mirror of
https://github.com/SerenityOS/serenity
synced 2024-10-16 21:04:20 +00:00
d4b65f644e
From now on, we don't allow jailed processes to open all device nodes in /dev, but only allow jailed processes to open /dev/full, /dev/zero, /dev/null, and various TTY and PTY devices (and not including virtual consoles) so we basically restrict applications to what they can do when they are in jail. The motivation for this type of restriction is to ensure that even if a remote code execution occurred, the damage that can be done is very small. We also don't restrict reading and writing on device nodes that were already opened, because that limit seems not useful, especially in the case where we do want to provide an OpenFileDescription to such device but nothing further than that.
133 lines
4.2 KiB
C++
133 lines
4.2 KiB
C++
/*
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* Copyright (c) 2021, Patrick Meyer <git@the-space.agency>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <AK/Assertions.h>
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#include <AK/NonnullOwnPtr.h>
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#include <Kernel/Devices/DeviceManagement.h>
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#include <Kernel/Devices/KCOVDevice.h>
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#include <Kernel/Devices/KCOVInstance.h>
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#include <Kernel/FileSystem/OpenFileDescription.h>
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#include <LibC/sys/ioctl_numbers.h>
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#include <Kernel/Panic.h>
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namespace Kernel {
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HashMap<ProcessID, KCOVInstance*>* KCOVDevice::proc_instance;
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HashMap<ThreadID, KCOVInstance*>* KCOVDevice::thread_instance;
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UNMAP_AFTER_INIT NonnullLockRefPtr<KCOVDevice> KCOVDevice::must_create()
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{
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auto kcov_device_or_error = DeviceManagement::try_create_device<KCOVDevice>();
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// FIXME: Find a way to propagate errors
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VERIFY(!kcov_device_or_error.is_error());
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return kcov_device_or_error.release_value();
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}
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UNMAP_AFTER_INIT KCOVDevice::KCOVDevice()
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: CharacterDevice(30, 0)
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{
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proc_instance = new HashMap<ProcessID, KCOVInstance*>();
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thread_instance = new HashMap<ThreadID, KCOVInstance*>();
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dbgln("KCOVDevice created");
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}
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void KCOVDevice::free_thread()
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{
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auto thread = Thread::current();
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auto tid = thread->tid();
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auto maybe_kcov_instance = thread_instance->get(tid);
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if (!maybe_kcov_instance.has_value())
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return;
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auto kcov_instance = maybe_kcov_instance.value();
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VERIFY(kcov_instance->state() == KCOVInstance::TRACING);
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kcov_instance->set_state(KCOVInstance::OPENED);
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thread_instance->remove(tid);
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}
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void KCOVDevice::free_process()
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{
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auto pid = Process::current().pid();
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auto maybe_kcov_instance = proc_instance->get(pid);
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if (!maybe_kcov_instance.has_value())
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return;
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auto kcov_instance = maybe_kcov_instance.value();
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VERIFY(kcov_instance->state() == KCOVInstance::OPENED);
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kcov_instance->set_state(KCOVInstance::UNUSED);
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proc_instance->remove(pid);
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delete kcov_instance;
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}
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ErrorOr<NonnullLockRefPtr<OpenFileDescription>> KCOVDevice::open(int options)
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{
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auto pid = Process::current().pid();
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if (proc_instance->get(pid).has_value())
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return EBUSY; // This process already open()ed the kcov device
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auto kcov_instance = new KCOVInstance(pid);
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kcov_instance->set_state(KCOVInstance::OPENED);
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proc_instance->set(pid, kcov_instance);
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return Device::open(options);
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}
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ErrorOr<void> KCOVDevice::ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg)
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{
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auto thread = Thread::current();
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auto tid = thread->tid();
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auto pid = thread->pid();
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auto maybe_kcov_instance = proc_instance->get(pid);
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if (!maybe_kcov_instance.has_value())
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return ENXIO; // This proc hasn't opened the kcov dev yet
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auto kcov_instance = maybe_kcov_instance.value();
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SpinlockLocker locker(kcov_instance->spinlock());
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switch (request) {
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case KCOV_SETBUFSIZE:
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if (kcov_instance->state() >= KCOVInstance::TRACING)
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return EBUSY;
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return kcov_instance->buffer_allocate((FlatPtr)arg.unsafe_userspace_ptr());
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case KCOV_ENABLE:
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if (kcov_instance->state() >= KCOVInstance::TRACING)
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return EBUSY;
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if (!kcov_instance->has_buffer())
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return ENOBUFS;
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VERIFY(kcov_instance->state() == KCOVInstance::OPENED);
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kcov_instance->set_state(KCOVInstance::TRACING);
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thread_instance->set(tid, kcov_instance);
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return {};
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case KCOV_DISABLE: {
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auto maybe_kcov_instance = thread_instance->get(tid);
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if (!maybe_kcov_instance.has_value())
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return ENOENT;
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VERIFY(kcov_instance->state() == KCOVInstance::TRACING);
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kcov_instance->set_state(KCOVInstance::OPENED);
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thread_instance->remove(tid);
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return {};
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}
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default:
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return EINVAL;
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}
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}
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ErrorOr<NonnullLockRefPtr<Memory::VMObject>> KCOVDevice::vmobject_for_mmap(Process& process, Memory::VirtualRange const&, u64&, bool)
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{
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auto pid = process.pid();
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auto maybe_kcov_instance = proc_instance->get(pid);
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VERIFY(maybe_kcov_instance.has_value()); // Should happen on fd open()
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auto kcov_instance = maybe_kcov_instance.value();
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if (!kcov_instance->vmobject())
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return ENOBUFS; // mmaped, before KCOV_SETBUFSIZE
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return *kcov_instance->vmobject();
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}
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}
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