From 1add2425c9e63b2db99076a0981c79969b27b472 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 11 Aug 2022 13:05:30 +0200 Subject: [PATCH] 4.9-stable patches added patches: x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch --- queue-4.9/series | 1 + ...h-z-noexecstack-no-warn-rwx-segments.patch | 82 +++++++++++++++++++ 2 files changed, 83 insertions(+) create mode 100644 queue-4.9/x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch diff --git a/queue-4.9/series b/queue-4.9/series index ce94b4cb78d..3fc8e5e3fbc 100644 --- a/queue-4.9/series +++ b/queue-4.9/series @@ -22,3 +22,4 @@ acpi-video-force-backlight-native-for-some-tongfang-devices.patch acpi-video-shortening-quirk-list-by-identifying-clevo-by-board_name-only.patch random-only-call-boot_init_stack_canary-once.patch macintosh-adb-fix-oob-read-in-do_adb_query-function.patch +x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch diff --git a/queue-4.9/x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch b/queue-4.9/x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch new file mode 100644 index 00000000000..67f25305527 --- /dev/null +++ b/queue-4.9/x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch @@ -0,0 +1,82 @@ +From ffcf9c5700e49c0aee42dcba9a12ba21338e8136 Mon Sep 17 00:00:00 2001 +From: Nick Desaulniers +Date: Wed, 10 Aug 2022 15:24:41 -0700 +Subject: x86: link vdso and boot with -z noexecstack --no-warn-rwx-segments + +From: Nick Desaulniers + +commit ffcf9c5700e49c0aee42dcba9a12ba21338e8136 upstream. + +Users of GNU ld (BFD) from binutils 2.39+ will observe multiple +instances of a new warning when linking kernels in the form: + + ld: warning: arch/x86/boot/pmjump.o: missing .note.GNU-stack section implies executable stack + ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker + ld: warning: arch/x86/boot/compressed/vmlinux has a LOAD segment with RWX permissions + +Generally, we would like to avoid the stack being executable. Because +there could be a need for the stack to be executable, assembler sources +have to opt-in to this security feature via explicit creation of the +.note.GNU-stack feature (which compilers create by default) or command +line flag --noexecstack. Or we can simply tell the linker the +production of such sections is irrelevant and to link the stack as +--noexecstack. + +LLVM's LLD linker defaults to -z noexecstack, so this flag isn't +strictly necessary when linking with LLD, only BFD, but it doesn't hurt +to be explicit here for all linkers IMO. --no-warn-rwx-segments is +currently BFD specific and only available in the current latest release, +so it's wrapped in an ld-option check. + +While the kernel makes extensive usage of ELF sections, it doesn't use +permissions from ELF segments. + +Link: https://lore.kernel.org/linux-block/3af4127a-f453-4cf7-f133-a181cce06f73@kernel.dk/ +Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107 +Link: https://github.com/llvm/llvm-project/issues/57009 +Reported-and-tested-by: Jens Axboe +Suggested-by: Fangrui Song +Signed-off-by: Nick Desaulniers +Signed-off-by: Linus Torvalds +Signed-off-by: Greg Kroah-Hartman +--- + arch/x86/boot/Makefile | 2 +- + arch/x86/boot/compressed/Makefile | 4 ++++ + arch/x86/entry/vdso/Makefile | 2 +- + 3 files changed, 6 insertions(+), 2 deletions(-) + +--- a/arch/x86/boot/Makefile ++++ b/arch/x86/boot/Makefile +@@ -100,7 +100,7 @@ $(obj)/zoffset.h: $(obj)/compressed/vmli + AFLAGS_header.o += -I$(objtree)/$(obj) + $(obj)/header.o: $(obj)/zoffset.h + +-LDFLAGS_setup.elf := -m elf_i386 -T ++LDFLAGS_setup.elf := -m elf_i386 -z noexecstack -T + $(obj)/setup.elf: $(src)/setup.ld $(SETUP_OBJS) FORCE + $(call if_changed,ld) + +--- a/arch/x86/boot/compressed/Makefile ++++ b/arch/x86/boot/compressed/Makefile +@@ -54,6 +54,10 @@ else + LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \ + && echo "-z noreloc-overflow -pie --no-dynamic-linker") + endif ++LDFLAGS_vmlinux += -z noexecstack ++ifeq ($(CONFIG_LD_IS_BFD),y) ++LDFLAGS_vmlinux += $(call ld-option,--no-warn-rwx-segments) ++endif + LDFLAGS_vmlinux := -T + + hostprogs-y := mkpiggy +--- a/arch/x86/entry/vdso/Makefile ++++ b/arch/x86/entry/vdso/Makefile +@@ -168,7 +168,7 @@ quiet_cmd_vdso = VDSO $@ + + VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \ + $(call ld-option, --build-id) $(call ld-option, --eh-frame-hdr) \ +- -Bsymbolic ++ -Bsymbolic -z noexecstack + GCOV_PROFILE := n + + # -- 2.47.3