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Kernel: Randomize non-specific VM allocations done by sys$execve()

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Stuff like TLS regions, main thread stacks, etc. All deserve to be
randomized unless the ELF requires specific placement. :^)
This commit is contained in:
Andreas Kling 2022-04-03 23:32:03 +02:00
parent 10b2b71a2c
commit 9250ac0c24
1 changed files with 5 additions and 5 deletions
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10
Kernel/Syscalls/execve.cpp
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@ -295,7 +295,7 @@ static ErrorOr<LoadResult> load_elf_object(NonnullOwnPtr<Memory::AddressSpace> n
}
auto region_name = TRY(KString::formatted("{} (master-tls)", elf_name));
master_tls_region = TRY(new_space->allocate_region(Memory::RandomizeVirtualAddress::No, {}, program_header.size_in_memory(), PAGE_SIZE, region_name->view(), PROT_READ | PROT_WRITE, AllocationStrategy::Reserve));
master_tls_region = TRY(new_space->allocate_region(Memory::RandomizeVirtualAddress::Yes, {}, program_header.size_in_memory(), PAGE_SIZE, region_name->view(), PROT_READ | PROT_WRITE, AllocationStrategy::Reserve));
master_tls_size = program_header.size_in_memory();
master_tls_alignment = program_header.alignment();
@ -323,7 +323,7 @@ static ErrorOr<LoadResult> load_elf_object(NonnullOwnPtr<Memory::AddressSpace> n
size_t rounded_range_end = TRY(Memory::page_round_up(program_header.vaddr().offset(load_offset).offset(program_header.size_in_memory()).get()));
auto range_end = VirtualAddress { rounded_range_end };
auto region = TRY(new_space->allocate_region(Memory::RandomizeVirtualAddress::No, range_base, range_end.get() - range_base.get(), PAGE_SIZE, region_name->view(), prot, AllocationStrategy::Reserve));
auto region = TRY(new_space->allocate_region(Memory::RandomizeVirtualAddress::Yes, range_base, range_end.get() - range_base.get(), PAGE_SIZE, region_name->view(), prot, AllocationStrategy::Reserve));
// It's not always the case with PIE executables (and very well shouldn't be) that the
// virtual address in the program header matches the one we end up giving the process.
@ -358,7 +358,7 @@ static ErrorOr<LoadResult> load_elf_object(NonnullOwnPtr<Memory::AddressSpace> n
auto range_base = VirtualAddress { Memory::page_round_down(program_header.vaddr().offset(load_offset).get()) };
size_t rounded_range_end = TRY(Memory::page_round_up(program_header.vaddr().offset(load_offset).offset(program_header.size_in_memory()).get()));
auto range_end = VirtualAddress { rounded_range_end };
auto region = TRY(new_space->allocate_region_with_vmobject(Memory::RandomizeVirtualAddress::No, range_base, range_end.get() - range_base.get(), program_header.alignment(), *vmobject, program_header.offset(), elf_name->view(), prot, true));
auto region = TRY(new_space->allocate_region_with_vmobject(Memory::RandomizeVirtualAddress::Yes, range_base, range_end.get() - range_base.get(), program_header.alignment(), *vmobject, program_header.offset(), elf_name->view(), prot, true));
if (should_allow_syscalls == ShouldAllowSyscalls::Yes)
region->set_syscall_region(true);
@ -392,7 +392,7 @@ static ErrorOr<LoadResult> load_elf_object(NonnullOwnPtr<Memory::AddressSpace> n
return ENOEXEC;
}
auto* stack_region = TRY(new_space->allocate_region(Memory::RandomizeVirtualAddress::No, {}, Thread::default_userspace_stack_size, PAGE_SIZE, "Stack (Main thread)", PROT_READ | PROT_WRITE, AllocationStrategy::Reserve));
auto* stack_region = TRY(new_space->allocate_region(Memory::RandomizeVirtualAddress::Yes, {}, Thread::default_userspace_stack_size, PAGE_SIZE, "Stack (Main thread)", PROT_READ | PROT_WRITE, AllocationStrategy::Reserve));
stack_region->set_stack(true);
return LoadResult {
@ -469,7 +469,7 @@ ErrorOr<void> Process::do_exec(NonnullRefPtr<OpenFileDescription> main_program_d
bool has_interpreter = interpreter_description;
interpreter_description = nullptr;
auto* signal_trampoline_region = TRY(load_result.space->allocate_region_with_vmobject(Memory::RandomizeVirtualAddress::No, {}, PAGE_SIZE, PAGE_SIZE, g_signal_trampoline_region->vmobject(), 0, "Signal trampoline", PROT_READ | PROT_EXEC, true));
auto* signal_trampoline_region = TRY(load_result.space->allocate_region_with_vmobject(Memory::RandomizeVirtualAddress::Yes, {}, PAGE_SIZE, PAGE_SIZE, g_signal_trampoline_region->vmobject(), 0, "Signal trampoline", PROT_READ | PROT_EXEC, true));
signal_trampoline_region->set_syscall_region(true);
// (For dynamically linked executable) Allocate an FD for passing the main executable to the dynamic loader.