/* Copyright (C) 2024-2025 anonymous This file is part of PSFree. PSFree is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. PSFree 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 Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see . */ // 9.03, 9.04 #include "types.h" #include "utils.h" struct kexec_args { u64 entry; u64 arg1; u64 arg2; u64 arg3; u64 arg4; u64 arg5; }; static inline void restore(void *kbase, struct kexec_args *uap); static inline void patch_aio(void *kbase); static inline void do_patch(void *kbase); __attribute__((section (".text.start"))) int kpatch(void *td, struct kexec_args *uap) { const u64 xfast_syscall_off = 0x1c0; void * const kbase = (void *)rdmsr(0xc0000082) - xfast_syscall_off; do_patch(kbase); patch_aio(kbase); restore(kbase, uap); return 0; } __attribute__((always_inline)) static inline void restore(void *kbase, struct kexec_args *uap) { u8 *pipe = uap->arg1; u8 *pipebuf = uap->arg2; for (int i = 0; i < 0x18; i++) { pipe[i] = pipebuf[i]; } u64 *pktinfo_field = uap->arg3; *pktinfo_field = 0; u64 *pktinfo_field2 = uap->arg4; *pktinfo_field2 = 0; u64 *sysent_661_save = uap->arg5; for (int i = 0; i < 0x30; i += 8) { write64(kbase, 0x1103f00 + i, sysent_661_save[i / 8]); } } __attribute__((always_inline)) static inline void patch_aio(void *kbase) { disable_cr0_wp(); const u64 aio_off = 0x413971; // patch = {0xeb, 0x48} write16(kbase, aio_off, 0x48eb); // offset = 0x42 // patch = {0xeb, 0x06} write16(kbase, aio_off + 0x42, 0x06eb); // offset = 0x4a // patch = {0x41, 0x83, 0xbf, 0xa0, 0x04, 0x00, 0x00, 0x00} write64(kbase, aio_off + 0x4a, 0x00000004a0bf8341); // offset = 0x58 // patch = {0x49, 0x8b, 0x87, 0xd0, 0x04, 0x00, 0x00} write32(kbase, aio_off + 0x58, 0xd0878b49); write16(kbase, aio_off + 0x5c, 0x0004); write8(kbase, aio_off + 0x5e, 0x00); // offset = 0x65 // patch = {0x49, 0x8b, 0xb7, 0xb0, 0x04, 0x00, 0x00} write32(kbase, aio_off + 0x65, 0xb0b78b49); write16(kbase, aio_off + 0x69, 0x0004); write8(kbase, aio_off + 0x6b, 0x00); // offset = 0x7d // patch = {0x49, 0x8b, 0x87, 0x40, 0x05, 0x00, 0x00} write32(kbase, aio_off + 0x7d, 0x40878b49); write16(kbase, aio_off + 0x81, 0x0005); write8(kbase, aio_off + 0x83, 0x00); // offset = 0x8a // patch = {0x49, 0x8b, 0xb7, 0x20, 0x05, 0x00, 0x00} write32(kbase, aio_off + 0x8a, 0x20b78b49); write16(kbase, aio_off + 0x8e, 0x0005); write8(kbase, aio_off + 0x90, 0x00); // offset = 0xa2 // patch = {0x49, 0x8d, 0xbf, 0xc0, 0x00, 0x00, 0x00} write32(kbase, aio_off + 0xa2, 0xc0bf8d49); write16(kbase, aio_off + 0xa6, 0x0000); write8(kbase, aio_off + 0xa8, 0x00); // offset = 0xae // patch = {0x49, 0x8d, 0xbf, 0xe0, 0x00, 0x00, 0x00} write32(kbase, aio_off + 0xae, 0xe0bf8d49); write16(kbase, aio_off + 0xb2, 0x0000); write8(kbase, aio_off + 0xb4, 0x00); // offset = 0xc1 // patch = {0x49, 0x8d, 0xbf, 0x00, 0x01, 0x00, 0x00} write32(kbase, aio_off + 0xc1, 0x00bf8d49); write16(kbase, aio_off + 0xc5, 0x0001); write8(kbase, aio_off + 0xc7, 0x00); // offset = 0xcd // patch = {0x49, 0x8d, 0xbf, 0x20, 0x01, 0x00, 0x00} write32(kbase, aio_off + 0xcd, 0x20bf8d49); write16(kbase, aio_off + 0xd1, 0x0001); write8(kbase, aio_off + 0xd3, 0x00); // offset = 0xde // patch = {0x49, 0x8b, 0xff} write16(kbase, aio_off + 0xde, 0x8b49); write8(kbase, aio_off + 0xe0, 0xff); enable_cr0_wp(); } __attribute__((always_inline)) static inline void do_patch(void *kbase) { disable_cr0_wp(); // ChendoChap's patches from pOOBs4 write16(kbase, 0x624834, 0x00eb); // veriPatch write8(kbase, 0xacd, 0xeb); // bcopy write8(kbase, 0x27107d, 0xeb); // bzero write8(kbase, 0x2710c1, 