From: Greg Kroah-Hartman Date: Thu, 11 Aug 2022 12:57:27 +0000 (+0200) Subject: 5.4-stable patches X-Git-Tag: v5.15.61~244 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=86a154db410448309acf7b39bc80b6198c1b1054;p=thirdparty%2Fkernel%2Fstable-queue.git 5.4-stable patches added patches: x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch --- diff --git a/queue-5.4/series b/queue-5.4/series index 97148cd86d2..2f510f3243e 100644 --- a/queue-5.4/series +++ b/queue-5.4/series @@ -1 +1,2 @@ makefile-link-with-z-noexecstack-no-warn-rwx-segments.patch +x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch diff --git a/queue-5.4/x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch b/queue-5.4/x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch new file mode 100644 index 00000000000..ea8e71118f8 --- /dev/null +++ b/queue-5.4/x86-link-vdso-and-boot-with-z-noexecstack-no-warn-rwx-segments.patch @@ -0,0 +1,84 @@ +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 | 6 ++++++ + arch/x86/entry/vdso/Makefile | 2 +- + 3 files changed, 8 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 +@@ -57,6 +57,12 @@ else + KBUILD_LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \ + && echo "-z noreloc-overflow -pie --no-dynamic-linker") + endif ++ ++KBUILD_LDFLAGS += -z noexecstack ++ifeq ($(CONFIG_LD_IS_BFD),y) ++KBUILD_LDFLAGS += $(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 +@@ -178,7 +178,7 @@ quiet_cmd_vdso = VDSO $@ + sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@' + + VDSO_LDFLAGS = -shared --hash-style=both --build-id \ +- $(call ld-option, --eh-frame-hdr) -Bsymbolic ++ $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack + GCOV_PROFILE := n + + quiet_cmd_vdso_and_check = VDSO $@