Revision c715b72c1ba406f133217b509044c38d8e714a37 authored by Kees Cook on 18 August 2017, 22:16:31 UTC, committed by Linus Torvalds on 18 August 2017, 22:32:02 UTC
Moving the x86_64 and arm64 PIE base from 0x555555554000 to 0x000100000000 broke AddressSanitizer. This is a partial revert of: eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE") 02445990a96e ("arm64: move ELF_ET_DYN_BASE to 4GB / 4MB") The AddressSanitizer tool has hard-coded expectations about where executable mappings are loaded. The motivation for changing the PIE base in the above commits was to avoid the Stack-Clash CVEs that allowed executable mappings to get too close to heap and stack. This was mainly a problem on 32-bit, but the 64-bit bases were moved too, in an effort to proactively protect those systems (proofs of concept do exist that show 64-bit collisions, but other recent changes to fix stack accounting and setuid behaviors will minimize the impact). The new 32-bit PIE base is fine for ASan (since it matches the ET_EXEC base), so only the 64-bit PIE base needs to be reverted to let x86 and arm64 ASan binaries run again. Future changes to the 64-bit PIE base on these architectures can be made optional once a more dynamic method for dealing with AddressSanitizer is found. (e.g. always loading PIE into the mmap region for marked binaries.) Link: http://lkml.kernel.org/r/20170807201542.GA21271@beast Fixes: eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE") Fixes: 02445990a96e ("arm64: move ELF_ET_DYN_BASE to 4GB / 4MB") Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Kostya Serebryany <kcc@google.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Makefile.headersinst
# ==========================================================================
# Installing headers
#
# All headers under include/uapi, include/generated/uapi,
# arch/<arch>/include/uapi and arch/<arch>/include/generated/uapi are
# exported.
# They are preprocessed to remove __KERNEL__ section of the file.
#
# ==========================================================================
PHONY := __headers
__headers:
include scripts/Kbuild.include
srcdir := $(srctree)/$(obj)
# When make is run under a fakechroot environment, the function
# $(wildcard $(srcdir)/*/.) doesn't only return directories, but also regular
# files. So, we are using a combination of sort/dir/wildcard which works
# with fakechroot.
subdirs := $(patsubst $(srcdir)/%/,%,\
$(filter-out $(srcdir)/,\
$(sort $(dir $(wildcard $(srcdir)/*/)))))
# Recursion
__headers: $(subdirs)
.PHONY: $(subdirs)
$(subdirs):
$(Q)$(MAKE) $(hdr-inst)=$(obj)/$@ dst=$(dst)/$@
# Skip header install/check for include/uapi and arch/$(hdr-arch)/include/uapi.
# We have only sub-directories there.
skip-inst := $(if $(filter %/uapi,$(obj)),1)
ifeq ($(skip-inst),)
# Kbuild file is optional
kbuild-file := $(srctree)/$(obj)/Kbuild
-include $(kbuild-file)
installdir := $(INSTALL_HDR_PATH)/$(dst)
gendir := $(objtree)/$(subst include/,include/generated/,$(obj))
header-files := $(notdir $(wildcard $(srcdir)/*.h))
header-files += $(notdir $(wildcard $(srcdir)/*.agh))
header-files := $(filter-out $(no-export-headers), $(header-files))
genhdr-files := $(notdir $(wildcard $(gendir)/*.h))
genhdr-files := $(filter-out $(header-files), $(genhdr-files))
# files used to track state of install/check
install-file := $(installdir)/.install
check-file := $(installdir)/.check
# all headers files for this dir
all-files := $(header-files) $(genhdr-files)
output-files := $(addprefix $(installdir)/, $(all-files))
ifneq ($(mandatory-y),)
missing := $(filter-out $(all-files),$(mandatory-y))
ifneq ($(missing),)
$(error Some mandatory headers ($(missing)) are missing in $(obj))
endif
endif
# Work out what needs to be removed
oldheaders := $(patsubst $(installdir)/%,%,$(wildcard $(installdir)/*.h))
unwanted := $(filter-out $(all-files),$(oldheaders))
# Prefix unwanted with full paths to $(INSTALL_HDR_PATH)
unwanted-file := $(addprefix $(installdir)/, $(unwanted))
printdir = $(patsubst $(INSTALL_HDR_PATH)/%/,%,$(dir $@))
quiet_cmd_install = INSTALL $(printdir) ($(words $(all-files))\
file$(if $(word 2, $(all-files)),s))
cmd_install = \
$(CONFIG_SHELL) $< $(installdir) $(srcdir) $(header-files); \
$(CONFIG_SHELL) $< $(installdir) $(gendir) $(genhdr-files); \
touch $@
quiet_cmd_remove = REMOVE $(unwanted)
cmd_remove = rm -f $(unwanted-file)
quiet_cmd_check = CHECK $(printdir) ($(words $(all-files)) files)
# Headers list can be pretty long, xargs helps to avoid
# the "Argument list too long" error.
cmd_check = for f in $(all-files); do \
echo "$(installdir)/$${f}"; done \
| xargs \
$(PERL) $< $(INSTALL_HDR_PATH)/include $(SRCARCH); \
touch $@
ifndef HDRCHECK
# Rules for installing headers
__headers: $(install-file)
@:
targets += $(install-file)
$(install-file): scripts/headers_install.sh \
$(addprefix $(srcdir)/,$(header-files)) \
$(addprefix $(gendir)/,$(genhdr-files)) FORCE
$(if $(unwanted),$(call cmd,remove),)
$(if $(wildcard $(dir $@)),,$(shell mkdir -p $(dir $@)))
$(call if_changed,install)
else
__headers: $(check-file)
@:
targets += $(check-file)
$(check-file): scripts/headers_check.pl $(output-files) FORCE
$(call if_changed,check)
endif
targets := $(wildcard $(sort $(targets)))
cmd_files := $(wildcard \
$(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
ifneq ($(cmd_files),)
include $(cmd_files)
endif
endif # skip-inst
.PHONY: $(PHONY)
PHONY += FORCE
FORCE: ;
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