0xeb); // pagezero write8(kbase, 0x27113d, 0xeb); // memcpy write8(kbase, 0x271181, 0xeb); // pagecopy write8(kbase, 0x27132d, 0xeb); // copyin write8(kbase, 0x2717dd, 0xeb); // copyinstr write8(kbase, 0x2718ad, 0xeb); // copystr // stop sysVeri from causing a delayed panic on suspend write16(kbase, 0x62511f, 0x00eb); // patch amd64_syscall() to allow calling syscalls everywhere // struct syscall_args sa; // initialized already // u64 code = get_u64_at_user_address(td->tf_frame-tf_rip); // int is_invalid_syscall = 0 // // // check the calling code if it looks like one of the syscall stubs at a // // libkernel library and check if the syscall number correponds to the // // proper stub // if ((code & 0xff0000000000ffff) != 0x890000000000c0c7 // || sa.code != (u32)(code >> 0x10) // ) { // // patch this to " = 0" instead // is_invalid_syscall = -1; // } write32(kbase, 0x490, 0); // these code corresponds to the check that ensures that the caller's // instruction pointer is inside the libkernel library's memory range // // // patch the check to always go to the "goto do_syscall;" line // void *code = td->td_frame->tf_rip; // if (libkernel->start <= code && code < libkernel->end // && is_invalid_syscall == 0 // ) { // goto do_syscall; // } // // do_syscall: // ... // lea rsi, [rbp - 0x78] // mov rdi, rbx // mov rax, qword [rbp - 0x80] // call qword [rax + 8] ; error = (sa->callp->sy_call)(td, sa->args) // // sy_call() is the function that will execute the requested syscall. write8(kbase, 0x4c2, 0xeb); write16(kbase, 0x4b9, 0x00eb); write16(kbase, 0x4b5, 0x00eb); // patch sys_setuid() to allow freely changing the effective user ID // ; PRIV_CRED_SETUID = 50 // call priv_check_cred(oldcred, PRIV_CRED_SETUID, 0) // test eax, eax // je ... ; patch je to jmp write8(kbase, 0x1a06, 0xeb); // patch vm_map_protect() (called by sys_mprotect()) to allow rwx mappings // // this check is skipped after the patch // // if ((new_prot & current->max_protection) != new_prot) { // vm_map_unlock(map); // return (KERN_PROTECTION_FAILURE); // } write16(kbase, 0x80b8b, 0x04eb); // TODO: Description of this patch. patch sys_dynlib_load_prx() write16(kbase, 0x23ab94, 0xe990); // patch sys_dynlib_dlsym() to allow dynamic symbol resolution everywhere // call ... // mov r14, qword [rbp - 0xad0] // cmp eax, 0x4000000 // jb ... ; patch jb to jmp write8(kbase, 0x23b34f, 0xeb); // patch called function to always return 0 // // sys_dynlib_dlsym: // ... // mov edi, 0x10 ; 16 // call patched_function ; kernel_base + 0x951c0 // test eax, eax // je ... // mov rax, qword [rbp - 0xad8] // ... // patched_function: ; patch to "xor eax, eax; ret" // push rbp // mov rbp, rsp // ... write32(kbase, 0x221810, 0xc3c03148); // patch sys_mmap() to allow rwx mappings // patch maximum cpu mem protection: 0x33 -> 0x37 // the ps4 added custom protections for their gpu memory accesses // GPU X: 0x8 R: 0x10 W: 0x20 // that's why you see other bits set // ref: https://cturt.github.io/ps4-2.html write8(kbase, 0x1662da, 0x37); write8(kbase, 0x1662dd, 0x37); // overwrite the entry of syscall 11 (unimplemented) in sysent // // struct args { // u64 rdi; // u64 rsi; // u64 rdx; // u64 rcx; // u64 r8; // u64 r9; // }; // // int sys_kexec(struct thread td, struct args *uap) { // asm("jmp qword ptr [rsi]"); // } const u64 sysent_11_off = 0x10fc520; // .sy_narg = 2 write32(kbase, sysent_11_off, 2); // .sy_call = gadgets['jmp qword ptr [rsi]'] write64(kbase, sysent_11_off + 8, kbase + 0x5325b); // .sy_thrcnt = SY_THR_STATIC write32(kbase, sysent_11_off + 0x2c, 1); enable_cr0_wp(); }