afaef01c00
The STACKLEAK feature (initially developed by PaX Team) has the following benefits: 1. Reduces the information that can be revealed through kernel stack leak bugs. The idea of erasing the thread stack at the end of syscalls is similar to CONFIG_PAGE_POISONING and memzero_explicit() in kernel crypto, which all comply with FDP_RIP.2 (Full Residual Information Protection) of the Common Criteria standard. 2. Blocks some uninitialized stack variable attacks (e.g. CVE-2017-17712, CVE-2010-2963). That kind of bugs should be killed by improving C compilers in future, which might take a long time. This commit introduces the code filling the used part of the kernel stack with a poison value before returning to userspace. Full STACKLEAK feature also contains the gcc plugin which comes in a separate commit. The STACKLEAK feature is ported from grsecurity/PaX. More information at: https://grsecurity.net/ https://pax.grsecurity.net/ This code is modified from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on our understanding of the code. Changes or omissions from the original code are ours and don't reflect the original grsecurity/PaX code. Performance impact: Hardware: Intel Core i7-4770, 16 GB RAM Test #1: building the Linux kernel on a single core 0.91% slowdown Test #2: hackbench -s 4096 -l 2000 -g 15 -f 25 -P 4.2% slowdown So the STACKLEAK description in Kconfig includes: "The tradeoff is the performance impact: on a single CPU system kernel compilation sees a 1% slowdown, other systems and workloads may vary and you are advised to test this feature on your expected workload before deploying it". Signed-off-by: Alexander Popov <alex.popov@linux.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
133 lines
4.2 KiB
Makefile
133 lines
4.2 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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#
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# Makefile for the linux kernel.
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#
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obj-y = fork.o exec_domain.o panic.o \
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cpu.o exit.o softirq.o resource.o \
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sysctl.o sysctl_binary.o capability.o ptrace.o user.o \
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signal.o sys.o umh.o workqueue.o pid.o task_work.o \
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extable.o params.o \
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kthread.o sys_ni.o nsproxy.o \
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notifier.o ksysfs.o cred.o reboot.o \
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async.o range.o smpboot.o ucount.o
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obj-$(CONFIG_MODULES) += kmod.o
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obj-$(CONFIG_MULTIUSER) += groups.o
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ifdef CONFIG_FUNCTION_TRACER
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# Do not trace internal ftrace files
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CFLAGS_REMOVE_irq_work.o = $(CC_FLAGS_FTRACE)
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endif
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# Prevents flicker of uninteresting __do_softirq()/__local_bh_disable_ip()
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# in coverage traces.
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KCOV_INSTRUMENT_softirq.o := n
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# These are called from save_stack_trace() on slub debug path,
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# and produce insane amounts of uninteresting coverage.
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KCOV_INSTRUMENT_module.o := n
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KCOV_INSTRUMENT_extable.o := n
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# Don't self-instrument.
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KCOV_INSTRUMENT_kcov.o := n
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KASAN_SANITIZE_kcov.o := n
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# cond_syscall is currently not LTO compatible
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CFLAGS_sys_ni.o = $(DISABLE_LTO)
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obj-y += sched/
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obj-y += locking/
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obj-y += power/
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obj-y += printk/
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obj-y += irq/
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obj-y += rcu/
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obj-y += livepatch/
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obj-y += dma/
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obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o
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obj-$(CONFIG_FREEZER) += freezer.o
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obj-$(CONFIG_PROFILING) += profile.o
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obj-$(CONFIG_STACKTRACE) += stacktrace.o
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obj-y += time/
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obj-$(CONFIG_FUTEX) += futex.o
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ifeq ($(CONFIG_COMPAT),y)
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obj-$(CONFIG_FUTEX) += futex_compat.o
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endif
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obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
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obj-$(CONFIG_SMP) += smp.o
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ifneq ($(CONFIG_SMP),y)
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obj-y += up.o
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endif
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obj-$(CONFIG_UID16) += uid16.o
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obj-$(CONFIG_MODULES) += module.o
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obj-$(CONFIG_MODULE_SIG) += module_signing.o
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obj-$(CONFIG_KALLSYMS) += kallsyms.o
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obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
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obj-$(CONFIG_CRASH_CORE) += crash_core.o
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obj-$(CONFIG_KEXEC_CORE) += kexec_core.o
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obj-$(CONFIG_KEXEC) += kexec.o
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obj-$(CONFIG_KEXEC_FILE) += kexec_file.o
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obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o
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obj-$(CONFIG_COMPAT) += compat.o
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obj-$(CONFIG_CGROUPS) += cgroup/
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obj-$(CONFIG_UTS_NS) += utsname.o
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obj-$(CONFIG_USER_NS) += user_namespace.o
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obj-$(CONFIG_PID_NS) += pid_namespace.o
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obj-$(CONFIG_IKCONFIG) += configs.o
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obj-$(CONFIG_SMP) += stop_machine.o
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obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
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obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
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obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
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obj-$(CONFIG_AUDIT_WATCH) += audit_watch.o audit_fsnotify.o
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obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
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obj-$(CONFIG_GCOV_KERNEL) += gcov/
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obj-$(CONFIG_KCOV) += kcov.o
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obj-$(CONFIG_KPROBES) += kprobes.o
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obj-$(CONFIG_FAIL_FUNCTION) += fail_function.o
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obj-$(CONFIG_KGDB) += debug/
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obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
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obj-$(CONFIG_LOCKUP_DETECTOR) += watchdog.o
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obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF) += watchdog_hld.o
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obj-$(CONFIG_SECCOMP) += seccomp.o
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obj-$(CONFIG_RELAY) += relay.o
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obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
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obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
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obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
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obj-$(CONFIG_TRACEPOINTS) += tracepoint.o
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obj-$(CONFIG_LATENCYTOP) += latencytop.o
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obj-$(CONFIG_ELFCORE) += elfcore.o
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obj-$(CONFIG_FUNCTION_TRACER) += trace/
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obj-$(CONFIG_TRACING) += trace/
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obj-$(CONFIG_TRACE_CLOCK) += trace/
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obj-$(CONFIG_RING_BUFFER) += trace/
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obj-$(CONFIG_TRACEPOINTS) += trace/
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obj-$(CONFIG_IRQ_WORK) += irq_work.o
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obj-$(CONFIG_CPU_PM) += cpu_pm.o
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obj-$(CONFIG_BPF) += bpf/
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obj-$(CONFIG_PERF_EVENTS) += events/
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obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o
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obj-$(CONFIG_PADATA) += padata.o
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obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
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obj-$(CONFIG_JUMP_LABEL) += jump_label.o
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obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
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obj-$(CONFIG_TORTURE_TEST) += torture.o
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obj-$(CONFIG_HAS_IOMEM) += iomem.o
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obj-$(CONFIG_ZONE_DEVICE) += memremap.o
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obj-$(CONFIG_RSEQ) += rseq.o
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obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o
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KASAN_SANITIZE_stackleak.o := n
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KCOV_INSTRUMENT_stackleak.o := n
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$(obj)/configs.o: $(obj)/config_data.h
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targets += config_data.gz
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$(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
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$(call if_changed,gzip)
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filechk_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;")
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targets += config_data.h
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$(obj)/config_data.h: $(obj)/config_data.gz FORCE
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$(call filechk,ikconfiggz)
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