From: Joel Peshkin joel.peshkin@broadcom.com
Add support for stack protector for UBOOT, SPL, and TPL as well as new pytest for stackprotector
Signed-off-by: Joel Peshkin joel.peshkin@broadcom.com
Adjust UEFI build flags. Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de --- v10: Adjust UEFI build flags. Remove unused DECLARE_GLOBAL_DATA_PTR in cmd/stackprot_test.c. Add missing include asm/global_data.h in common/stackprot.c. --- MAINTAINERS | 7 +++++++ Makefile | 5 +++++ arch/arm/config.mk | 3 ++- arch/riscv/lib/Makefile | 1 + arch/x86/config.mk | 2 +- cmd/Kconfig | 9 +++++++++ cmd/Makefile | 1 + cmd/stackprot_test.c | 19 +++++++++++++++++++ common/Kconfig | 17 +++++++++++++++++ common/Makefile | 1 + common/stackprot.c | 20 ++++++++++++++++++++ configs/sandbox_defconfig | 2 ++ scripts/Makefile.spl | 6 ++++++ test/py/tests/test_stackprotector.py | 14 ++++++++++++++ 14 files changed, 105 insertions(+), 2 deletions(-) create mode 100644 cmd/stackprot_test.c create mode 100644 common/stackprot.c create mode 100644 test/py/tests/test_stackprotector.py
diff --git a/MAINTAINERS b/MAINTAINERS index c6dd9bf838..2d267aeff2 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1062,6 +1062,13 @@ F: include/sqfs.h F: cmd/sqfs.c F: test/py/tests/test_fs/test_squashfs/
+STACKPROTECTOR +M: Joel Peshkin joel.peshkin@broadcom.com +S: Maintained +F: common/stackprot.c +F: cmd/stackprot_test.c +F: test/py/tests/test_stackprotector.py + TARGET_BCMNS3 M: Bharat Gooty bharat.gooty@broadcom.com M: Rayagonda Kokatanur rayagonda.kokatanur@broadcom.com diff --git a/Makefile b/Makefile index 193aa4d1c9..30565255b5 100644 --- a/Makefile +++ b/Makefile @@ -676,7 +676,12 @@ else KBUILD_CFLAGS += -O2 endif
+ifeq ($(CONFIG_STACKPROTECTOR),y) +KBUILD_CFLAGS += $(call cc-option,-fstack-protector-strong) +CFLAGS_EFI += $(call cc-option,-fno-stack-protector) +else KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) +endif KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks)
# disable stringop warnings in gcc 8+ diff --git a/arch/arm/config.mk b/arch/arm/config.mk index 4153f7e371..e79f0104b9 100644 --- a/arch/arm/config.mk +++ b/arch/arm/config.mk @@ -11,7 +11,8 @@ CONFIG_STANDALONE_LOAD_ADDR = 0xc100000 endif endif
-CFLAGS_NON_EFI := -fno-pic -ffixed-r9 -ffunction-sections -fdata-sections +CFLAGS_NON_EFI := -fno-pic -ffixed-r9 -ffunction-sections -fdata-sections \ + -fstack-protector-strong CFLAGS_EFI := -fpic -fshort-wchar
LDFLAGS_FINAL += --gc-sections diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index ff0677aa96..d08cbe9b79 100644 --- a/arch/riscv/lib/Makefile +++ b/arch/riscv/lib/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_SPL_BUILD) += spl.o obj-y += fdt_fixup.o
# For building EFI apps +CFLAGS_NON_EFI := -fstack-protector-strong CFLAGS_$(EFI_CRT0) := $(CFLAGS_EFI) CFLAGS_REMOVE_$(EFI_CRT0) := $(CFLAGS_NON_EFI)
diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 3067702858..7a8242562d 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -42,7 +42,7 @@ OBJCOPYFLAGS_EFI := -j .text -j .sdata -j .data -j .dynamic -j .dynsym \ # Compiler flags to be added when building UEFI applications CFLAGS_EFI := -fpic -fshort-wchar # Compiler flags to be removed when building UEFI applications -CFLAGS_NON_EFI := -mregparm=3 +CFLAGS_NON_EFI := -mregparm=3 -fstack-protector-strong
ifeq ($(CONFIG_EFI_STUB_64BIT),) CFLAGS_EFI += $(call cc-option, -mno-red-zone) diff --git a/cmd/Kconfig b/cmd/Kconfig index c735e81b37..420c1f0f94 100644 --- a/cmd/Kconfig +++ b/cmd/Kconfig @@ -2324,6 +2324,15 @@ config CMD_AVB avb read_part_hex - read data from partition and output to stdout avb write_part - write data to partition avb verify - run full verification chain + +config CMD_STACKPROTECTOR_TEST + bool "Test command for stack protector" + depends on STACKPROTECTOR + help + Enable stackprot_test command + The stackprot_test command will force a stack overrun to test + the stack smashing detection mechanisms. + endmenu
config CMD_UBI diff --git a/cmd/Makefile b/cmd/Makefile index e606ac4e8c..4977fa15f4 100644 --- a/cmd/Makefile +++ b/cmd/Makefile @@ -144,6 +144,7 @@ obj-$(CONFIG_CMD_SPI) += spi.o obj-$(CONFIG_CMD_STRINGS) += strings.o obj-$(CONFIG_CMD_SMC) += smccc.o obj-$(CONFIG_CMD_SYSBOOT) += sysboot.o pxe_utils.o +obj-$(CONFIG_CMD_STACKPROTECTOR_TEST) += stackprot_test.o obj-$(CONFIG_CMD_TERMINAL) += terminal.o obj-$(CONFIG_CMD_TIME) += time.o obj-$(CONFIG_CMD_TIMER) += timer.o diff --git a/cmd/stackprot_test.c b/cmd/stackprot_test.c new file mode 100644 index 0000000000..36f5bac8d2 --- /dev/null +++ b/cmd/stackprot_test.c @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2021 Broadcom + */ + +#include <common.h> +#include <command.h> + +static int do_test_stackprot_fail(struct cmd_tbl *cmdtp, int flag, int argc, + char *const argv[]) +{ + char a[128]; + + memset(a, 0xa5, 512); + return 0; +} + +U_BOOT_CMD(stackprot_test, 1, 1, do_test_stackprot_fail, + "test stack protector fail", ""); diff --git a/common/Kconfig b/common/Kconfig index 0e36dfd236..26496f9a2e 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -618,6 +618,23 @@ config TPL_HASH and the algorithms it supports are defined in common/hash.c. See also CMD_HASH for command-line access.
