From 7bbaf27d9c83037b6e60a818e57bdbedf6bc15be Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Thu, 5 Apr 2018 16:18:18 -0700 Subject: [PATCH] zboot: fix stack protector in compressed boot phase Calling __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 Acked-by: James Hogan Acked-by: Kees Cook Acked-by: Rich Felker Cc: Ralf Baechle Cc: Russell King Cc: Yoshinori Sato Cc: Ingo Molnar Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c index 16a8a804e958..e8fe51f4e97a 100644 --- a/arch/arm/boot/compressed/misc.c +++ b/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_start, unsigned long free_mem_ptr_p, { 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 --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c index fdf99e9dd4c3..81df9047e110 100644 --- a/arch/mips/boot/compressed/decompress.c +++ b/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 boot_heap_start) { 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 --git a/arch/sh/boot/compressed/misc.c b/arch/sh/boot/compressed/misc.c index 627ce8e75e01..c15cac9251b9 100644 --- a/arch/sh/boot/compressed/misc.c +++ b/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 -- GitLab