From fa9c10a1618ada558507f0d99611cf23f619d216 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 11 Aug 2022 13:45:57 +0200 Subject: [PATCH] 5.4-stable patches added patches: makefile-link-with-z-noexecstack-no-warn-rwx-segments.patch --- ...h-z-noexecstack-no-warn-rwx-segments.patch | 59 +++++++++++++++++++ queue-5.4/series | 1 + 2 files changed, 60 insertions(+) create mode 100644 queue-5.4/makefile-link-with-z-noexecstack-no-warn-rwx-segments.patch create mode 100644 queue-5.4/series diff --git a/queue-5.4/makefile-link-with-z-noexecstack-no-warn-rwx-segments.patch b/queue-5.4/makefile-link-with-z-noexecstack-no-warn-rwx-segments.patch new file mode 100644 index 00000000000..62874fc6aba --- /dev/null +++ b/queue-5.4/makefile-link-with-z-noexecstack-no-warn-rwx-segments.patch @@ -0,0 +1,59 @@ +From 0d362be5b14200b77ecc2127936a5ff82fbffe41 Mon Sep 17 00:00:00 2001 +From: Nick Desaulniers +Date: Wed, 10 Aug 2022 15:24:40 -0700 +Subject: Makefile: link with -z noexecstack --no-warn-rwx-segments + +From: Nick Desaulniers + +commit 0d362be5b14200b77ecc2127936a5ff82fbffe41 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: vmlinux: 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: 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 +--- + Makefile | 5 +++++ + 1 file changed, 5 insertions(+) + +--- a/Makefile ++++ b/Makefile +@@ -932,6 +932,11 @@ KBUILD_CFLAGS += $(KCFLAGS) + KBUILD_LDFLAGS_MODULE += --build-id + LDFLAGS_vmlinux += --build-id + ++KBUILD_LDFLAGS += -z noexecstack ++ifeq ($(CONFIG_LD_IS_BFD),y) ++KBUILD_LDFLAGS += $(call ld-option,--no-warn-rwx-segments) ++endif ++ + ifeq ($(CONFIG_STRIP_ASM_SYMS),y) + LDFLAGS_vmlinux += $(call ld-option, -X,) + endif diff --git a/queue-5.4/series b/queue-5.4/series new file mode 100644 index 00000000000..97148cd86d2 --- /dev/null +++ b/queue-5.4/series @@ -0,0 +1 @@ +makefile-link-with-z-noexecstack-no-warn-rwx-segments.patch -- 2.47.3