From: Huacai Chen chenhc@lemote.com Subject: zboot: fix stack protector in compressed boot phase

Call __stack_chk_guard_setup() in decompress_kernel() is too late that stack checking always fails for decompress_kernel() itself. So remove __stack_chk_guard_setup() and initialize __stack_chk_guard before we call decompress_kernel().

Original code comes from ARM but also used for MIPS and SH, so fix them together. If without this fix, compressed booting of these archs will fail because stack checking is enabled by default (>=4.16).

Link: http://lkml.kernel.org/r/1522226933-29317-1-git-send-email-chenhc@lemote.com Fixes: 8779657d29c0 ("stackprotector: Introduce CONFIG_CC_STACKPROTECTOR_STRONG") Signed-off-by: Huacai Chen chenhc@lemote.com Acked-by: James Hogan jhogan@kernel.org Acked-by: Kees Cook keescook@chromium.org Acked-by: Rich Felker dalias@libc.org Cc: Ralf Baechle ralf@linux-mips.org Cc: Russell King linux@arm.linux.org.uk Cc: Yoshinori Sato ysato@users.sourceforge.jp Cc: Ingo Molnar mingo@elte.hu Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

arch/arm/boot/compressed/misc.c | 9 +-------- arch/mips/boot/compressed/decompress.c | 9 +-------- arch/sh/boot/compressed/misc.c | 9 +-------- 3 files changed, 3 insertions(+), 24 deletions(-)

diff -puN arch/arm/boot/compressed/misc.c~zboot-fix-stack-protector-in-compressed-boot-phase arch/arm/boot/compressed/misc.c --- a/arch/arm/boot/compressed/misc.c~zboot-fix-stack-protector-in-compressed-boot-phase +++ a/arch/arm/boot/compressed/misc.c @@ -128,12 +128,7 @@ asmlinkage void __div0(void) error("Attempting division by 0!"); }

-unsigned long __stack_chk_guard; - -void __stack_chk_guard_setup(void) -{ - __stack_chk_guard = 0x000a0dff; -} +const unsigned long __stack_chk_guard = 0x000a0dff;

void __stack_chk_fail(void) { @@ -150,8 +145,6 @@ decompress_kernel(unsigned long output_s { int ret;

- __stack_chk_guard_setup(); - output_data = (unsigned char *)output_start; free_mem_ptr = free_mem_ptr_p; free_mem_end_ptr = free_mem_ptr_end_p; diff -puN arch/mips/boot/compressed/decompress.c~zboot-fix-stack-protector-in-compressed-boot-phase arch/mips/boot/compressed/decompress.c --- a/arch/mips/boot/compressed/decompress.c~zboot-fix-stack-protector-in-compressed-boot-phase +++ a/arch/mips/boot/compressed/decompress.c @@ -76,12 +76,7 @@ void error(char *x) #include "../../../../lib/decompress_unxz.c" #endif

-unsigned long __stack_chk_guard; - -void __stack_chk_guard_setup(void) -{ - __stack_chk_guard = 0x000a0dff; -} +const unsigned long __stack_chk_guard = 0x000a0dff;

void __stack_chk_fail(void) { @@ -92,8 +87,6 @@ void decompress_kernel(unsigned long boo { unsigned long zimage_start, zimage_size;

- __stack_chk_guard_setup(); - zimage_start = (unsigned long)(&__image_begin); zimage_size = (unsigned long)(&__image_end) - (unsigned long)(&__image_begin); diff -puN arch/sh/boot/compressed/misc.c~zboot-fix-stack-protector-in-compressed-boot-phase arch/sh/boot/compressed/misc.c --- a/arch/sh/boot/compressed/misc.c~zboot-fix-stack-protector-in-compressed-boot-phase +++ a/arch/sh/boot/compressed/misc.c @@ -104,12 +104,7 @@ static void error(char *x) while(1); /* Halt */ }

-unsigned long __stack_chk_guard; - -void __stack_chk_guard_setup(void) -{ - __stack_chk_guard = 0x000a0dff; -} +const unsigned long __stack_chk_guard = 0x000a0dff;

void __stack_chk_fail(void) { @@ -130,8 +125,6 @@ void decompress_kernel(void) { unsigned long output_addr;

- __stack_chk_guard_setup(); - #ifdef CONFIG_SUPERH64 output_addr = (CONFIG_MEMORY_START + 0x2000); #else _