+config STACKPROTECTOR + bool "Stack Protector buffer overflow detection" + default n + help + Enable stack smash detection through compiler's stack-protector + canary logic + +config SPL_STACKPROTECTOR + bool "Stack Protector buffer overflow detection for SPL" + depends on STACKPROTECTOR && SPL + default n + +config TPL_STACKPROTECTOR + bool "Stack Protector buffer overflow detection for TPL" + depends on STACKPROTECTOR && TPL + default n + endmenu
menu "Update support" diff --git a/common/Makefile b/common/Makefile index 215b8b26fd..bdad9655a9 100644 --- a/common/Makefile +++ b/common/Makefile @@ -137,4 +137,5 @@ obj-$(CONFIG_CMD_LOADB) += xyzModem.o obj-$(CONFIG_$(SPL_TPL_)YMODEM_SUPPORT) += xyzModem.o
obj-$(CONFIG_AVB_VERIFY) += avb_verify.o +obj-$(CONFIG_$(SPL_TPL_)STACKPROTECTOR) += stackprot.o obj-$(CONFIG_SCP03) += scp03.o diff --git a/common/stackprot.c b/common/stackprot.c new file mode 100644 index 0000000000..d5b7061665 --- /dev/null +++ b/common/stackprot.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2021 Broadcom + */ + +#include <common.h> +#include <asm/global_data.h> + +DECLARE_GLOBAL_DATA_PTR; + +unsigned long __stack_chk_guard = (unsigned long)(0xfeedf00ddeadbeef & ~0UL); + +void __stack_chk_fail(void) +{ + void *ra; + + ra = __builtin_extract_return_addr(__builtin_return_address(0)); + panic("Stack smashing detected in function:\n%p relocated from %p", + ra, ra - gd->reloc_off); +} diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig index 5da8d1679e..bc14da668d 100644 --- a/configs/sandbox_defconfig +++ b/configs/sandbox_defconfig @@ -25,6 +25,7 @@ CONFIG_LOG_SYSLOG=y CONFIG_LOG_ERROR_RETURN=y CONFIG_DISPLAY_BOARDINFO_LATE=y CONFIG_MISC_INIT_F=y +CONFIG_STACKPROTECTOR=y CONFIG_ANDROID_AB=y CONFIG_CMD_CPU=y CONFIG_CMD_LICENSE=y @@ -97,6 +98,7 @@ CONFIG_CMD_CRAMFS=y CONFIG_CMD_EXT4_WRITE=y CONFIG_CMD_SQUASHFS=y CONFIG_CMD_MTDPARTS=y +CONFIG_CMD_STACKPROTECTOR_TEST=y CONFIG_MAC_PARTITION=y CONFIG_AMIGA_PARTITION=y CONFIG_OF_CONTROL=y diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl index ca988224da..c69525fa74 100644 --- a/scripts/Makefile.spl +++ b/scripts/Makefile.spl @@ -67,6 +67,12 @@ include $(srctree)/scripts/Makefile.lib KBUILD_CFLAGS += -ffunction-sections -fdata-sections LDFLAGS_FINAL += --gc-sections
+ifeq ($(CONFIG_$(SPL_TPL_)STACKPROTECTOR),y) +KBUILD_CFLAGS += -fstack-protector-strong +else +KBUILD_CFLAGS += -fno-stack-protector +endif + # FIX ME cpp_flags := $(KBUILD_CPPFLAGS) $(PLATFORM_CPPFLAGS) $(UBOOTINCLUDE) \ $(NOSTDINC_FLAGS) diff --git a/test/py/tests/test_stackprotector.py b/test/py/tests/test_stackprotector.py new file mode 100644 index 0000000000..b009437e5e --- /dev/null +++ b/test/py/tests/test_stackprotector.py @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2021 Broadcom + +import pytest +import signal + +@pytest.mark.buildconfigspec('cmd_stackprotector_test') +def test_stackprotector(u_boot_console): + """Test that the stackprotector function works.""" + + u_boot_console.run_command('stackprot_test',wait_for_prompt=False) + expected_response = 'Stack smashing detected' + u_boot_console.wait_for(expected_response) + u_boot_console.restart_uboot() -- 2.30.2