diff options
| author | Jinjie Ruan <ruanjinjie@huawei.com> | 2024-06-27 10:38:44 +0300 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2024-07-02 11:18:43 +0300 |
| commit | 2335c9cb831faba1a4efcc612886073b6f175fe4 (patch) | |
| tree | 62686beaccac30cdba1a08cb6251107432eb3a4e /arch | |
| parent | ed0f941022515ff40473ea5335769a5dc2524a3f (diff) | |
| download | linux-2335c9cb831faba1a4efcc612886073b6f175fe4.tar.xz | |
ARM: 9407/1: Add support for STACKLEAK gcc plugin
Add the STACKLEAK gcc plugin to arm32 by adding the helper used by
stackleak common code: on_thread_stack(). It initialize the stack with the
poison value before returning from system calls which improves the kernel
security. Additionally, this disables the plugin in EFI stub code and
decompress code, which are out of scope for the protection.
Before the test on Qemu versatilepb board:
# echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
lkdtm: Performing direct entry STACKLEAK_ERASING
lkdtm: XFAIL: stackleak is not supported on this arch (HAVE_ARCH_STACKLEAK=n)
After:
# echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
lkdtm: Performing direct entry STACKLEAK_ERASING
lkdtm: stackleak stack usage:
high offset: 80 bytes
current: 280 bytes
lowest: 696 bytes
tracked: 696 bytes
untracked: 192 bytes
poisoned: 7220 bytes
low offset: 4 bytes
lkdtm: OK: the rest of the thread stack is properly erased
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/stacktrace.h | 7 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 3 |
4 files changed, 12 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 08572703d94d..26a01ad4087c 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -86,6 +86,7 @@ config ARM select HAVE_ARCH_PFN_VALID select HAVE_ARCH_SECCOMP select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT + select HAVE_ARCH_STACKLEAK select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 6bca03c0c7f0..945b5975fce2 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -9,6 +9,7 @@ OBJS = HEAD = head.o OBJS += misc.o decompress.o +CFLAGS_decompress.o += $(DISABLE_STACKLEAK_PLUGIN) ifeq ($(CONFIG_DEBUG_UNCOMPRESS),y) OBJS += debug.o AFLAGS_head.o += -DDEBUG diff --git a/arch/arm/include/asm/stacktrace.h b/arch/arm/include/asm/stacktrace.h index 360f0d2406bf..f80a85b091d6 100644 --- a/arch/arm/include/asm/stacktrace.h +++ b/arch/arm/include/asm/stacktrace.h @@ -26,6 +26,13 @@ struct stackframe { #endif }; +static inline bool on_thread_stack(void) +{ + unsigned long delta = current_stack_pointer ^ (unsigned long)current->stack; + + return delta < THREAD_SIZE; +} + static __always_inline void arm_get_current_stackframe(struct pt_regs *regs, struct stackframe *frame) { diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 5c31e9de7a60..f379c852dcb7 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -119,6 +119,9 @@ no_work_pending: ct_user_enter save = 0 +#ifdef CONFIG_GCC_PLUGIN_STACKLEAK + bl stackleak_erase_on_task_stack +#endif restore_user_regs fast = 0, offset = 0 ENDPROC(ret_to_user_from_irq) ENDPROC(ret_to_user) |