_t*)0x800000c0 = 4); syscall(__NR_getsockopt, /*fd=*/(intptr_t)-1, /*level=*/0x10f, /*opt=*/0x81, /*val=*/0x80000080, /*len=*/0x800000c0); // add_key$user arguments: [ // type: ptr[in, buffer] { // buffer: {75 73 65 72 00} (length 0x5) // } // desc: ptr[in, key_desc] { // key_desc { // prefix: buffer: {73 79 7a} (length 0x3) // id: proc = 0xffffffffffffffff (1 bytes) // z: const = 0x0 (1 bytes) // } // } // payload: ptr[in, buffer] { // buffer: {} (length 0x0) // } // paylen: len = 0xc9 (4 bytes) // keyring: keyring (resource) // ] // returns user_key NONFAILING(memcpy((void*)0x800003c0, "user\000", 5)); NONFAILING(memcpy((void*)0x80000440, "syz", 3)); NONFAILING(*(uint8_t*)0x80000443 = 0); NONFAILING(*(uint8_t*)0x80000444 = 0); syscall(__NR_add_key, /*type=*/0x800003c0, /*desc=*/0x80000440, /*payload=*/0x800000c0, /*paylen=*/0xc9, /*keyring=*/0xfffffffd); // mount arguments: [ // src: ptr[in, blockdev_filename] { // union blockdev_filename { // filename: buffer: {00} (length 0x1) // } // } // dst: ptr[in, buffer] { // buffer: {2e 2f 6d 6e 74 00} (length 0x6) // } // type: ptr[in, buffer] { // buffer: {65 63 72 79 70 74 66 73 00} (length 0x9) // } // flags: mount_flags = 0x0 (4 bytes) // data: ptr[in, buffer] { // buffer: {65 63 72 79 70 74 66 73 5f 73 69 67 3d 73 79 7a 2c 65 63 72 // 79 70 74 66 73 5f 66 6e 65 6b 5f 73 69 67 3d 73 79 7a 2c 65 63 72 79 // 70 74 66 73 5f 63 69 70 68 65 72 3d 61 65 73 2c 65 63 72 79 70 74 66 // 73 5f 6b 65 79 5f 62 79 74 65 73 3d 31 36 00} (length 0x51) // } // ] NONFAILING(memset((void*)0x80000400, 0, 1)); NONFAILING(memcpy((void*)0x80000000, "./mnt\000", 6)); NONFAILING(memcpy((void*)0x80000480, "ecryptfs\000", 9)); NONFAILING(memcpy((void*)0x80000500, "ecryptfs_sig=syz,ecryptfs_fnek_sig=syz,ecryptfs_cipher=" "aes,ecryptfs_key_bytes=16\000", 81)); syscall(__NR_mount, /*src=*/0x80000400, /*dst=*/0x80000000, /*type=*/0x80000480, /*flags=*/0, /*data=*/0x80000500); // open arguments: [ // file: ptr[in, buffer] { // buffer: {2e 2f 6d 6e 74 00} (length 0x6) // } // flags: open_flags = 0x8000 (4 bytes) // mode: open_mode = 0x129 (4 bytes) // ] // returns fd NONFAILING(memcpy((void*)0x800001c0, "./mnt\000", 6)); res = syscall(__NR_open, /*file=*/0x800001c0, /*flags=O_LARGEFILE*/ 0x8000, /*mode=S_IXOTH|S_IXGRP|S_IRGRP|S_IRUSR*/ 0x129); if (res != -1) r[0] = res; // mkdirat arguments: [ // fd: fd_dir (resource) // path: ptr[in, buffer] { // buffer: {2e 2f 6d 6e 74 00} (length 0x6) // } // mode: open_mode = 0x343806076c12c449 (4 bytes) // ] NONFAILING(memcpy((void*)0x80000240, "./mnt\000", 6)); syscall(__NR_mkdirat, /*fd=*/(intptr_t)r[0], /*path=*/0x80000240, /*mode=S_IXOTH|S_IXGRP|S_IXUSR|0x6c12c400*/ 0x6c12c449); return 0; }