// 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 __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include const int kFailStatus = 67; const int kRetryStatus = 69; 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); } static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { char buf[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf)); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 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) { close(fd); return false; } close(fd); return true; } 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 test(); void loop() { while (1) { test(); } } #ifndef __NR_mmap #define __NR_mmap 192 #endif #ifndef __NR_memfd_create #define __NR_memfd_create 356 #endif #ifndef __NR_pwritev #define __NR_pwritev 334 #endif #ifndef __NR_ioctl #define __NR_ioctl 54 #endif #undef __NR_mmap #define __NR_mmap __NR_mmap2 long r[2]; void test() { memset(r, -1, sizeof(r)); syscall(__NR_mmap, 0x20000000, 0xfff000, 0x3, 0x32, 0xffffffff, 0x0); memcpy((void*)0x2040aff5, "/dev/loop#", 11); r[0] = syz_open_dev(0x2040aff5, 0x0, 0x0); memcpy((void*)0x20614000, "\x74\x75\x6e\x08\x00\x00\x00\x00\x00\x00" "\x00\x80\x00\x00\x00\x00", 16); r[1] = syscall(__NR_memfd_create, 0x20614000, 0x0); *(uint32_t*)0x20ba2f60 = 0x20a94000; *(uint32_t*)0x20ba2f64 = 0x0; syscall(__NR_pwritev, r[1], 0x20ba2f60, 0x1, 0x49); syscall(__NR_ioctl, r[0], 0x4c01); write_file("/sys/kernel/debug/failslab/ignore-gfp-wait", "N"); write_file("/sys/kernel/debug/fail_futex/ignore-private", "N"); inject_fault(2); syscall(__NR_ioctl, r[0], 0x4c00, r[1]); } int main() { loop(); return 0; }